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Timothy H J Goodship

Publications and source records attributed to Timothy H J Goodship.

27 records · Page 2Linked to original sources
PubMed2003

Disordered calcium crystal handling in antisense CLC-5-treated collecting duct cells.

Dent's disease, an X-linked tubulopathy secondary to defects in chloride channel CLC-5, is characterised by low molecular weight proteinuria, hypercalciuria, nephrocalcinosis, and renal stones. Mechanisms leading to nephrocalcinosis are unknown. Using a murine collecting duct cell line (mIMCD-3), we confirm endogenous expression of mCLC-5. During transfection of antisense CLC-5, we observe a reduction in CLC-5 protein expression that correlates with a reduction in the number of acidic endosomal compartments, as determined by quantitative analysis of confocal microscope images using LysoTracker Red. Using wheat germ agglutinin-lectin as an endocytic marker, an arrest of endocytosis is observed in antisense CLC-5 treated cells. Exposure of the cell surface to calcium oxalate crystals results in crystal agglomeration in a minority of sense CLC-5 transfectants (45%) and all antisense CLC-5 transfectants. We conclude that expression of CLC-5 in mIMCD-3 cells allows acidification of endosomes and endocytosis, and that disruption of CLC-5 expression causes abnormal crystal agglomeration.

Animals↗
PubMed2002

Molecular modelling of the C-terminal domains of factor H of human complement: a correlation between haemolytic uraemic syndrome and a predicted heparin binding site.

Factor H (FH) of the complement system acts as a regulatory cofactor for the factor I-mediated cleavage of C3b and binds to polyanionic substrates. FH is composed of 20 short consensus/complement repeat (SCR) domains. A set of 12 missense mutations in the C-terminal domains between SCR-16 to SCR-20 is associated with haemolytic uraemic syndrome. Recent structural models for intact FH permit the molecular interpretation of these amino acid substitutions. As all nine SCR-20 substitutions correspond to normal amounts of FH in plasma, and were localised in mostly surface-exposed positions, these are inferred to lead to a functional defect in FH. The nine substitutions occur in the same spatial region of SCR-20. As this surface coincides with conserved basic residues in the C-terminal SCR-20 domain, the substitutions provide direct evidence for a polyanionic binding surface. The positions of these conserved basic residues coincide with those of heparin-binding residues in the crystal structure of the acidic fibroblast growth factor-heparin complex. A tenth substitution and another conserved basic residue in SCR-19 are proximate to this binding site. As the remaining FH substitutions could also be correlated with their proximity to conserved basic residues, haemolytic uraemic syndrome may result from a failure of FH to interact with polyanions at cell surfaces in the kidney.

Amino Acid Sequence↗
PubMed2002

Solitary functioning kidney and diverse genital tract malformations associated with hepatocyte nuclear factor-1beta mutations.

BACKGROUND: Renal tract malformations are, on occasion, associated with uterine malformations. The transcription factor hepatocyte nuclear factor (HNF)-1beta is expressed from the earliest stages of development of the Wolffian duct, the mesonephros and metanephros, and the Müllerian ducts in the mouse. In adult mice HNF-1beta is expressed in the kidney tubules, collecting ducts, and in the oviducts and uterus in the female (Müllerian duct derivatives) and in the epididymis, vas deferens and seminal vesicles (Wolffian duct derivatives) in the male. HNF-1beta mutations have been reported in two families where affected members have renal abnormalities, female genital tract malformations and early-onset diabetes. Renal and uterine abnormalities have not been described in families without early-onset diabetes. METHODS: We sequenced the HNF-1beta gene in nine subjects with renal abnormalities and a personal or family history of female genital tract malformations, but no history of diabetes. RESULTS: Two families were identified with novel HNF-1beta mutations: a missense mutation in exon 2 with conversion of serine to proline at codon 151 (S151P) and a frameshift mutation in exon 3 with a 1 base pair deletion at codon 243 (Q243fsdelC). The S151P mutation proband has cystic kidneys and uterus didelphys. Her affected second son has renal cysts and hypospadias. The Q243fsdelC proband has a single functioning kidney and her two children have renal dysplasia. Histology in one child shows cystic dysplasia with a lack of glomeruli. The proband's sister is a mutation carrier and has a bicornuate uterus. Diabetes is not a feature in either family. CONCLUSIONS: This study confirms an association between HNF-1beta mutations and renal and Müllerian anomalies. The hypospadias may be coincidental. This study describes the first HNF-1beta mutations that are associated with a single functioning kidney and the absence of diabetes. This study further reinforces the variability of the renal and non-renal phenotypes associated with HNF-1beta mutations.

Adult↗
PubMed2002

Effects of feeding on albumin synthesis in hypoalbuminemic hemodialysis patients.

