PubMed Health⌕ Search

Biomedical subjects

S Jeffery

Publications and source records attributed to S Jeffery.

At least 19 recordsLinked to original sources
PubMed2006

The natural history of Noonan syndrome: a long-term follow-up study.

OBJECTIVE: To define better the adult phenotype and natural history of Noonan syndrome. DESIGN: A prospective observational study of a large cohort. RESULTS: Data are presented for 112 individuals with Noonan syndrome (mean age 25.3 (range 12-71) years), who were followed up for a mean of 12.02 years. Mutations in PTPN11 were identified in 35% of probands. Ten subjects died during the study interval; three of these deaths were secondary to heart failure associated with hypertrophic cardiomyopathy. Pulmonary stenosis affected 73 (65%) subjects; 42 (58%) required no intervention, nine underwent balloon pulmonary valvuloplasty (three requiring further intervention) and 22 surgical valvuloplasty (three requiring further intervention). Hypertrophic cardiomyopathy affected 21 (19%) patients, which had remitted in two cases, but one subject required cardiac transplant. No subjects died suddenly or had symptoms suggestive of arrhythmia. The mean final adult height was 167.4 cm in males and 152.7 cm in females. Feeding problems in infancy were identified as a predictor of future outcome. The mean age of speaking in two-word phrases was 26 months for those with no feeding difficulties, compared with 39 months for those with severe problems requiring nasogastric feeding. Attendance at a school for children with special needs for the same groups was 12.5% and 58%, respectively. A statement of special educational need had been issued in 44% overall; however, academic achievement was broadly similar to that of the general population. IMPLICATIONS: Although the morbidity for some patients with Noonan syndrome is low, early predictors of poorer outcome have been identified, which will help ascertain those most in need of intervention.

Abnormalities, Multiple↗
PubMed2005

Linkage to the FOXC2 region of chromosome 16 for varicose veins in otherwise healthy, unselected sibling pairs.

BACKGROUND: The FOXC2 gene on 16q24 is mutated in lymphoedema distichiasis (LD), in which varicose veins (VV) are a common feature. We hypothesised that this gene might be implicated in the development of VV in the normal population, therefore, after performing a classical twin study, we tested for linkage and association in white women. We also tested for linkage with haemorrhoids (H), as a separate venous anomaly at the same locus. METHODS: A total of 2060 complete female twin pairs aged 18-80 years from the St Thomas' Adult UK Twin registry replied to questions on VV and H as part of a broader postal survey of 6600 twins (62% response rate). Dizygotic female twin pairs were tested for linkage and association to the candidate marker D16S520 (1903 individuals genotyped), which is located about 80 kb from FOXC2. RESULTS: Casewise concordance rates were significantly higher for monozygotic than dizygotic twins for both phenotypes (VV 67% v 45%; p = 2.2x10(-6); H 68% v 59%; p = 0.01; H including during pregnancy 73% v 64%; p = 2.1x10(-4)), corresponding to additive genetic heritabilities in liability of 86% (95% confidence interval (CI) 73% to 99%) for VV and 56-61% for H (95% CI 43% to 73%). The presence of VV and H were significantly correlated. We found significant evidence of linkage to the marker for VV (MLS(ASP) = 1.37, p = 0.01; GLM(ASP/DSP) Z = 3.17 p = 0.002), but no association. Both linkage and association tests were negative for H. The combined phenotype of having VV and H did not show any evidence of linkage or association. CONCLUSION: These results demonstrate VV and H to be heritable, related conditions, and the data strongly suggest FOXC2 to be implicated in the development of VV in the general population.

Adolescent↗
PubMed2005

Milroy disease and the VEGFR-3 mutation phenotype.

