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J Wagstaff

Publications and source records attributed to J Wagstaff.

At least 37 records · Page 2Linked to original sources
PubMed1998

Genomic organization of the UBE3A/E6-AP gene and related pseudogenes.

The UBE3A gene encodes the E6-AP ubiquitin-protein ligase and has recently been shown to be mutated in Angelman syndrome patients who lack 15q11-q13 deletions or chromosome 15 paternal uniparental disomy. Previous UBE3A cDNA analysis has shown a coding region of approximately 2.6 kb and a 3'-untranslated region (UTR) of < 50 bp, whereas Northern analysis has indicated mRNA sizes of 5-8 kb. We have analyzed additional cDNA clones and provide evidence for an additional 0.5 kb of 5'-UTR and > 2 kb of 3'-UTR. We have established the genomic organization of UBE3A and the sequence of intron-exon borders. We have also mapped two highly homologous processed pseudogenes, UBE3AP1 and UBE3AP2, to chromosomes 2 and 21, respectively, and determined their genomic organization. These results will form the basis for studies of mutation and imprinting of UBE3A.

Base Sequence↗
PubMed1998

Prognostic role of clinical, pathological and biological characteristics in patients with locally advanced breast cancer.

Forty-two patients with clinical stage IIIA or IIIB breast cancer were treated with neoadjuvant chemotherapy followed by mastectomy and radiotherapy. The median follow-up was 32 months (range 10-72 months) and the median time to progression was 17 months (range 10-30 months). A multivariate analysis showed that a longer disease-free survival (DFS) was related to more chemotherapy cycles given (P = 0.003), a better pathological response to chemotherapy (P = 0.04) and fewer positive axillary lymph nodes (P = 0.05). A better overall survival (OS) was related to more chemotherapy cycles given (P = 0.03) and better pathological response to chemotherapy (P = 0.04). In patients with residual tumour after neoadjuvant chemotherapy, high levels of staining for Ki-67 was correlated with a worse DFS (P = 0.008). Other biological characteristics, including oestrogen receptor status, microvessel density (CD31 staining), P-glycoprotein (P-gp) staining and nuclear accumulation of p53, were not independent prognostic factors for either DFS or OS. If both P-gp and p53 were expressed, DFS and OS were worse in the uni- and multivariate analysis. The preliminary results of this phase II study suggest that coexpression of P-gp/p53 and a high level of staining for Ki-67 after chemotherapy are associated with a worse prognosis, and that prolonged neoadjuvant chemotherapy and the attainment of a pathological complete remission are important factors in determining outcome for patients with this disease.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1998

OA1 mutations and deletions in X-linked ocular albinism.

X-linked ocular albinism (OA1), Nettleship-Falls type, is characterized by decreased ocular pigmentation, foveal hypoplasia, nystagmus, photodysphoria, and reduced visual acuity. Affected males usually demonstrate melanin macroglobules on skin biopsy. We now report results of deletion and mutation screening of the full-length OA1 gene in 29 unrelated North American and Australian X-linked ocular albinism (OA) probands, including five with additional, nonocular phenotypic abnormalities (Schnur et al. 1994). We detected 13 intragenic gene deletions, including 3 of exon 1, 2 of exon 2, 2 of exon 4, and 6 others, which span exons 2-8. Eight new missense mutations were identified, which cluster within exons 1, 2, 3, and 6 in conserved and/or putative transmembrane domains of the protein. There was also a splice acceptor-site mutation, a nonsense mutation, a single base deletion, and a previously reported 17-bp exon 1 deletion. All patients with nonocular phenotypic abnormalities had detectable mutations. In summary, 26 (approximately 90%) of 29 probands had detectable alterations of OA1, thus confirming that OA1 is the major locus for X-linked OA.

Albinism, Ocular↗
PubMed1998

Mutation analysis of UBE3A in Angelman syndrome patients.

Angelman syndrome (AS) is caused by chromosome 15q11-q13 deletions of maternal origin, by paternal uniparental disomy (UPD) 15, by imprinting defects, and by mutations in the UBE3A gene. UBE3A encodes a ubiquitin-protein ligase and shows brain-specific imprinting. Here we describe UBE3A coding-region mutations detected by SSCP analysis in 13 AS individuals or families. Two identical de novo 5-bp duplications in exon 16 were found. Among the other 11 unique mutations, 8 were small deletions or insertions predicted to cause frameshifts, 1 was a mutation to a stop codon, 1 was a missense mutation, and 1 was predicted to cause insertion of an isoleucine in the hect domain of the UBE3A protein, which functions in E2 binding and ubiquitin transfer. Eight of the cases were familial, and five were sporadic. In two familial cases and one sporadic case, mosaicism for UBE3A mutations was detected: in the mother of three AS sons, in the maternal grandfather of two AS first cousins, and in the mother of an AS daughter. The frequencies with which we detected mutations were 5 (14%) of 35 in sporadic cases and 8 (80%) of 10 in familial cases.

