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D R Booth

Publications and source records attributed to D R Booth.

At least 37 records · Page 2Linked to original sources
PubMed1998

Hereditary nephropathic systemic amyloidosis caused by a novel variant apolipoprotein A-I.

We report a family with autosomal-dominant hereditary systemic amyloidosis in three generations, presenting with renal involvement. Two members of the current generation received renal transplants for end-stage renal failure 16 and 18 years ago, and remain very well clinically despite massive visceral amyloidosis. Two other members of this generation, aged 32 and 47 years, have massive systemic amyloid but no clinical disability. Individuals known to be affected in previous generations died of renal failure in early adult life. Amyloid deposits in the proband, one of the transplanted individuals, were composed of apolipoprotein A-I (apoA-I), and among living family members there was complete concordance between amyloidosis and the presence of a novel 9 base pair in-frame deletion mutation in exon 4 of the apoA-I gene, causing a loss of residues Glu70Phe71Trp72. This predicts the acquisition of a single extra positive charge by mature apoA-I, and this variant was detected in the plasma of all carriers. All the previously reported amyloidogenic variants of apoA-I also carry an extra positive charge, indicating that this electrostatic change is likely to be relevant to the amyloidogenicity of apoA-I.

Amyloid↗
PubMed1998

Pyrin/marenostrin mutations in familial Mediterranean fever.

Familial Mediterranean fever (FMF) is an inherited inflammatory disease that is frequently complicated by reactive systemic (AA) amyloidosis. It is principally recognized in certain Mediterranean populations, and the diagnosis depends on clinical features. Four mutations strongly linked to FMF have lately been identified in a gene encoding a novel protein that has been named pyrin or marenostrin. We studied 27 consecutive patients of varied ethnic origin, including an English man, who had classical, probable or possible FMF. Pyrin/marenostrin genotypes were determined, and AA amyloidosis was sought using serum amyloid P component scintigraphy. Among the 23 patients with classical or probable FMF, 17 were homozygotes or compound heterozygotes for pyrin/marenostrin mutations, and in five, only single allele mutations were identified. Two new mutations, T6811 and delta M694, were discovered in addition to the four described previously. No mutations were identified in three of the four patients with possible FMF. Nine patients had AA amyloidosis, but this association was not restricted to any particular genotype. Most patients with FMF have mutations in both pyrin/marenostrin alleles, and genotyping at this locus is a valuable diagnostic test. Unidentified second mutations are likely to occur in FMF patients who have apparently solitary mutations, and therefore genotype results must be interpreted in conjunction with the clinical picture.

Base Sequence↗
PubMed1998

SAA1 alleles as risk factors in reactive systemic AA amyloidosis.

SAA1 is the predominant isoform of acute phase human SAA deposited as AA amyloid fibrils in reactive systemic amyloidosis. It has recently been reported that in the Japanese population, in whom the SAA1 gamma allele occurs with a frequency of 37%, possession of, and especially, homozygosity for this allele is a significant risk factor for AA amyloidosis in adult patients with rheumatoid arthritis (RA). In contrast we report here that in a control sample of 95 healthy adult male Caucasians the SAA1 gamma allele occurs at the much lower frequency of 5.3% and that, among 41 patients with juvenile chronic arthritis (JCA) and AA amyloidosis, there was a highly significantly increased frequency of the SAA1 alpha allele (90.2%), and particularly homozygosity for this allele (80.5%), compared both to the healthy controls (75.8% and 57.9% respectively) and to 8 JCA cases without amyloid (56.3% and 12.5%). A similar trend with respect to frequency of the SAA1 alpha allele and homozygosity for it was observed among 26 adult Caucasian RA patients with AA amyloid and 26 such cases without amyloid, although it did not reach statistical significance. These results suggest that there is probably differential amyloidogenicity amongst the different SAA1 isoforms and indicate that homozygosity for SAA1 alpha and SAA1 gamma in the different populations is a significant risk factor for development of AA amyloidosis. In Caucasian patients with JCA, the presence of the homozygous SAA1 alpha genotype indicates high risk of amyloidosis and should encourage early and aggressive anti-inflammatory therapy to keep circulating SAA levels as low as possible.