BACKGROUND: Hypoalbuminemia is a powerful predictor of morbidity and mortality in hemodialysis (HD) patients and results from a reduction in albumin synthesis. It is not known if this is associated with any impairment of the normal response to feeding. METHODS: Protein turnover and albumin synthesis were measured in the fasting and fed state using a primed constant infusion of L-[1-(13)C]leucine in seven hypoalbuminemic (albumin < or = 36 g/L) HD patients (HHD), seven normoalbuminemic (albumin > or = 40 g/L) HD patients (NHD) and nine age-matched normal controls. RESULTS: The increase in albumin synthesis on feeding was impaired in HHD patients (fasting 15.0 +/- 1.5 vs. fed 17.7 +/- 2.9%, P = NS) compared to NHD (fasting 13.7 +/- 0.9 vs. fed 17.4 +/- 1.0%, P < 0.05) and controls (fasting 12.9 +/- 0.6 vs. fed 15.2 +/- 0.6%, P < 0.05). In addition, body mass index and percent body fat were significantly (P < 0.05) lower in HHD (20.8 +/- 1.3 kg/m2, 23.4 +/- 2.0%) than NHD (26.7 +/- 1.3 kg/m2, 33.1 +/- 3.2%) or controls (26.2 +/- 1.1 kg/m2, 32.6 +/- 1.8%). There was no difference in dietary protein or energy intake in the three groups. CONCLUSIONS: There are differences of body composition and protein metabolism in HHD patients that may be related to an impaired metabolic response to feeding.

Adult↗
PubMed2002

Recurrence of hemolytic uremic syndrome after live related renal transplantation associated with subsequent de novo disease in the donor.

There is a significant risk of disease recurrence in patients with nondiarrheal (D-) hemolytic uremic syndrome (HUS) undergoing renal transplantation. Recent studies have found that approximately 20% of sporadic cases of HUS have mutations in the gene for the complement regulatory protein factor H. The authors report on 2 families, in each of which a family member initially presented with sporadic HUS and subsequently received a live-related renal transplant, one from a sibling and the other from the father. Subsequently, both recipients suffered recurrent HUS in the allograft, and both donors had HUS within a year of the transplant. Neither family has a factor H mutation. This report underlines the risk of disease recurrence in recipients associated with live-related renal transplantation in HUS and also suggests that the donors may be at risk.

Adult↗
PubMed2002

The genetics and pathogenesis of haemolytic uraemic syndrome and thrombotic thrombocytopenic purpura.

PURPOSE OF REVIEW: In recent years there has been a substantial increase in the understanding of the genetics and pathogenesis of haemolytic uraemic syndrome and thrombotic thrombocytopenic purpura. RECENT FINDINGS: In diarrhoeal associated haemolytic uraemic syndrome it has been established that the virulence of Escherichia coli O157 is related to intimin adhesion and the transport of verocytotoxin on polymorphonuclear cells. It has been shown that early changes in the coagulation pathway predate the onset of diarrhoeal haemolytic uraemic syndrome. Mutations in factor H, a fluid-phase regulator of the alternative complement pathway, have been identified in 10-20% of patients with both familial and sporadic (non-diarrhoeal-associated) haemolytic uraemic syndrome. The mutations mainly cluster in the C terminal part of factor H, a region that is important for both binding to C3b and also polyanionic structures on cell surfaces. The identification of antibodies against a plasma metalloproteinase responsible for cleaving ultralarge von Willebrand factor multimers in thrombotic thrombocytopenic purpura has been followed by the elucidation of the identity of the proteinase. It has been shown to be a member of the ADAMTS family, and mutations have been identified in the gene in families with inherited thrombotic thrombocytopenic purpura. SUMMARY: The molecular pathogenesis of haemolytic uraemic syndrome and thrombotic thrombocytopenic purpura is an exciting and rapidly evolving field. These recent advances will lead to logical, targetted changes in the management of these conditions.

Diarrhea↗
PubMed2002

Skeletal muscle mRNA levels for cathepsin B, but not components of the ubiquitin-proteasome pathway, are increased in patients with lung cancer referred for thoracotomy.

Muscle wasting is a common and prominent feature of advanced cancer, including lung cancer. Evidence from animal experiments suggests that accelerated proteolysis via the ubiquitin--proteasome pathway is the primary cause of cancer-related cachexia. However, there are few data on the role of this pathway in determining muscle wasting in human cancer. The present study was designed to measure whether skeletal muscle gene expression of components of the ubiquitin-proteasome pathway and/or the lysosomal proteolytic pathway was increased in patients with early lung cancer. A total of 36 patients with lung cancer referred for curative resection and 10 control subjects had biopsies of latissimus dorsi muscle taken at operation. mRNA levels of four components of the ubiquitin-proteasome pathway, i.e. polyubiquitin, C2 alpha proteasome subunit, 14 kDa ubiquitin-carrier protein and ubiquitin-activating protein, and of two lysosomal proteolytic enzymes, i.e. cathepsin B and cathepsin D, were measured using quantitative Northern blotting. mRNA levels for cathepsin B, but not for components of the ubiquitin--proteasome pathway, were higher in patients with cancer compared with controls (P=0.01). Among lung cancer patients, cathepsin B mRNA levels correlated with fat-free mass index (r = -0.57, P=0.003) and tumour stage (r(s)=0.45, P=0.03), and were higher in smokers (P=0.04). Thus gene expression of the lysosomal protease cathepsin B is increased in the skeletal muscle of patients with early lung cancer, and the strong inverse relationship with fat-free mass suggests that cathepsin B may have a role in inducing muscle wasting in the early stages of lung cancer.

Aged↗