Angelman Syndrome↗
PubMed1997

Interleukin-6 downregulates factor XII production by human hepatoma cell line (HepG2).

Involvement of the contact system of coagulation in the pathogenesis of various inflammatory diseases is suggested by reduced plasma levels of factor XII (Hageman factor) and prekallikrein generally considered to result from activation of the contact system. However, in many of these diseases patients develop an acute-phase response and, therefore, an alternative explanation for the decreased levels of factor XII could be the downregulation of factor XII gene expression in the liver as described for negative acute-phase proteins. We report here that interleukin-6 (IL-6), the principal cytokine mediating the synthesis of most acute-phase proteins in the liver, downregulates the production of factor XII by the human hepatoma cell line HepG2 by up to 75%. The decrease in protein secretion correlated with an equivalent decrease of factor XII mRNA likely indicating a pretranslational control of factor XII gene expression by IL-6. Downregulation of factor XII production by IL-6 in vitro parallelled that of transthyretin, a known negative acute-phase protein. Moreover, we show that, in patients developing an acute-phase response after immunotherapy with IL-2, plasma levels of factor XII correlate (r = .76, P < .0001) with those of transthyretin. Taken together, these results suggest that factor XII behaves as a negative acute-phase protein.

Acute-Phase Reaction↗
PubMed1997

Multiple cycles of high-dose doxorubicin and cyclophosphamide with G-CSF mobilized peripheral blood progenitor cell support in patients with metastatic breast cancer.

BACKGROUND: In a previous study we applied doxorubicin and cyclophosphamide in a dose-intensive regimen with GM-CSF to patients with metastatic breast cancer (MBC). That treatment failed to prolong the remission duration compared to conventional-dose chemotherapy. In the present study we escalated the dosages of the same agents to: 1) determine the maximum tolerated dosages (MTD) when given for three cycles with G-CSF mobilised peripheral blood progenitor cell (PBPC) reinfusion and 2) evaluate the antitumour effect of this regimen. PATIENTS AND METHODS: For mobilisation of PBPC, G-CSF 15 microg/kg/day was given subcutaneously (s.c.), and in subsequent cohorts leucapheresis was started on days 3, 4 or 6. The intention was to treat MBC patients with three cycles of doxorubicin and cyclophosphamide at a starting dose of doxorubicin 90 mg/m2 and cyclophosphamide 1000 mg/m2. Dosages were then escalated in subsequent cohorts of at least three patients. In case of dose-limiting mucositis, only the dose of cyclophosphamide was escalated in the next cohort. RESULTS: Twenty-one patients entered this protocol, of which 18 patients received high-dose chemotherapy. The mobilisation of PBPC using G-CSF only was sufficient for three cycles of high-dose chemotherapy in 10 of 21 (47%) patients. Mucositis precluded dose escalation of doxorubicin beyond 110 mg/m2. The MTD in this combination was 110 mg/m2 for doxorubicin, and 4 g/m2 for cyclophosphamide, with haemorrhagic cystitis being the dose-limiting toxicity. The overall response rate was 78% (95% confidence interval (95% CI): 57%-97%), with 22% (95% CI: 3%-41%) complete responses. CONCLUSION: The MTD of this three cycle high-dose regimen was doxorubicin 110 mg/m2 and cyclophosphamide 4 g/m2 with mucositis and cystitis being dose-limiting toxicities. Although the primary aim was not the evaluation of antitumour effect, this high-dose regimen does not appear to provide an improvement of treatment results in comparison with our previous study with the same drugs at moderately high-dosages without stem cell support.

Adult↗
PubMed1997

UBE3A/E6-AP mutations cause Angelman syndrome.