Adult↗
PubMed1997

Instability, unfolding and aggregation of human lysozyme variants underlying amyloid fibrillogenesis.

Tissue deposition of soluble proteins as amyloid fibrils underlies a range of fatal diseases. The two naturally occurring human lysozyme variants are both amyloidogenic, and are shown here to be unstable. They aggregate to form amyloid fibrils with transformation of the mainly helical native fold, observed in crystal structures, to the amyloid fibril cross-beta fold. Biophysical studies suggest that partly folded intermediates are involved in fibrillogenesis, and this may be relevant to amyloidosis generally.

Amyloid↗
PubMed1996

Hereditary hepatic and systemic amyloidosis caused by a new deletion/insertion mutation in the apolipoprotein AI gene.

We report a Spanish family with autosomal-dominant non-neuropathic hereditary amyloidosis with a unique hepatic presentation and death from liver failure, usually by the sixth decade. The disease is caused by a previously unreported deletion/insertion mutation in exon 4 of the apolipoprotein AI (apoAI) gene encoding loss of residues 60-71 of normal mature apoAI and insertion at that position of two new residues, ValThr. Affected individuals are heterozygous for this mutation and have both normal apoAI and variant molecules bearing one extra positive charge, as predicted from the DNA sequence. The amyloid fibrils are composed exclusively of NH2-terminal fragments of the variant, ending mainly at positions corresponding to residues 83 and 92 in the mature wild-type sequence. Amyloid fibrils derived from the other three known amyloidogenic apoAI variants are also composed of similar NH2-terminal fragments. All known amyloidogenic apoAI variants carry one extra positive charge in this region, suggesting that it may be responsible for their enhanced amyloidogenicity. In addition to causing a new phenotype, this is the first deletion mutation to be described in association with hereditary amyloidosis and it significantly extends the value of the apoAI model for investigation of molecular mechanisms of amyloid fibrillogenesis.

Adult↗
PubMed1996

Molecular mechanisms of fibrillogenesis and the protective role of amyloid P component: two possible avenues for therapy.

Amyloid deposits regress when the supply of fibril precursor proteins is sufficiently reduced, indicating that amyloid fibrils are degradable in vivo. Serum amyloid P component (SAP), a universal constituent of amyloid deposits, efficiently protects amyloid fibrils from proteolysis in vitro, and may contribute to persistence of amyloid in vivo. Drugs that prevent binding of SAP to amyloid fibrils in vivo should therefore promote regression of amyloid and we are actively seeking such agents. A complementary strategy is identification of critical molecular processes in fibrillogenesis as targets for pharmacological intervention. All amyloidogenic variants of apolipoprotein AI contain an additional positive charge in the N-terminal fibrillogenic region of the protein. This is unlikely to be a coincidence and should be informative about amyloidogenesis by this protein. The two amyloidogenic variants of human lysozyme, caused by the first natural mutations found in its gene, provide a particularly powerful model system because both the crystal structure and folding pathways of wild-type lysozyme are so well characterized. The amyloidogenic variant lysozymes have similar 3D crystal structures to the wild type, but are notably less thermostable. They unfold on heating, lose enzymic activity, and aggregate to form amyloid fibrils in vitro.

Amyloid↗
PubMed1996

Evolution of multiple families of non-LTR retrotransposons in phlebotomine sandflies.

