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Biomedical subjects

F G Hill

Publications and source records attributed to F G Hill.

At least 19 recordsLinked to original sources

The usefulness of bone marrow aspiration in the diagnosis of Niemann-Pick disease type C in infantile liver disease.

BACKGROUND: Niemann-Pick disease type C (NPC) is a fatal, autosomal recessive lysosomal storage disease which may present in infancy with cholestatic jaundice and/or hepatosplenomegaly. In cholestatic patients with splenomegaly, a bone marrow aspirate has been advocated as a relatively accessible tissue to demonstrate storage phenomena. Typically in patients with NPC, macrophages with abnormal cholesterol storage, so called foam cells, can be detected in the bone marrow. AIM: To review our experience of bone marrow aspiration in children with NPC presenting with infantile liver disease. METHODS: A retrospective analysis of 11 consecutive children (8 males) from Birmingham Children's Hospital with NPC presenting with infantile liver disease was undertaken. The diagnosis of NPC was confirmed in all cases by demonstrating undetectable or low rates of cholesterol esterification and positive filipin staining for free cholesterol in cultured fibroblasts. RESULTS: The median age at presentation was 1.5 months (range 0.5-10). Bone marrow aspirates showed storage cells in only 7/11 cases. Bone marrow aspirates which had storage cells were undertaken at a median age of 11 months while those with no storage cells were undertaken at median age 2.3 months. The overall sensitivity of bone marrow aspirates for detecting storage cells in children presenting with infantile liver disease was 64%; however, for children who had bone marrow aspirates in the first year of life it was only 57%. CONCLUSIONS: The sensitivity of bone marrow aspirate for the diagnosis of NPC disease in patients presenting with infantile liver disease was lower than previously reported. Where NPC is suspected clinically, definitive investigations should be undertaken promptly. There is a need to develop sensitive screening methods for NPC in children presenting with infantile liver disease.

Age Factors↗

Aberrant dimerization of von Willebrand factor as the result of mutations in the carboxy-terminal region: identification of 3 mutations in members of 3 different families with type 2A (phenotype IID) von Willebrand disease.

The 3' end of the VWF gene was screened in the affected members of 3 different families with type 2A (phenotype IID) von Willebrand disease (vWD). Exons 49 to 52 of the VWF gene were amplified and screened for mutations by chemical cleavage mismatch detection. Mismatched bands were detected in exon 52 of 2 patients and in exon 51 of a third patient. Using direct DNA sequencing, a heterozygous G8562A transition leading to a Cys2008Tyr substitution was found in all the patients in family 1, and a T8561A transversion leading to a Cys2008Ser substitution was found in both patients from family 2. In a patient from a third family, an 8-base deletion from nucleotide 8437 to 8444 was identified in exon 51. The 2 mutations in exon 52 were reproduced by in vitro site-directed mutagenesis of full-length von Willebrand factor (vWF) cDNA and transiently expressed in COS-7 cells. The corresponding recombinant VWFs for these 2 mutations exhibited the typical aberrant vWF:Ag multimer pattern seen in the plasma of the patients. These 3 mutations demonstrate the importance of other carboxy-terminal cysteines in addition to the reported Cys2010 residue, in the normal dimerization of vWF, and their essential role in the assembly of normal multimeric vWF. (Blood. 2001;98:674-680)

Animals↗

Progressive reduction in treatment-related deaths in Medical Research Council childhood lymphoblastic leukaemia trials from 1980 to 1997 (UKALL VIII, X and XI).

In the last 20 years, the survival rate for children with acute lymphoblastic leukaemia (ALL) has markedly improved, largely owing to a decrease in relapses. However, children still die from complications of treatment and these are potentially preventable. We have analysed data from three large consecutive national protocols for ALL from 1980 to 1997 [Medical Research Council United Kingdom ALL (MRC UKALL) trials VIII, X and XI] to compare the incidence and causes of treatment-related deaths (TRD). The percentage of TRD has fallen from 9% to 2% (UKALL VIII to XI), largely as a result of a decrease in fatal infections. Deaths during induction have fallen from 3% to 1%, the main causes of death being bacterial, followed by fungal infection, while other causes, chiefly haemorrhage, have not declined. Remission deaths also decreased from 6% to 1%, particularly those deaths due to measles and pneumocystis carinii. More guidelines for surveillance and treatment of infections have been included within progressively more intensive protocols. Risk factor analysis showed increased TRD in patients with Down's syndrome, high leucocyte count and older age in UKALL XI. In contrast, the introduction of blocks of intensification was not associated with an increased death rate. While improved supportive care has reduced the incidence of TRD, there is still scope for further reduction by prompt treatment of suspected infection. Maintenance of herd immunity remains of vital importance in avoiding deaths from measles.