Angelman syndrome (AS), characterized by mental retardation, seizures, frequent smiling and laughter, and abnormal gait, is one of the best examples of human disease in which genetic imprinting plays a role. In about 70% of cases, AS is caused by de novo maternal deletions at 15q11-q13 (ref. 2). Approximately 2% of AS cases are caused by paternal uniparental disomy (UPD) of chromosome 15 (ref. 3) and 2-3% are caused by "imprinting mutations'. In the remaining 25% of AS cases, no deletion, uniparental disomy (UPD), or methylation abnormality is detectable, and these cases, unlike deletions or UPD, can be familial. These cases are likely to result from mutations in a gene that is expressed either exclusively or preferentially from the maternal chromosome 15. We have found that a 15q inversion inherited by an AS child from her normal mother disrupts the 5' end of the UBE3A (E6-AP) gene, the product of which functions in protein ubiquitination. We have looked for novel UBE3A mutations in nondeletion/non-UPD/non-imprinting mutation (NDUI) AS patients and have found one patient who is heterozygous for a 5-bp de novo tandem duplication. We have also found in two brothers a heterozygous mutation, an A to G transition that creates a new 3' splice junction 7 bp upstream from the normal splice junction. Both mutations are predicted to cause a frameshift and premature termination of translation. Our results demonstrate that UBE3A mutations are one cause of AS and indicate a possible abnormality in ubiquitin-mediated protein degradation during brain development in this disease.

Amino Acid Sequence↗
PubMed1997

Effects of chemotherapy on pathologic and biologic characteristics of locally advanced breast cancer.

In 42 patients with locally advanced breast cancer treated with neoadjuvant chemotherapy followed by surgery and radiation therapy, the effects of chemotherapy on tumor architecture, morphometric nuclear and nucleolar characteristics, DNA ploidy, proliferation index measured by mitotic activity index, expression of differentiation antigens, and microvessel density were studied. Pretreatment biopsy specimens were available to compare with mastectomy specimens for 24 patients, and subclavicular biopsy specimens taken before chemotherapy were available for 9 patients. In the remaining patients, fine-needle aspiration was performed before chemotherapy, and morphologic and biologic features of the tumors could be studied only after chemotherapy. In 23 patients, only microscopic tumor or no tumor was left after chemotherapy, and in these patients we observed a characteristic pattern of relatively cellular fibrous tissue with lymphocytic infiltrate, ironloaded macrophages, and, when present, scattered foci of tumor cells in between. We found a reduction in mitotic activity index and in global microvessel density over all the tumors as a group. There was, however, no consistent pattern of changes in nuclear and nucleolar morphometric characteristics, DNA ploidy, and expression of differentiation antigens, and no pathologic or biologic features were predictive for response to chemotherapy.

Adult↗
PubMed1997

T cell receptor-zeta and granzyme B expression in mononuclear cell infiltrates in normal colon mucosa and colon carcinoma.

BACKGROUND: Whereas the presence of a lymphoid infiltrate has been associated with a favourable prognosis in colorectal carcinoma, the proliferative and cytotoxic responses of freshly isolated tumour infiltrating lymphocytes are frequently impaired. In mice, tumour induced immune suppression has been associated with a decreased expression of the zeta-chain of the T cell receptor (TCR)-CD3 complex, and loss of mRNA for granzyme B. AIM: To compare the expression of TCR-zeta and granzyme B in lymphocytes infiltrating normal colonic mucosa and Duke's A and D colorectal carcinomas. SPECIMENS: Paraffin wax embedded normal (n = 10) and malignant colonic mucosa (seven Dukes's A, nine Dukes's D). METHOD: Immunohistochemistry. RESULTS: The numbers of TCR-zeta + lymphocytes decreased from normal mucosa to Dukes's D carcinomas. In contrast, granzyme B+ lymphocytes were more frequent in Dukes's A carcinomas than in normal mucosa, but disappeared from advanced stage tumours. Granzyme B expressing cells were mainly CD3- (natural killer/lymphokine activated killer cells) in normal mucosa, but CD3+ in tumours, indicating the presence of activated cytotoxic T lymphocytes. In vitro culture of tumour infiltrating lymphocytes rapidly restored the expression of both molecules. CONCLUSION: The frequency of TCR-zeta + and granzyme B+ lymphocytes is decreased in advanced stage colorectal carcinomas. The restoration of expression during in vitro stimulation suggests the presence of tumour derived suppressive factors in situ.

CD3 Complex↗
PubMed1997

Angelman syndrome associated with an inversion of chromosome 15q11.2q24.3.