In this paper we report on the diversity and distribution of a set of non-LTR retrotransposon (RTP) reverse transcriptase (RT) sequences isolated from phlebotomine sandflies, and their potential for investigating the evolutionary histories of members of this subfamily of flies (Diptera:Psychodidae, Phlebotominae). The phlebotomine RT sequence families derived from one species were as different from each other as they were from RT sequences derived from other species. When each was used to probe Southern blots of sandfly genomic DNA they hybridized only to the species of source and, usually, to others of the same subgenus, but not to DNA from other subgenera-a hybridization pattern consistent with vertical evolution. There was considerable intraspecific variation in hybridization pattern, suggesting the RTs were part of non-LTR RTPs that are (or were recently) subject to flux in genomic position and copy number. Most of the RT families detected in phlebotomines are monophyletic with respect to previously described RTs, and all are monophyletic with RTs of the F/Jockey (Drosophila melanogaster) type of RTP. Orthologous sequences were isolated from the closely related species Phlebotomus perniciosus and P. tobbi (subgenus Larroussius), and different populations of P. perniciosus. The level of sequence divergence among these orthologous RTs, the subgeneric distribution of each RT family, and the intraspecific variation in hybridization pattern of many of them, indicate this class of sequence will provide genetic markers at the sub-generic level.

Amino Acid Sequence↗
PubMed1995

A novel variant of transthyretin, 59Thr-->Lys, associated with autosomal dominant cardiac amyloidosis in an Italian family.

BACKGROUND: Amyloidosis is a disorder of protein metabolism characterized by extracellular accumulation of abnormal protein fibrils. Different proteins form the fibrils in different forms of the disease, and the condition can be acquired or hereditary. Involvement of the heart is quite common, producing a serious and usually fatal cardiomyopathy. Cardiac amyloidosis is often diagnosed late, and cardiac biopsy together with proper histological examination is essential. Contrary to previous perceptions, there is much recent evidence of effective treatment for several different types of systemic and cardiac amyloidosis, including the most common hereditary form caused by mutations in the transthyretin gene. Chemical and genetic typing of amyloid is therefore of considerable clinical importance. METHODS AND RESULTS: Seven members in two generations of an Italian family presented with cardiac disease inherited as an autosomal dominant and were found to have systemic amyloidosis. Angina pectoris-like pain, an unusual feature in cardiac amyloidosis, was a prominent symptom, possibly related to partial obliteration of the distal coronary arteries by amyloid infiltration. There were also cases of sudden cardiac death. Peripheral and autonomic neuropathy, which are the usual features of hereditary amyloidosis, were present in only two cases, and a diagnosis of acquired, immunoglobulin light chain (AL type) amyloidosis was suspected in the index case before the family history emerged. In fact, the amyloid fibrils were composed of transthyretin, and the two affected individuals from whom DNA was available were both heterozygotes for a single base change in exon 3 of the transthyretin gene, encoding substitution of Lys for the wild-type Thr residue at position 59 in the mature protein. This mutation has not previously been reported. CONCLUSIONS: We have identified a novel mutation in the transthyretin gene encoding 59Thr-->Lys associated with autosomal dominant hereditary systemic amyloidosis in an Italian kindred in whom cardiac involvement was the major feature. This family illustrates the difficulty in diagnosis of cardiac amyloid, the variable clinical phenotype in hereditary amyloidosis even within a family, and the importance of precise fibril typing for correct management in this condition.

Amyloidosis↗
PubMed1995

Transthyretin gene analysis in European patients with suspected familial amyloid polyneuropathy.

We investigated 99 patients from 64 European families (51 French, 11 British, one Italian and one Spanish) with suspected familial amyloid polyneuropathy (FAP) for transthyretin (TTR) gene mutations. Thirty-nine families were found to have point mutations causing the following amino acid substitutions: Met30 (28 families), Tyr77 (five), Arg 50 (one), Ala49 (one), Gln89 (one), Ala60 (one) and one each with previously undescribed mutations at Asn35 and Gys54. The clinical picture in the patients with new and known mutations were typical of FAP, without any specific features for a particular mutation. Onset of symptoms was late (over 50 years) in many French and British patients with the Met30 and Tyr77 mutations, and only 30% of all index cases had affected relatives. We propose an approach to molecular diagnosis in European patients with FAP, apart from members of families with known mutations, based on the frequency of TTR mutations observed in this and and other studies of FAP in Europe. It is logical to screen for the Met30 and Tyr77 mutations and Ala60 in the UK, using restriction enzyme analysis. If these are absent, the TTR gene should be sequenced directly to detect less common or unknown mutations.