Primary congenital lymphoedema (Milroy disease) is a rare autosomal dominant condition for which a major causative gene defect has recently been determined. Mutations in the vascular endothelial growth factor receptor 3 (VEGFR-3) gene have now been described in 13 families world-wide. This is a review of the condition based on the clinical findings in 71 subjects from 10 families. All 71 individuals have a mutation in VEGFR-3. Ninety per cent of the 71 individuals carrying a VEGFR-3 mutation showed signs of oedema, which was confined in all cases to the lower limbs. In all but two cases onset of swelling was from birth. Other symptoms and signs included cellulitis (20%), large calibre leg veins (23%), papillomatosis (10%), and upslanting toenails (10%). In males, hydrocoele was the next most common finding after oedema (37%). Thorough clinical examination of these patients indicates that there are few clinical signs in addition to lower limb oedema. Rigorous phenotyping of patients produces a high yield of VEGFR-3 mutations.

Adult↗
PubMed2004

CD14 and toll-like receptor 4: a link between infection and acute coronary events?

The CD14 receptor is a pattern recognition molecule in the innate immune response against microorganisms and other exogenous and endogenous stress factors. The most important CD14 signalling co-receptor is toll-like receptor 4 (TLR4), which activates, among others, the nuclear factor kappaB (NF-kappaB) inflammatory pathway. Besides its role in innate immunity and host defence, the proinflammatory cytokines expressed upon TLR4/NF-kappaB pathway activation exert proatherogenic effects. The CD14 C(-260)T promoter and TLR4 Asp299Gly functional polymorphisms have been recently implicated in the development of cardiovascular events, suggesting that the genetically determined inflammatory response against pathogens or their antigens may have a major role in atherogenesis and subsequent acute events. Is the association of these polymorphisms with cardiovascular disease more evidence for the implication of infection, especially by Gram negative bacteria, in the development of acute coronary events? This article reviews the molecular basis, biological functions, and clinical implications of the CD14/TLR4 polymorphisms in the development of cardiovascular events.

Cell Communication↗
PubMed2002

Are cysteinyl leukotrienes involved in allergic responses in human skin?

BACKGROUND: Cysteinyl leukotrienes have been suggested to be involved in producing the symptoms of both the early and late phases of the allergic response in the lung and other tissues. OBJECTIVE: To use scanning laser Doppler imaging, microdialysis and immunocytochemistry to explore the mediator and cellular mechanisms of the dermal allergic response. METHODS: Thirteen atopic volunteers received intradermal injections into the forearm of grass pollen or D. pteronyssinus extract. Changes in dermal blood flow up to 8 h were monitored by scanning laser Doppler imaging. The release of histamine, PGD2 and LTC4/D4/E4 was assessed by dermal microdialysis. Skin biopsies were taken at 6 h to determine numbers of mast cells, eosinophils, basophils, Langerhans' cells, and monocytes/macrophages, and the expression of COX-1, COX-2, 5-LO and FLAP. RESULTS: Allergen provocation produced an immediate weal and flare response followed by an erythematous induration peaking at 6 h. During the first hour, c. 84 pmoles of histamine and c. 0.3 pmoles of PGD2 were recovered by microdialysis (both P < 0.001) but LTC4/D4/E4 was undetectable. No histamine, PGD2 or LTC4/D4/E4 was detectable at later times. Immunocytochemical examination of biopsies taken at 8 h showed increased numbers of eosinophils and basophils and in COX-2, 5-LO and FLAP, but not COX-1. Expression of 5-LO and FLAP was associated primarily with eosinophils. CONCLUSIONS: These findings suggest that inflammatory cells recruited to the site of allergen injection are not activated to release detectable amounts of cysteinyl leukotrienes. Hence, it is unlikely that the late-phase erythematous induration is mediated by this autocoid.

5-Lipoxygenase-Activating Proteins↗
PubMed2002

T594M mutation of the beta-subunit of the epithelial sodium channel in Ghanaian populations from Kumasi and London and a possible association with hypertension.

We have tested 186 individuals from Ghana, 95 indigenous and 91 who have settled in the United Kingdom, for the presence of the T594M mutation in the beta-subunit of the epithelial sodium channel, which is associated with hypertension in black populations. The group living in Ghana had a mean age of 27 years and were normotensive, but had an increased frequency of the T allele compared to the London-based population. If this is reflected in larger studies, and the link with hypertension is maintained in the Ghanaian population, this mutation could be a significant cause of hypertension in Ghana.