Angelman syndrome (AS) most frequently results from large (> or = 5 Mb) de novo deletions of chromosome 15q11-q13. The deletions are exclusively of maternal origin, and a few cases of paternal uniparental disomy of chromosome 15 have been reported. The latter finding indicates that AS is caused by the absence of a maternal contribution to the imprinted 15q11-q13 region. Failure to inherit a paternal 15q11-q13 contribution results in the clinically distinct disorder of Prader-Willi syndrome. Cases of AS resulting from translocations or pericentric inversions have been observed to be associated with deletions, and there have been no confirmed reports of balanced rearrangements in AS. We report the first such case involving a paracentric inversion with a breakpoint located approximately 25 kb proximal to the reference marker D15S10. This inversion has been inherited from a phenotypically normal mother. No deletion is evident by molecular analysis in this case, by use of cloned fragments mapped to within approximately 1 kb of the inversion breakpoint. Several hypotheses are discussed to explain the relationship between the inversion and the AS phenotype.

Angelman Syndrome↗
PubMed1997

Low intercellular adhesion molecule 1 and high 5T4 expression on tumor cells correlate with reduced disease-free survival in colorectal carcinoma patients.

The purpose of this study was to investigate the prognostic value of the expression of intercellular adhesion molecule 1 (ICAM-1), leukocyte function antigen 3 (LFA-3), human leukocyte differentiation antigen (HLA)-ABC, HLA-DR, and 5T4 with regard to disease-free survival in Dukes' B and C colorectal carcinoma patients. Forty-one patients (28 Dukes' B and 13 Dukes' C) were entered into this study. Immunocytochemistry was performed on cytospin preparations of enzymatically digested colorectal carcinoma cell suspensions. The frequency of metastases and the duration of disease-free survival were compared between the 25% lowest expressers and the 75% remaining patients for ICAM-1, LFA-3, HLA-ABC, and HLA-DR, and between the 25% highest expressers and the 75% remaining patients for 5T4. Low numbers of ICAM-1-expressing tumor cells were associated with a shorter disease-free survival (P < 0. 001), independent of Dukes' stage. High numbers of 5T4-expressing tumor cells were associated with shorter disease-free survival in Dukes' B patients (P = 0.04). Cox proportional hazard analysis indicated that low numbers of ICAM-1(+) and high numbers of 5T4(+) cells were independent prognostic factors with relative risks of 13. 0 (P = 0.0002) and 4.7 (P = 0.02), respectively. The combination of 5T4 and ICAM-1 marker information identified subgroups of patients with a good (high ICAM-1) or poor (low ICAM-1/high 5T4) prognosis. Neither a lack of HLA-ABC and LFA-3 expression nor the presence of HLA-DR on the tumor cells gave additional prognostic information. These findings demonstrate that low ICAM-1 and high 5T4 expression on tumor cells are prognostic markers, additional to Dukes' stage, for reduced disease-free survival in Dukes' B and C colorectal carcinoma patients.

Aged↗
PubMed1996

IL-1 beta does not cause neutrophil degranulation but does lead to IL-6, IL-8, and nitrite/nitrate release when used in patients with cancer.

The use of IL-1 in humans is associated with dose-limiting toxicity which resembles that of TNF-alpha or IL-2. Activation of neutrophils is thought to contribute to the toxicity caused by these two cytokines. We studied the effect of IL-1 in vivo on changes in neutrophil numbers and neutrophil degranulation as well as on the formation of neutrophil agonists, such as complement activation products, and on levels of TNF, IL-6, IL-8, and nitrite/nitrate (as a measure of nitric oxide production). Six patients with metastatic melanoma were treated with 3 ng/kg recombinant human IL-1 beta daily. One hour after the start of the 30-min IL-1 infusion, which caused mild cardiovascular toxicity, plasma levels of IL-6 reached a peak of 25 +/- 9 ng/L (mean +/- SEM), IL-8 reached a peak of 311 +/- 100 ng/L at 2 h, and nitrite/nitrate peaked after 10 h to 89 +/- 27 mumol/L. IL-1 did not induce significant changes in plasma levels of TNF or of the complement activation products C3a and C4b/c. Although IL-1 induced neutrophilia, levels of elastase and lactoferrin did not change. The failure of IL-1 to degranulate neutrophils was confirmed in an ex vivo model with whole blood culture in which doses of up to 100 microgram/L IL-1 beta or IL-1 alpha failed to induce significant elastase or lactoferrin release, whereas TNF, tested as a positive control, was able to do so. These results demonstrate that, unlike TNF, IL-1 does not cause neutrophil degranulation in man, despite its ability to cause neutrophilia and the rapid release of IL-6, IL-8, and nitrite/nitrate.