Adult↗
PubMed1995

A new apolipoprotein Al variant, Trp50Arg, causes hereditary amyloidosis.

A man with hereditary non-neuropathic systemic amyloidosis had amyloid fibril protein subunits consisting of N-terminal fragments (residues 1-86, 1-92 and 1-93) of a previously unknown variant of apolipoprotein Al, Trp50Arg, encoded by a thymine-cytosine transition. This is the third reported amyloidogenic apoAl variant. All involve substitutions of single neutral amino acids by the cationic residue arginine, suggesting a common mechanism of amyloidogenesis. However, the phenotypic expression of these mutations varies both within and between the seven known families with hereditary apoAl amyloidosis. These findings should facilitate analysis of the molecular basis of fibrillogenesis and of factors that modulate amyloid deposition and its consequences in vivo.

Amino Acid Sequence↗
PubMed1994

Isolation of non-LTR retrotransposon reverse transcriptase-like sequences from phlebotomine sandflies.

Reverse transcriptase-like sequences (RTs) with amino acid motifs characteristic of non-LTR retrotransposons have been isolated from several medically important phlebotomine sandfly species. These sequences were amplified using the polymerase chain reaction (PCR) with primers based on conserved amino acid motifs present in previously described insect RTs. A further set of RTs were amplified using primers based on the conserved regions identified in phlebotomine RTs. The average similarity of the phlebotomine RTs to the Drosophila I, F and R1Dm elements was 28-29% between the closest primers used. Phlebotomine RTs were 31-62% similar to each other, the most dissimilar sequences coming from the same species. Several amino acid residues were invariant in the ten phlebotomine RTs, including motif Q(F/Y)GF, conserved in other non-LTR retrotransposons, but not in retrovirus or LTR retrotransposon RTs. The remarkable conservation of this distinctive domain of non-LTR retrotransposon RTs suggests it has a vital and possibly unique role in the mode of reverse transcription of this class of transposon.

Amino Acid Sequence↗
PubMed1994

Familial nephropathic systemic amyloidosis caused by apolipoprotein AI variant Arg26.

A point mutation in the apolipoprotein AI (apoAI) gene causing autosomal dominant non-neuropathic systemic amyloidosis is described in a previously unreported Canadian family of British origin with five affected individuals in three generations. Amyloid deposits in the renal biopsy from the proband, a 31-year-old female presenting with hypertension and renal failure, stained immunospecifically with antiserum to apoAI. The plasma of all family members with amyloidosis contained both wild-type apoAI and a variant bearing one additional positive charge. Sequencing of the apoAI gene demonstrated that the proband was a heterozygote for a single base substitution in exon 3, changing codon 26 from GGC(Gly) to CGC(Arg). Concordance of the mutant allele with the presence of variant plasma apoAI and clinical features of amyloidosis was demonstrated. This is the third family in which this amyloidotic mutation has been described, but the distribution of amyloid deposits and their clinical effects are clearly determined by other genetic and/or environmental factors.

Adult↗
PubMed1993

Human lysozyme gene mutations cause hereditary systemic amyloidosis.