Antineoplastic Agents↗

Site and type of mutations in the factor VIII gene in patients and carriers of haemophilia A.

Haemophilia A is an X-linked bleeding disorder caused by reduced or absent FVIII (FVIII) protein caused by mutations in the FVIII gene. We have used Southern blotting and chemical mismatch analysis (CMA) to identify the mutations causing haemophilia A in 59 local or referred patients or carriers of haemophilia A. Southern blot analysis of 87 families with FVIII : C < 5% identified 31 as positive for the intron 22 inversion. Analysis of 19 of the inversion-negative families and a further nine families with mild or moderate haemophilia A by CMA resulted in the identification of a heterogeneous spectrum of mutations in the FVIII gene comprising 21 single base-pair substitutions and nine deletions. Seventeen of the base-pair substitutions are missense, two nonsense, and two are splice-site mutations. Two patients were found to have compound mutations with two mutations identified on a single X chromosome. Six of the point mutations and six of the deletions have not been reported previously in the haemophilia A mutation database. Unusually, a missense mutation, as well as deletion and splice-site mutations, was found to be associated with exon-skipping events.

Factor VIII↗

Down's syndrome and acute lymphoblastic leukaemia: clinical features and response to treatment.

AIMS: To examine the clinical and biological features of acute lymphoblastic leukaemia in children with Down's syndrome (DS), to compare their survival with other children, and to determine if entry to trials and survival has improved. METHODS: Examination of presenting features and response to treatment in patients treated in two consecutive national trials, MRC UKALL X and XI. RESULTS: The proportion of children with DS was significantly higher in UKALL XI (1.9%) than UKALL X (0.9%). Children with DS tended to be under 10 years and to have the common ALL subtype. Cytogenetic analysis showed that favourable features, such as high hyperdiploidy and t(12;21) were less frequent but also that there was a lack of translocations associated with a poor prognosis. Children with DS showed no increase in risk of relapse at any site but their survival and event free survival were inferior to other children. These results were caused by an increased number of infective deaths during remission (11% compared to 2%). At five years overall survival was 73% in DS children compared with 82% in other children; event free survival was 53% compared to 63% in non-DS children. CONCLUSIONS: Entry of children with DS to national trials has increased and survival has improved. However they remain at risk of relapse and also of treatment related mortality. These findings emphasise the need for both intensive chemotherapy and optimal supportive care.

Child↗

Bone marrow transplantation versus chemotherapy in the treatment of very high-risk childhood acute lymphoblastic leukemia in first remission: results from Medical Research Council UKALL X and XI.

The role of bone marrow transplantation (BMT) in first remission of children with high-risk acute lymphoblastic leukemia (ALL) remains unclear. There were 3676 patients (aged 1 to 15 years) entered into the United Kingdom (UK) Medical Research Council (MRC) trials UKALL X and XI from 1985 to 1997. Of these patients, 473 patients (13%) were classified as very high (VH) risk and were eligible for a transplantation from a matched histocompatible sibling donor (MSD). We tissue-typed 286 patients; 99 patients had a matched related donor, and 76 patients received transplantations. Additionally, 25 children received transplantations from a matched unrelated donor (MUD) despite trial guidelines for MSD transplantations only. The median time to transplantation was 5 months (range, 2 to 19 months), and the median follow-up was 8 years. The 10-year event-free survival (EFS) adjusted for the time to transplantation, diagnostic white blood cell (WBC) count, Ph chromosome status, and ploidy was 6. 0% higher (95% confidence interval (CI), -10.5% to 22.5%) for 101 patients who received a first-remission transplantation (MSD and MUD) than for the 351 patients treated with chemotherapy (transplantation, 45.3%, vs chemotherapy, 39.3%). The transplantation group had fewer relapses (31%) compared to relapses in the chemotherapy group (55%); however, the transplantation group had more remission deaths (18%) compared to remission deaths in the chemotherapy group (3%). In contrast the adjusted 10-year EFS was 10. 7% higher (95% CI, -2.6% to 24.0%) for patients without a human leukocyte antigen (HLA)-matched donor than for those patients with a donor (no donor, 50.4%, vs donor, 39.7%). In conclusion, for the majority of children with VH-risk ALL, the first-remission transplantation has not improved EFS.

