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J Wagstaff

Publications and source records attributed to J Wagstaff.

At least 73 records · Page 4Linked to original sources
PubMed1993

A cluster of three GABAA receptor subunit genes is deleted in a neurological mutant of the mouse p locus.

The mouse pink-eyed cleft-palate (p(cp)) mutation is characterized by hypopigmentation associated with cleft palate, neurological disorders and runting. Most p(cp) homozygotes are born with cleft palate and die shortly after birth, presumably as a result of feeding problems. A few exceptional p(cp) mutants live beyond this stage but display tremor and jerky gait. We report here that the genes encoding the gamma-aminobutyric acid type A (GABAA) receptor subunits alpha 5 (originally described as alpha 4; ref. 4), beta 3 and gamma 3 are disrupted by a deletion in p(cp) mice. We also show that the alpha 5 and gamma 3 genes are located between the p and beta 3 genes on mouse chromosome 7. The p(cp) deletion leads to alterations of binding properties of the GABAA receptors in the brain, providing an in vivo model system for studying GABAA receptor function. The human homologue of the region deleted in p(cp) mice is associated with Angelman syndrome. Thus, p(cp) mice may be useful in defining the region containing the gene(s) for this syndrome.

Animals↗
PubMed1993

Cytogenetic and molecular studies in the Prader-Willi and Angelman syndromes: an overview.

The majority of patients with Angelman syndrome and Prader-Willi syndrome have a cytogenetic and molecular deletion of chromosome 15q11q13 with the primary difference being in the parental origin of deletion. Our current understanding of the cytogenetics and molecular genetics of these 2 clinically distinct syndromes will be discussed in this review.

Angelman Syndrome↗
PubMed1993

Determination of capillary leakage due to recombinant interleukin-2 by means of noninvasive conductivity measurements.

One of the most common side effects of treatment with recombinant interleukin-2 (IL-2) is capillary leakage. Its genesis is not completely understood. The aim of the study was to determine whether capillary leakage can be monitored by means of a noninvasive conductivity technique and to study its starting point. Eight patients with advanced renal cell cancer were studied in a medium care section of the Department of Medical Oncology, University Hospital over 4 days during treatment sessions of continuous, intravenously administered IL-2 (mean dose of 15.6 x 10(6) IU.m-2.day-1). The fluid shift from the intravascular to the extra- and intracellular compartments was monitored by means of noninvasive conductivity measurements. Changes in blood volume were calculated from serial erythrocyte counts. The clinical parameters of capillary leakage (oliguria, positive fluid balance, and gain in mass) were recorded. The mean gain in mass was 9% after 4 days of IL-2 treatment. The extracellular fluid volume increased significantly [46 (SD 23.2)%; P < 0.01], whereas the intracellular fluid volume did not change. The increase in blood volume (BV) amounted to 7% (P < 0.05). The decline in albumin concentration was significantly more than the increase in BV [38 (SD 4.3)%; P < 0.01], indicating capillary albumin leakage. The main changes were observed after the 2nd day of treatment. From this study, it is suggested that conductivity measurements are a suitable method to monitor capillary leakage induced by IL-2, and could be used to detect the exact onset and severity of this leakage.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

C1-inhibitor substitution therapy in septic shock and in the vascular leak syndrome induced by high doses of interleukin-2.

C1-inhibitor (C1-INH) is the major plasma inhibitor of the complement and contact systems. Activation of either system has been shown to occur in patients with septic shock and is associated with a poor outcome. Functional levels of C1-INH tend to be normal in septic patients although paradoxically this inhibitor is an acute phase protein. Moreover, levels of proteolytically inactivated C1-INH are increased in sepsis pointing to an increased turn-over. These observations suggest a relative deficiency of biologically active C1-INH in sepsis. Complement and contact activation have also been shown to occur in the vascular leak syndrome (VLS) induced by immunotherapy with the cytokine interleukin-2 (IL-2), which syndrome may be regarded as a human model for septic shock. The similarity between VLS and sepsis encompasses more than complement and contact activation since a number of other inflammatory mediators considered to play a role in the pathogenesis of septic shock, are also involved in the development of VLS. The role and the mechanisms of complement and contact activation in sepsis and in the VLS are reviewed in this paper. Initial results of intervention therapy with high doses of C1-INH in these syndromes are also reported. It is concluded that high doses of C1-INH can be safely administered to patients with septic shock or with the VLS and may attenuate complement and contact activation in these conditions. Double-blind controlled studies are needed to definitely proved these effects and to establish whether this treatment is able to reduce mortality and morbidity of these syndromes.