Adult↗
PubMed2002

Analysis of the phenotypic abnormalities in lymphoedema-distichiasis syndrome in 74 patients with FOXC2 mutations or linkage to 16q24.

INTRODUCTION: Lymphoedema-distichiasis syndrome (LD) (OMIM 153400) is a rare, primary lymphoedema of pubertal onset, associated with distichiasis. Causative mutations have now been described in FOXC2, a forkhead transcription factor gene. Numerous clinical associations have been reported with this condition, including congenital heart disease, ptosis, varicose veins, cleft palate, and spinal extradural cysts. SUBJECTS: We report clinical findings in 74 affected subjects from 18 families and six isolated cases. All of them were shown to have mutations in FOXC2 with the exception of one family who had two affected subjects with lymphoedema and distichiasis and linkage consistent with the 16q24 locus. RESULTS: The presence of lymphoedema was highly penetrant. Males had an earlier onset of lymphoedema and a significantly increased risk of complications. Lymphatic imaging confirmed the earlier suggestion that LD is associated with a normal or increased number of lymphatic vessels rather than the hypoplasia or aplasia seen in other forms of primary lymphoedema. Distichiasis was 94.2% penetrant, but not always symptomatic. Associated findings included ptosis (31%), congenital heart disease (6.8%), and cleft palate (4%). Other than distichiasis, the most commonly occurring anomaly was varicose veins of early onset (49%). This has not been previously reported and suggests a possible developmental role for FOXC2 in both venous and lymphatic systems. This is the first gene that has been implicated in the aetiology of varicose veins. CONCLUSION: Unlike previous publications, the thorough clinical characterisation of our patients permits more accurate prediction of various phenotypic abnormalities likely to manifest in subjects with FOXC2 mutations.

Abnormalities, Multiple↗
PubMed2001

Intermediate care. Homeward bound.

Establishing a community acute and rehabilitation team for stroke patients has reduced the length of acute inpatient stay from 23 to eight days, without adversely affecting outcomes. The numbers of GPs referring directly to the community stroke team exceeded expectations (37 per cent of all referrals), avoiding accident and emergency admissions. Establishing good inter-agency agreements was crucial to the success of the project.

Continuity of Patient Care↗
PubMed2001

Energy dissipation in atomic force microscopy and atomic loss processes.

Atomic scale dissipation is of great interest in nanomechanics and atomic manipulation. We present dissipation measurements with a linearized, ultra-small amplitude atomic force microscope which is capable of measuring dissipation at chosen, fixed separations. We show that the dynamic dissipation in the noncontact regime is of the order of a few 10-100 meV per cycle. This dissipation is likely due to the motion of a bistable atomic defect in the tip-surface region. In the contact regime we observe dc hysteresis associated with nanoscale plasticity. We find the hysteretic energy loss to be 1 order of magnitude higher for a silicon surface than for copper.

Journal Article↗
PubMed2001

Silver syndrome is not linked to any of the previously established autosomal dominant hereditary spastic paraplegia loci.

The hereditary spastic paraplegias are a clinically variable and genetically heterogeneous group of disorders characterized by progressive and lower limb spasticity and weakness. Silver syndrome (SS) is a particularly disabling autosomal dominant form of the disease in which there is associated wasting of the hand muscles. In view of the fact that genes for hereditary spastic paraplegia can produce highly variable phenotypes, the eight known autosomal dominant loci were investigated for linkage to Silver syndrome. Genotyping of these loci in two large multigenerational families was incompatible with linkage to any of these regions, suggesting that an additional locus is responsible for this syndrome.

Adult↗
PubMed2001

The Silver syndrome variant of hereditary spastic paraplegia maps to chromosome 11q12-q14, with evidence for genetic heterogeneity within this subtype.