Adolescent↗

Long-term follow-up of the United Kingdom Medical Research Council protocols for childhood acute lymphoblastic leukaemia, 1980-1997. Medical Research Council Childhood Leukaemia Working Party.

Results of three consecutive completed UK trials (1980-1997) for childhood lymphoblastic leukaemia are presented. National accrual has progressively increased so that over 90% of all the country's ALL cases were treated on the latest trial reported, UKALLXI. From 1980 to 1990, event-free and overall survival progressively improved, following adoption of an American therapy template and use of two post-remission intensification modules. Since 1990 despite demonstration of the benefit of a third intensification module overall event-free survival (EFS) has not improved further. Survival remains high due to a good retrieval rate especially for those relapsing off treatment after receipt of two intensification pulses. Possible reasons for the plateau in event-free survival (including type and dose of induction steroid, dropping of induction anthracycline, type and dose of asparaginase, gaps early in therapy following intensification, and overall lack of compliance in maintenance) are being explored in the latest protocol ALL '97. Cranial irradiation had been successfully replaced by a long course of intrathecal methotrexate injections for the majority of patients. Age (<1 year >10 years) sex (male) and white count >50 x 10(9)/l plus slow initial bone marrow clearance were consistently the most important independent prognostic indicators during this time period. Rome/NCI criteria accurately predict standard and high-risk groups for B cell lineage, but not consistently for T cell disease. This international collaborative venture might help us to define those truly at highest risk, and how we can optimise therapy for specific subgroups including T-ALL and those with unfavourable cytogenetics.

Antineoplastic Combined Chemotherapy Protocols↗

A new candidate missense mutation (Leu 1657 IIe) in an apparently asymptomatic type 2A (phenotype IIA) von Willebrand disease family.

Type 2A von Willebrand disease (VWD) is mostly an autosomal dominantly inherited bleeding disorder characterised by a qualitative defect of von Willebrand factor (VWF). Mutation screening was used to screen the whole of VWF gene followed by direct sequencing to detect the mutation in a father and son diagnosed with type 2A (phenotype IIA) von Willebrand disease. A C5219 to A transversion was detected predicting Leucine to Isoleucine substitution in codon 1657. This novel missense mutation which was also identified by MboI restriction enzyme analysis, was found in both patient and his father but not in any other unaffected family member or 50 unrelated normal individuals. This substitution was reproduced by in vitro site directed mutagenesis of full-length VWF cDNA and transiently expressed in COS-7 cells. The corresponding recombinant VWF protein exhibited the full spectrum of VWF multimers, suggesting that the abnormal multimer seen in the patient results from increased proteolysis.

Amino Acid Substitution↗

A novel mutation in exon b (R259C) of the MTM1 gene is associated with a mild myotubular myopathy. Mutation in brief no. 125. Online.

The genetic basis of the relatively mild myopathic symptoms exhibited in a male was investigated. Mutation screening of a candidate gene, MTM1, represented a chance of establishing the molecular defect and the mode of inheritance. SSCA detected variation of the exon b PCR products from the proband and his mother, compared to that observed upon analysis of the PCR products from other members of the family and 159 unrelated X chromosomes. Sequencing revealed a C775 to T transition, in the proband and his mother, but not in his unaffected brother. To confirm the presence of a base change in this region, a Cfol site was introduced into the PCR product of the wildtype allele by using the forward primer 5'-AGAAAATAAGACGGTCATTGcG-3' (mismatch base in small font) with the exon b reverse primer as used by Laporte et al (1996). Analysis of DNA from other members of the family using this method revealed that this is a new mutation in the proband's mother. This mutation would result in a Arg259->Cys substitution.