Blood Coagulation↗
PubMed1993

Effects of interleukin-3 on myelosuppression induced by chemotherapy for ovarian cancer and small cell undifferentiated tumours.

Two clinical studies were undertaken to study the toxicity profile and effects of interleukin-3 (rhIL-3) on chemotherapy-induced myelosuppression. Fifteen patients with recurrent ovarian carcinoma were treated with high dose carboplatin (800 mg m-2). All patients received 5.0 micrograms/kg/d rhIL-3 subcutaneously but timing and duration of rhIL-3 treatment differed. Constitutional symptoms were the major toxicity and in addition to the carboplatin-induced nausea and vomiting the combination was poorly tolerated. In 5/15 patients receiving high dose carboplatin rhIL-3 administration was discontinued due to nephrotoxicity (2 x), hypotension, severe malaise and bone pain. In this study, rhIL-3 ameliorated chemotherapy-induced neutropenia as well as thrombocytopenia and reduced the requirement for platelet transfusions in the second cycle of chemotherapy. However, rhIL-3 failed to prevent cumulative platelet toxicity. In the second study 12 patients with small cell undifferentiated cancers were treated with carboplatin, etoposide and ifosfamide. Three dose levels of rhIL-3 were explored (0.125, 5.0 and 7.5 micrograms/kg/d). In this study, toxicity of the treatment was mild, however, no beneficial haematologic effects of rhIL-3 could be demonstrated. In conclusion, the haematological effects of rhIL-3 were modest and dependent on the chemotherapeutic regimen, timing and duration of rhIL-3 treatment (in relation to the expected nadir). In general rhIL-3-induced toxicity was mild, but combination with high dose carboplatin could be hazardous if rhIL-3 is initiated at 24 h after the cytostatic agent.

Adult↗
PubMed1993

FISH ordering of reference markers and of the gene for the alpha 5 subunit of the gamma-aminobutyric acid receptor (GABRA5) within the Angelman and Prader-Willi syndrome chromosomal regions.

We have established a probe order within the Angelman/Prader-Willi chromosomal regions by multicolor fluorescence in situ hybridization (FISH). The probe [locus] order extending distally from the centromere is 34[D15S9]-IR4-3R[D15S11]-189-1[D15S13]-PW71++ + [D15S63]-3-21[D15S10]-28 beta 3-H3[GABRB3]-IR10-1 [D15S12]. This order agrees with that recently reported (1) with the exception of PW71 [D15S63]. In addition, a second gamma-aminobutyric acid (GABAA) receptor, the alpha 5 subunit, has been localized within the reference map to between GABRB3 and D15S12. The locus order was further confirmed by DNA hybridization analysis of two patients, one with Angelman syndrome and one with Prader-Willi syndrome, with different unbalanced translocations and molecular extents of deletion. Our results provide a framework map of chromosome 15q11-q13 into which additional markers can be oriented and allow a further differentiation of the critical genetic regions of the two syndromes.

Amino Acid Sequence↗
PubMed1993

Uniparental disomy explains the occurrence of the Angelman or Prader-Willi syndrome in patients with an additional small inv dup(15) chromosome.

A patient with Angelman syndrome and a 46,XY/47,XY,+inv dup(15)(pter-->q11: q11-->pter) karyotype and a patient with Prader-Willi syndrome and a 46,XY/47,XY,+inv dup(15)(pter-->q12: q12-->pter) karyotype were investigated with molecular markers along chromosome 15. Paternal uniparental isodisomy was found for all informative markers in the first case which indicates that this, rather than the presence of the extra chromosome, is the cause of the Angelman syndrome phenotype. Similarly, the PWS patient showed maternal uniparental distomy with absence of PWS region material on the inv dup(15) chromosome. If (1) marker chromosomes are an occasional by product of 'rescuing' a trisomic fertilisation, or (2) if duplication of the normal homologue in a zygote which has inherited a marker in place of the normal corresponding chromosome 'rescues' an aneuploid fertilisation, or (3) if the presence or formation of a marker chromosome increases the probability of non-disjunction, then uniparental disomy might be found occasionally in other subjects with de novo marker chromosomes.

Angelman Syndrome↗
PubMed1993

Linkage analysis in familial Angelman syndrome.

