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Biomedical subjects

T G Feest

Publications and source records attributed to T G Feest.

At least 19 recordsLinked to original sources

Apolipoprotein AI mutation Arg-60 causes autosomal dominant amyloidosis.

A mutation in the gene for apolipoprotein AI (apoAI) was identified in an English family with autosomal dominant non-neuropathic systemic amyloidosis. The plasma of all affected individuals contained a variant apoAI with one additional charge, as well as normal apoAI. The propositus was heterozygous; the coding region of his apoAI gene contained both the normal sequence and a single-base substitution changing the codon for residue 60 of the mature protein from CTG (leucine) to CGG (arginine). Allele-specific oligonucleotide hybridization showed that the other affected individuals were also heterozygotes and that there was concordance of the mutant allele with the presence of variant plasma apoAI. Amyloid fibrils isolated from the spleen of the propositus consisted of proteins that ran as a doublet with an apparent mass of approximately 10 kDa in SDS/PAGE and a trace band at 28 kDa. Electrospray mass spectrometry of the purified 10-kDa material revealed components with mass corresponding to the N-terminal 88, 92, 93, and 94 residues of apoAI each with substitution of arginine for leucine. These observations were confirmed by direct protein sequencing and laser desorption time-of-flight mass analysis. No material with the normal apoAI sequence was detected. The trace band at 28 kDa yielded the N-terminal sequence of mature apoAI, indicating that intact or minimally degraded apoAI was also present in the fibril preparation. Discovery of this mutation and the detailed characterization of the apoAI fragments that form the amyloid fibrils open additional avenues for investigation of amyloidogenesis.

Amino Acid Sequence

Incidence of advanced chronic renal failure and the need for end stage renal replacement treatment.

OBJECTIVE: To determine the age related incidence of advanced chronic renal failure in two areas of England. DESIGN: Prospective study of patients newly identified as having advanced chronic renal failure within a two year period; subsequent monitoring of patients' clinical course for a further 26 months. SETTING: Devon and Blackburn. SUBJECTS: Those patients in a population of 708,997 who developed advanced chronic renal failure (serum creatinine concentration greater than 500 mumol/l) for the first time during a two year period. MAIN OUTCOME MEASURES AND RESULTS: 210 Patients (148 per million population per year) developed advanced chronic renal failure, 117 (51%) of whom were over 70. The age related incidence rose from 58 per million per year in those aged 20-49 to 588 per million per year in those aged 80 or over. Only 54% (113) of patients were referred to a nephrologist; 120 patients (57%) needed dialysis or died within three months of presenting without receiving dialysis, and 187 (89%) died or needed dialysis within three years. After those unsuitable for further treatment had been excluded, 78 patients per million population per year aged under 80 needed to start long term renal replacement treatment. CONCLUSIONS: Many patients suitable for renal replacement treatment are still not referred for nephrological opinion and are denied treatment. If the treatment rate in the United Kingdom rose from the 1988 rate of 55.1 per million per year to 78 per million per year then the number of patients receiving treatment would rise to about 800 per million. This is double the present number and has considerable but predictable resource implications for the NHS.

Adolescent

Protocol for increasing organ donation after cerebrovascular deaths in a district general hospital.

In a district general hospital serving 303,000 people, deaths from cerebrovascular incidents over 12 months were analysed retrospectively. 8 patients who died in general wards were identified as potential organ donors. A working party then devised a protocol for managing such donors by transfer to the intensive care unit for support until organ retrieval could be arranged. In the first 19 months with the protocol, organs (1 heart, 2 sets of heart valves, 2 livers, and 16 kidneys) were retrieved from 8 patients who would not otherwise have become donors. If these results were replicated nationally a further 16.7 donors per million per year would be added to the current annual UK rate of 14.6 donors per million.

Adult

Osteomalacic dialysis osteodystrophy: Evidence for a water-borne aetiological agent, probably aluminium.