Alleles↗

Plasma levels of von Willebrand factor antigen in acute bronchitis and in a normal population.

von Willebrand factor (vWF) is a large glycoprotein secreted predominantly by endothelial cells in both the systemic and pulmonary circulations and has a central role in the formation of the platelet plug. It has been put forward as a possible marker of endothelial cell injury, but is not ideal in that it is not specific for either the pulmonary or systemic circulation and may be released as part of the acute phase response from otherwise healthy endothelial cells. We undertook two studies (i) to assess within-subject to assess within-subject variation in plasma von Willebrand factor antigen (vWF:Ag) levels over time and to assess between-subject variation in a healthy patient population, and (ii) as part of a descriptive study of acute bronchitis, to assess whether plasma vWF:Ag levels altered in such a common and minor insult. A random sample of patients aged 45-74 years were taken from a local general practice. vWF:Ag levels were measured on three occasions, and spirometry was performed. The descriptive study was undertaken on patients in the general practice diagnosed with acute bronchitis without pre-existing pulmonary disease. Plasma vWF:Ag was measured on presentation and 14 and 42 days later. In 219 randomly selected patients the mean plasma vWF:Ag was similar at all three visits, the within-subject standard deviation being 0.09 U ml(-1) and 1.12 U ml(-1) respectively). There was no correlation between plasma vWF:Ag and C-reactive protein on presentation. We conclude that there is relatively little variation in an individual's plasma vWF:Ag level but that levels increase significantly with age. The observed elevation occurring with acute bronchitis is a true phenomenon; the absence of an associated acute phase response suggests that endothelial cell injury is the mechanism for the rise. These observations are important in the context of vWF as a marker of endothelial cell damage, as a common and supposedly minor insult such as acute bronchitis may markedly raise plasma levels.

Acute Disease↗

Analysis of the immunophenotype of children treated on the Medical Research Council United Kingdom Acute Lymphoblastic Leukaemia Trial XI (MRC UKALLXI). Medical Research Council Childhood Leukaemia Working Party.

Despite many years of meticulous immunophenotyping of childhood acute lymphoblastic leukaemia (ALL) cases the prognostic significance of some subtypes remains unclear. The Medical Research Council UKALLXI trial (1990-1996) in which uniform treatment has been given to 2090 children with ALL below the age of 18 years and above the age of 1 year, has afforded the opportunity to review these issues. Children with ALL of mature B cell type were not entered into this trial. Immunophenotype analysis was performed in each individual trial centre, but results were centrally reviewed in all cases, and were both available and considered adequate in 1934 (93%) of the first 2090 patients entered. The main diagnostic categories were early pre-B or null reported in 60 cases (3.1%), common ALL in 1242 (64.2%), pre-B in 252 (13.0%), 'common' or pre-B in 172 (8.9%) and T cell in 207 (10.7%) cases. Children with T cell disease were significantly more likely to be over the age of 10 years, with central nervous system disease at diagnosis and to be CD34 negative. They also had a higher incidence of high white cell count and were more likely to be of the French-American-British (FAB) L2 morphological subtype. Patients with 'null' cell disease tended to be less than 2 years or greater than 10 years of age, and CD13 and CD33 positive. CD10 was associated with lower white cell count (WBC) at diagnosis, younger age and FAB L1 morphological subtype. The presence of cytoplasmic immunoglobulin in pre-B cells was not associated with any specific clinical or laboratory features. CD34 positivity was less common in T cell patients and was associated with low WBC. Disease-free survival (DFS) and 95% confidence intervals (CI) at 5 years from diagnosis was 52% (95% CI: 44-59%) for T cell disease, 58% (95% CI: 43-73%) for early pre-B (or null cell) disease and 65% (95% CI: 62-68%) for common or pre-B disease; there being no significant difference between common and pre-B disease with regard to disease outcome. Patients with T cell disease had a worse prognosis than any other immunophenotype group (P < 0.00005). However this worse outcome was no longer significant after allowing for the other principal prognostic factors of age, gender and white cell count at diagnosis except for the very small number with WBC <20 x 10(9)/l and T cell disease. Those with CD10-positive leukaemia did better than those who were CD10 negative (P < 0.00005), with DFS at 5 years 64% (95% CI: 62-67%) for positive vs 56% (95% CI: 49-62%) for CD10 negative. CD10 positivity did not have independent significance when white count, gender and age were taken into account. CD13, CD33, and cytoplasmic mu positivity carried no prognostic significance.

Adolescent↗

Epidemiology of infection with Epstein-Barr virus types 1 and 2: lessons from the study of a T-cell-immunocompromised hemophilic cohort.