Familial Angelman syndrome (AS) can result from mutations in chromosome 15q11q13 that, when transmitted from father to child, result in no phenotypic abnormality but, when transmitted from mother to child, cause AS. These mutations therefore behave neither as dominant nor as recessive mutations but, rather, show an imprinted mode of inheritance. We have analyzed two sibling pairs with AS and a larger family with four AS offspring of three sisters with several recently described microsatellite polymorphisms in the AS region. AS siblings inherited the same maternal alleles at the GABRB3 and GABRA5 loci, and the unaffected siblings of AS individuals inherited the other maternal alleles at these loci. In one of the AS sibling pairs, analysis of a recombination event indicates that the mutation responsible for AS is distal to locus D15S63. This result is consistent with a previously described imprinted submicroscopic deletion causing AS, a deletion that includes loci D15S10, D15S113, and GABRB3, all distal to D15S63. The analysis of the larger AS family provides the first clear demonstration of a new mutation in nondeletion AS. Analysis of linkage of AS to GABRB3 in these three families, on the assumption of imprinted inheritance (i.e., penetrance of an AS mutation is 1 if transmitted maternally and is 0 if transmitted paternally), indicates a maximum lod score of 3.52 at theta = 0.

Angelman Syndrome↗
PubMed1993

High-resolution mapping of the gamma-aminobutyric acid receptor subunit beta 3 and alpha 5 gene cluster on chromosome 15q11-q13, and localization of breakpoints in two Angelman syndrome patients.

The gamma-aminobutyric acid (GABAA) receptors are a family of ligand-gated chloride channels constituting the major inhibitory neurotransmitter receptors in the nervous system. In order to determine the genomic organization of the GABAA receptor beta 3 subunit gene (GABRB3) and alpha 5 subunit gene (GABRA5) in chromosome 15q11-q13, we have constructed a high-resolution physical map using the combined techniques of field-inversion gel electrophoresis and phage genomic library screening. This map, which covers nearly 1.0 Mb, shows that GABRB3 and GABRA5 are separated by less than 100 kb and are arranged in a head-to-head configuration. GABRB3 encompasses approximately 250 kb, while GABRA5 is contained within 70 kb. This difference in size is due in large part to an intron of 150 kb within GABRB3. We have also identified seven putative CpG islands within a 600-kb interval. Chromosomal rearrangement breakpoints--in one Angelman syndrome (AS) patient with an unbalanced translocation and in another patient with a submicroscopic deletion--are located within the large GABRB3 intron. These findings will facilitate chromosomal walking strategies for cloning the regions disrupted by the DNA rearrangements in these AS patients and will be valuable for mapping new genes to the AS chromosomal region.

Angelman Syndrome↗
PubMed1992

The effect of schedule, protein binding and growth factors on the activity of suramin.

Suramin has been shown to have antiproliferative activity, either by blocking the binding of growth factors to their receptors or by inhibiting critical cellular enzymes. In 6 different cell lines from 5 tumour types (MCF-7, MCF-7/ADRR, PC3, HT-29, UM-SCC-11B and SW-1573/IR500), we studied the effect of scheduling of suramin, of FCS and of human serum albumin (HSA), of epidermal growth factor (EGF) and of the addition of growth factors in serum-free medium on the activity of suramin. The concentration of suramin which gave 50% growth inhibition (IC50) varied from 45 microM in SW-1573/IR500 to 153 microM in PC3 cells grown in medium supplemented with 5% FCS, after 6 days of continuous exposure. Exposure for more than 4 days did not enhance the sensitivity to suramin, except in PC3. At exposure to suramin for 1 day followed by 5 days recovery, high IC50 values (greater than 0.5 mM) were observed in MCF-7 cells. In medium with 1% and 0.5% FCS these values were 3 to 8 and 14 to 26 times lower respectively. Addition of HSA increased the IC50 in PC3 and MCF-7 cells. Suramin binding to protein was dependent on the concentration of protein and of suramin. Excess of EGF in medium with different FCS concentrations did not change the IC50 values of suramin in PC3 and MCF-7 cells. Addition of EGF, fibroblast growth factor or platelet-derived growth factor in PC3 cells cultured in serum-free medium did not increase the IC50 values. Suramin was active against these 6 cell lines at clinically achievable concentrations. This activity varied depending on the cell line, exposure time and suramin concentration. The most significant factor interfering with sensitivity to suramin was the amount of protein present in the culture medium.

Blood↗
PubMed1992

Treatment with tumour infiltrating lymphocytes and interleukin-2 in patients with metastatic melanoma: a pilot study.