Hereditary non-neuropathic systemic amyloidosis (Ostertag-type) is a rare autosomal dominant disease in which amyloid deposition in the viscera is usually fatal by the fifth decade. In some families it is caused by mutations in the apolipoprotein AI gene but in two unrelated English families under our care the amyloid deposits did not contain apoAI, despite a report that this may have been the case in one of them. Lysozyme is a ubiquitous bacteriolytic enzyme present in external secretions and in polymorphs and macrophages, but its physiological role is not always clear. Here we report that in these two families, lysozyme is the amyloid fibril protein. Affected individuals are heterozygous for point mutations in the lysozyme gene that cause substitution of highly conserved residues, namely threonine for isoleucine at position 56 in one family, and histidine for aspartic acid at residue 67 in the other. Amyloid fibrils from one individual were composed of the full-length Thr-56 variant lysozyme molecule. To our knowledge, this is the first report of naturally occurring variants of human lysozyme and of lysozyme-associated disease. As the structures of human and hen egg-white lysozyme are known to atomic resolution and their folding and structure-function relationships have been exhaustively analysed, our observations should provide a powerful model for understanding amyloidogenesis.

Amino Acid Sequence↗
PubMed1991

DNA probes to identify members of the Anopheles farauti complex.

DNA probes have been constructed to distinguish between the members of the Anopheles farauti complex of mosquitoes known as species numbers 1, 2 and 3. Partial genomic libraries of the three known species were exposed to labelled total genomic DNA from each species. Colonies showing differential hybridization were selected for further testing. These probes were found which allow identification of the three known species: probe pAf1 (160 bp fragment) hybridizes to DNA from An. farauti nos. 1 and 2; probe pAf2 (95 bp fragment) hybridizes to DNA from An. farauti no. 2 only; and probe pAf3 (1.3 kb fragment) hybridizes strongly to DNA from An. farauti no. 3, less to no. 1 and faintly to no. 2. Increasing the stringency of hybridization reduced the cross-hybridization of probes pAf1 and pAf3. Only radioactively labelled probes were tested. Males and females and individuals from diverse habitats and localities showed the same species/probe hybridization characteristics. This technique allows faster identification of the sibling species than previous methods, and has the added advantage that it allows air-dried and alcohol stored specimens to be identified.

Animals↗
PubMed1991

Retrotransposons and evolution in phlebotomines.

The polymerase chain reaction was used to amplify a segment of the reverse transcriptase (RT) gene of putative retrotransposons from Phlebotomus (Larroussius) perniciosus, P. (L.) perfiliewi, P. (Phlebotomus) papatasi and Lutzomyia (Lutzomyia) longipalpis. Based on amino acid sequence comparisons with known RT genes, the amplified products of these species were shown to be derived from non-LTR retrotransposons related to the F element of Drosophila melanogaster. The usefulness of this technique is discussed in relation to taxonomy and genetic manipulation.

Amino Acid Sequence↗
PubMed1990

A relationship found between intra-oral sites of 4NQO reductase activity and chemical carcinogenesis.

Topical application on rat oral mucosa of the chemical 4-nitroquinoline 1-oxide (4NQO) has been shown to produce squamous cell carcinomas on the posterior tongue and/or the posterior hard palate. 4NQO is broken down in vivo by a diaphorase, 4NQO reductase (E.C.1.6.99.2), to produce an active molecule believed to be responsible for carcinogenesis. It has been shown that there are higher concentrations of 4NQO reductase in oesophageal mucosa compared with elsewhere in the gastrointestinal tract. The purpose of these experiments was to compare the distribution of certain diaphorases in the oral mucosa. Samples of rat tongue and cheek epithelia were homogenized, then ultracentrifuged to provide mixed cytosol and microsome fractions from the epithelial cells. A spectrophotometer was used to measure the variation in absorbance at 340 nm of NADH consumed by reduction of 4NQO by enzymes present in the tissue extracts. A histochemical technique was used to compare the activity of NADH diaphorase, NADP diaphorase and glucose-6-phosphate dehydrogenase at different sites of the oral mucosa. Statistical analysis showed that there were significant (P less than 0.01) differences between the activities of all three enzymes at different sites of the oral mucosa. In each case, a higher activity was found at the sites of high incidence of squamous cell carcinoma. A lower activity was found at sites where carcinomas did not occur.

4-Nitroquinoline-1-oxide↗