In apparent contrast to earlier work on Epstein-Barr virus (EBV) carriage in the general Caucasian population, in vitro virus isolations from human immunodeficiency virus (HIV)-positive male homosexual cohorts have shown frequent examples of multiple EBV infection and an overall prevalence of type 2 EBV strains exceeding 30%. Here we ask to what extent these findings might hold true in another T-cell-immunocompromised cohort, HIV-positive hemophilic patients. Resident EBV strains were rescued within lymphoblastoid cell lines derived from the blood and throat washings of 39 such individuals, using the same in vitro protocols of virus isolation as for the homosexual cohort. A mean of 19 independent cell lines was made per patient, and in each case the resident virus was characterized by PCR-based viral genomic analysis and by immunoblotting to reveal the viral "EBNAprint." By these criteria a significant proportion (14 of 39) of the hemophilic cohort carried more than one EBV strain, suggesting that T-cell impairment does indeed sensitize virus carriers to reinfection with new strains of exogenously transmitted virus. However, the overall incidence of type 2 EBV infection was 10%, which is close to that observed in the earlier work with healthy carriers and substantially lower than that seen in HIV-positive homosexuals. We infer that type 2 EBV is relatively rare in the general Caucasian population but has become endemic in the homosexual community.

AIDS-Related Opportunistic Infections↗

Factor VIII inhibitors in mild and moderate-severity haemophilia A. UK Haemophilia Centre Directors Organisation.

Twenty six patients with mild or moderate haemophilia A and inhibitors are described. The inhibitor was detected at a median age of 33 years, after a median of 5.5 bleeding episodes. This usually following intensive replacement therapy. The median presenting inhibitor titre was antihuman 11.6 BU/ml, antiporcine 1.45 BU/ml. Plasma basal factor VIII level declined from a median of 0.08 IU/ml to 0.01 IU/ml following the inhibitor development. This caused spontaneous bleeding in 22 and a bleeding pattern similar to acquired haemophilia in 17. Bleeding was often severe and caused two deaths. The inhibitor disappeared spontaneously, or following immune tolerance induction, in 16 cases after a median of 9 months (range 0.5-46), with a return to the original baseline VIIIC level and bleeding pattern accompanied inhibitor loss. The inhibitor persisted in the remainder of the cases over a median period of 99 months (range 17-433 months) of follow-up. Inhibitors are an uncommon complication of mild haemophilia which frequently persist and may be associated with severe, life-threatening, haemorrhage. Forty-one percent of treated haemophilic family members had a history of factor VIII inhibitors, suggesting a familial predisposition to develop inhibitors in these kindreds. Sixteen patients from 11 families were genotyped. Seven different missense mutations affecting the light chain were detected and two in the A2 domain. Five patients from three families had a mutation causing a substitution of Trp2229 by Cys in the C2 domain which appears to predispose to inhibitor formation since 7 of the 18 affected individuals have a history of inhibitor development.

Adolescent↗

Clearance of marrow infiltration after 1 week of therapy for childhood lymphoblastic leukaemia: clinical importance and the effect of daunorubicin. The Medical Research Council's Working Party on Childhood Leukaemia.

At the commencement of UKALL XI, a national MRC trial for childhood lymphoblastic leukaemia (ALL), the therapy included a bolus of daunorubicin (DR) on the first 2 d of the protocol. This component of treatment was subsequently withdrawn because of concern about long-term cardiotoxicity. All children both before and after this change of policy had their marrow status at the end of the first week assessed by central review as part of the trial to examine the clinical importance of the rate of disease clearance. This also afforded an opportunity to observe the effect of DR on gross residual disease at an early stage of therapy. 1419 children were studied: 342 received DR ('recipients'), 1077 did not. 44% of the recipients completely cleared their marrow of blast cells after 8 d compared with 13% of the non-recipients (chi2 = 158.2, P < 0.0001). The difference in the proportion with massive residual disease (>80% blasts) was less impressive but there was still a difference in favour of DR recipients (DR 9%, no DR 15%; chi2 = 7.7, P = 0.006). The rate of disease clearance correlated with disease-free survival for both recipients and non-recipients, but there was no significant difference in outcome when comparing the two groups with each other, either in terms of disease-free or relapse-free survival. DR accelerated the rate of blast cell disappearance from the marrow but the difference this made to disease free survival is small or non-existent. It appears to be the relative speed of response to a given therapeutic regimen that is prognostically important rather than the absolute rate of response when comparing one treatment with another.

Antibiotics, Antineoplastic↗