Tumour infiltrating lymphocytes (TIL) were isolated and expanded from biopsy samples of 4 patients with metastatic melanoma. The patients were treated with autologous expanded TIL and continuous or bolus infusion of Interleukin 2 (IL-2) at a dose of 18 x 10(6) International Units/m2/day for 5 days starting 36-48 hours after administration of cyclophosphamide at a dose of 1 g/m2. The number of TIL infused ranged from 10(10) to 5.56 x 10(10) cells. Two patients had stable disease (SD) lasting for 2 1/2 and 4 months respectively and they died 24 and 13 months after therapy. One patient died during therapy due to a pseudomonas septicaemia and another patient developed progressive disease (PD). He died 3 months after the start of therapy. The side effects were substantial but most of them were reversible upon cessation of the treatment. The majority of the expanded TIL of all patients were of the CD8+ phenotype. Cutaneous metastases from two patients, removed after treatment with IL-2 and TIL, showed moderate lymphocytic infiltration also mainly of CD8+ T cells. The treatment with IL-2 and TIL is feasible, but further investigations should continue in an attempt to improve the efficacy of the therapy, to reduce toxicity and to diminish the costs and labour of the culture methods.

Cell Division↗
PubMed1992

A dose-escalation study of recombinant interferon-alpha in patients with a metastatic carcinoid tumour.

The efficacy of interferon alpha-2b in doses up to 12 x 10(6) IU three times weekly was studied in 21 patients with a metastatic carcinoid tumour. Of these 21 patients, 19 were evaluable for response. Patients were treated with escalating dosages of interferon alpha-2b: 3 x 10(6) IU, 6 x 10(6) IU and 12 x 10(6) IU. The escalation was performed every 8 weeks when no objective tumour regression was observed. Patients were also evaluated for biochemical response and symptomatic improvement. One objective tumour regression was observed. Of the 15 patients with elevated 5-hydroxyindole acetic acid (5-HIAA) excretion, 5 (33%) had a more than 50% decrease in 5-HIAA excretion. Relief of symptoms occurred in 11 patients (58%). This improvement was already apparent during the initial 8 weeks of treatment. Increasing the dose to 6 or 12 x 10(6) IU interferon alpha-2b did not result in further symptomatic improvement. In contrast toxicity was considerable with the higher dosages of interferon alpha-2b. It is concluded that low dose interferon alpha-2b (3 x 10(6) IU) three times weekly is as effective as higher dosages of interferon alpha-2b at ameliorating symptoms of the carcinoid syndrome.

Adult↗
PubMed1992

The activation of polymorphonuclear neutrophils and the complement system during immunotherapy with recombinant interleukin-2.

The toxicity due to interleukin-2 (IL-2) strongly resembles the clinical picture seen during septic shock. In septic shock activation of polymorphonuclear neutrophils (PMN) and the complement system contribute significantly to the pathophysiology of the condition. We therefore investigated whether similar events contributed to the toxicity observed with IL-2. Four patients received seven cycles of escalating dose IL-2 (18.0 to 72.0 X 10(6) IU m-2 day-1) and 16 were treated with 20 cycles of fixed dose IL-2 (12.0 or 18.0 X 10(6) IU m-2 day-1). Toxicity, as judged by hypotension (P = less than 0.005) and capillary leakage (fall in serum albumin 18.2 vs 4.0 gm l-1; P = less than 0.0005 and weight gain 4.0 vs 1.2 kg; P = less than 0.025) were worse with the esc. dose protocol. PMN became activated following IL-2 with mean peak elastase/alpha 1-antitrypsin (E alpha 1 A) and lactoferrin values of 212 (SEM = 37) and 534 (SEM = 92) ng ml-1 respectively occurring 6 h after the IL-2. Peak values for the esc. dose IL-2 group being generally higher than 500 ng ml-1. Activation of the complement cascade was evidenced by a dose dependent elevation of peak C3a values (fixed dose 9.1 (SEM = 0.6); esc. dose 25.7 (SEM = 6.33); P = less than 0.005) on day 5 of IL-2. There was a significant correlation between C3a levels and the degree of hypotention during the first 24 h after IL-2 (r = 0.91) and parameters of capillary leakage such as weight gain and fall in serum albumin (r = 0.71). These data suggest that activation of PMN initiates endothelial cell damage which subsequently leads to activation of the complement cascade. This latter system then contributes to the haemodynamic changes and capillary leakage seen in IL-2 treated patients.

Carcinoma, Renal Cell↗
PubMed1992

Lobular panniculitis after subcutaneous administration of interleukin-2 (IL-2), and its exacerbation during intravenous therapy with IL-2.

Interleukin-2 (IL-2) is now registered for the treatment of renal cell carcinoma in a number of European countries. The subcutaneous (sc) route of administration is being used increasingly because of its better toxicity profile compared with higher dose intravenous (iv) protocols. We report here a patient who developed a lobular panniculitis at the site of sc IL-2 injection which prevents continuation of sc therapy. Subsequent administration of the same IL-2 dose by iv injection caused recurrence of the problem again necessitating discontinuation of IL-2 treatment.

Adult↗