In patients maintained on regular haemodialysis in Newcastle upon Tyne the development of osteomalacia is substantially reduced when water used to prepare dialysate is deionised. After 1--4 years of dialysis, osteomalacia was evident in 15% of patients on deionised water in 70% of patients on softened water from the same source. The close association of dialysis encephalopathy and osteomalacia suggests a common aetiology. Both diseases occur in centres with a high tap-water aluminium content. Serum-aluminium concentrations were raised in patients undergoing regular haemodialysis in the Northern Region of England. Those using softened water had higher concentrations than those using deionised water. Patients on softened water who had encephalopathy or dementia had serum-aluminium concentrations similar to those of patients using the same water-supplies without symptoms of these diseases, but they had been treated for longer. The evidence that aluminium absorption from dialysate causes osteomalacia and encephalopathy is strong enough to justify the expense of treating water by deionisation, reverse osmosis, or both in centres where tap-water aluminium is high.

Adolescent

Osteomalacic dialysis osteodystrophy: a trial of phosphate-enriched dialysis fluid.

To assess whether phosphate depletion is an aetiological factor in osteomalacic dialysis osteodystrophy we undertook a prospective trial of phosphate-enriched dialysis fluid, in association with oral 1alpha-hydroxycholecalciferol, for this condition. Thirty patients started the trial; of the 27 who completed more than 6 months' treatment, 14 had iliac crest bone biopsies at the beginning and end of the treatment period. Side effects included pruritus, stiffness, and increase in corneal and vascular calcification. Only one patient showed histological improvement of osteomalacia, and eight deteriorated; in seven the osteitis fibrosa worsened. Myopathy showed some improvement in four patients, but became worse in four. This treatment does not seem to have a place in the routine management of non-hypophosphataemic patients on dialysis.

Adolescent

Hemodialysis bone disease: correlation between clinical, histologic, and other findings.

This paper explores in patients with dialysis osteodystrophy the relationship between clinical features and histological, radiological, and biochemical findings. Eighty-five patients treated by hemodialysis for more than 6 months were studied. The following conclusions were drawn: 1) Bone pain in patients on regular hemodialysis is usually a symptom of developing osteomalacia but not of hyperparathyroidism or osteoporosis. 2) Many patients with histological osteomalacia and radiological features of osteomalacia, such as fractures or Looser zones, have no symptoms. 3)In dialysis patients, biochemical and radiological abnormalities are not a reliable means of predicting the presence of osteomalacia, but a raised serum alkaline phosphatase is a good indicator of the presence of osteitis fibrosa. For early detection of osteomalacia, bone biopsy in necessary. 4)A number of our dialysis patients develop an unusual form of osteomalacia characterized by absent or minimal histological osteitis fibrosa, a normal serum alkaline phosphatase, and a high incidence of myopathy and fractures.

Adolescent

Renal histology and immunopathology in distal renal tubular acidosis.

Renal biospy studies are reported from 10 patients with distal renal tubular acidosis (DRTA). On the biopsies from 6 patients who had associated immunological abnormalities immunofluorescent studies for immunoglobulins, complement, and fibrin were performed. Interstitial cellular infiltration and fibrosis were common findings in patients with and without immunological abnormalities, and were usually associated with nephrocalcinosis and/or recurrent urinary infection. No immune deposits were demonstrated in association with the renal tubules. This study shows that DRTA in immunologically abnormal patients is not caused by tubular deposition of antibody or immune complexes. The possibility of cell mediated immune damage is discussed.

Acidosis, Renal Tubular

Serum ferritin concentration: a reliable guide to iron overload in uremic and hemodialyzed patients.

The inter-relationships between serum ferritin, hemoglobin, serum iron and total body iron stores were studied in 20 patients with chronic renal failure treated conservatively and in 20 patients on regular hemodialysis. There was no relationship between serum iron or transferrin and bone marrow iron deposits, but serum ferritin concentration was a good indicator of increased marrow iron stores. All patients with serum ferritin levels above 300 microgram/l had increased iron stores. Serum ferritin assay is a useful non-invasive technique for detecting iron overload in uremic and hemodialyzed patients.

Adolescent

Haemodialysis-induced leucopenia and activation of complement: effects of different membranes.

The effects on neutrophil count and complement activity of five different haemodialysis membranes were studied. There was no correlation between the degree of neutropenia and intensity of complement activation. With cuprophan membrane both occurred simultaneously but to unrelated degrees; polyacronitrile induced mild, not significant neutropenia but marked activation of complement; polycarbonate membranes induced severe neutropenia without detectable complement activation. Where complement activation occurred it was via the alternative pathway. Haemodialysis induced neutropenia may have many causes and complement activation is probably not the major responsible factor.

Acrylic Resins