The hereditary spastic paraplegias (HSPs) are a complex group of neurodegenerative disorders characterized by lower-limb spasticity and weakness. Silver syndrome (SS) is a particularly disabling dominantly inherited form of HSP, complicated by amyotrophy of the hand muscles. Having excluded the multiple known HSP loci, we undertook a genomewide screen for linkage of SS in one large multigenerational family, which revealed evidence for linkage of the SS locus, which we have designated "SPG17," to chromosome 11q12-q14. Haplotype construction and analysis of recombination events permitted the minimal interval defining SPG17 to be refined to approximately 13 cM, flanked by markers D11S1765 and D11S4136. SS in a second family was not linked to SPG17, demonstrating further genetic heterogeneity in HSP, even within this clinically distinct subtype.

Adolescent↗
PubMed2001

Decreased wild-type full-length Et-A and -B receptors in neuroblastoma and Ewing sarcoma cells.

BACKGROUND: Endothelins and their receptors, Et-A and Et-B, play an essential role in differentiation and migration of neural crest cells. Expression of endothelin receptors has been examined in neuroblastoma and Ewing sarcoma cell lines. PROCEDURE: RNA was amplified for Et-A and Et-B by RT-PCR. Amplified products were cloned into the expression vector pLNCX, which was used to transfect CHO cells. Binding characteristics of transfected CHO cells were examined. RESULTS: Full-length Et-A mRNA was identified in all cell lines, in addition to a truncated Et-A product. CHO cells expressing full-length Et-A bound to endothelin, but cells expressing truncated Et-A did not. Full length Et-B mRNA was not detected, but two smaller molecular weight products were amplified. These are as yet uncharacterised. CONCLUSIONS: These results suggest that endothelins and their receptors may be important in the development and biology of neuroblastoma and Ewing sarcoma.

Animals↗
PubMed2001

Analysis of lymphoedema-distichiasis families for FOXC2 mutations reveals small insertions and deletions throughout the gene.

Lymphoedema-distichiasis (LD) is a dominantly inherited form of primary lymphoedema with onset of lower limb swelling at puberty or later. There is variable penetrance of this disorder, but the most consistently inherited feature is distichiasis, viz. fine hairs arising inappropriately from the meibomian glands. We established linkage of this disorder to 16q24.3 and the gene has recently been identified as the forkhead transcription factor FOXC2. We report the mutational analysis of 14 families with LD. All but one of these pedigrees have small insertions or deletions in the gene, which seem likely to produce haploinsufficiency. The mutation sites are scattered throughout the gene. There is one family with a mis-sense mutation in the forkhead domain of the protein. This base alteration is not a common polymorphism, is co-inherited with the disease and produces a non-conservative amino acid change.

DNA↗
PubMed2001

Mutations in PTPN11, encoding the protein tyrosine phosphatase SHP-2, cause Noonan syndrome.

Noonan syndrome (MIM 163950) is an autosomal dominant disorder characterized by dysmorphic facial features, proportionate short stature and heart disease (most commonly pulmonic stenosis and hypertrophic cardiomyopathy). Webbed neck, chest deformity, cryptorchidism, mental retardation and bleeding diatheses also are frequently associated with this disease. This syndrome is relatively common, with an estimated incidence of 1 in 1,000-2,500 live births. It has been mapped to a 5-cM region (NS1) [corrected] on chromosome 12q24.1, and genetic heterogeneity has also been documented. Here we show that missense mutations in PTPN11 (MIM 176876)-a gene encoding the nonreceptor protein tyrosine phosphatase SHP-2, which contains two Src homology 2 (SH2) domains-cause Noonan syndrome and account for more than 50% of the cases that we examined. All PTPN11 missense mutations cluster in interacting portions of the amino N-SH2 domain and the phosphotyrosine phosphatase domains, which are involved in switching the protein between its inactive and active conformations. An energetics-based structural analysis of two N-SH2 mutants indicates that in these mutants there may be a significant shift of the equilibrium favoring the active conformation. This implies that they are gain-of-function changes and that the pathogenesis of Noonan syndrome arises from excessive SHP-2 activity.

Chromosomes, Human, Pair 12↗