Adult↗
PubMed1996

Mucin-1-related T cell infiltration in colorectal carcinoma.

Mucins (MUC) are highly glycosylated molecules widely expressed on epithelia of different origins, including colonic mucosa. Altered glycosylation processes in tumour cells result in the exposure of normally cryptic peptide epitopes, which may then be recognized as tumour-specific antigens. Recently, MUC1-specific antibodies were detected in the serum of a broad range of cancer patients, and from different tumours tumour-specific cytotoxic T lymphocytes (CTL) were isolated that recognized MUC1. Absence of HLA restriction in the recognition has been ascribed to the highly repetitive sequence of the polypeptide core, allowing simultaneous recognition of multiple identical epitopes and cross-linking and aggregation of T cell receptor on mucin-specific T cells. We investigated the expression of MUC1 epitopes in 56 cell suspensions from Dukes' B to D colorectal carcinomas using antibodies that recognize distinct peptide sequences on the glycosylated or deglycosylated MUC1 protein backbone. No relation was observed between MUC1 expression, or the extent of its glycosylation, and Dukes' stage, tumour location and tumour differentiation, but a positive correlation was detected between the percentages of tumour cells expressing mucin-1 and the numbers of CD3+ infiltrating cells. These tumour-infiltrating lymphocytes contained, however, only a few MUC1-specific T lymphocytes, as CTL showing preferential killing of MUC1-expressing target cells were only obtained from one tumour. Since, in addition, the majority of colorectal carcinomas were found to express the fully glycosylated MUC1 glycoprotein, its potential role as a target antigen for T-lymphocyte-mediated immunotherapy in this tumour type is probably limited.

Antibodies, Monoclonal↗
PubMed1996

Continuous infusion or subcutaneous injection of granulocyte-macrophage colony-stimulating factor: increased efficacy and reduced toxicity when given subcutaneously.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a haematopoietic growth factor with a wide variety of applications in the clinic. In early phase I studies the continuous intravenous (c.i.) route of administration was often used. Later it was shown that subcutaneous (s.c.) administration was also effective. The optimal route of administration remains, however, poorly defined, and no studies have made a direct comparison between these two routes of administration. We treated patients with advanced breast cancer with moderately high-dose doxorubicin and cylophosphamide and GM-CSF. The first 14 patients received GM-CSF by c.i, while subsequently 47 patients received it s.c. Comparison between the two groups showed that c.i. GM-CSF was more toxic in several respects. There was a higher need for erythrocyte and platelet transfusions and a significant deterioration in the performance status. This study indicates that subcutaneous GM-CSF is the preferred route of administration. Randomised trials are, however, needed to confirm these conclusions.

Adult↗
PubMed1996

Dose-intensive chemotherapy with doxorubicin, cyclophosphamide and GM-CSF fails to improve survival of metastatic breast cancer patients.

BACKGROUND: A dose response relationship for doxorubicin and cyclophosphamide has been suggested. In a previous dose finding study we treated advanced breast cancer patients with escalating doses of doxorubicin and cyclophosphamide in combination with GM-CSF. The aim of this study is to further define the acute and cumulative toxicity of this treatment in relation to its antitumor activity. PATIENTS AND METHODS: Twenty-eight patients with metastatic breast cancer were treated with doxorubicin (90 mg/m2) and cyclophosphamide (1000 mg/m2) at 3-week intervals. Dose reductions of 10% were applied in the second and fourth cycles. On the second day GM-CSF was started at 250 mu g/m2 daily for 10 days. The intention was to give 6 cycles, but when a complete remission was reached earlier only one more cycle was given as consolidation. RESULTS: The median number of cycles was 5 (range 2-6). Twenty-three patients responded (82%, 95% CI 69%-97%), with 9 of them achieving a complete response (32%, 95% CI 14%-50%). For the 18 patients evaluable for time to progression and survival the median time to progression was 8 months and the median survival 14.5 months. Toxicity was substantial: grades 3 or 4 neutropenia occurred in 95% of cycles and grades 3-4 thrombocytopenia in 49% of cycles. Grade 3-4 mucositis was present in 13% of the cycles. Weakness and fatigue were always present and were cumulative. Four patients had a decline in the left ventricular ejection fraction (LVEF). These side effects were the reason for discontinuing therapy in 9 of the 28 patients (32%). CONCLUSION: This treatment has a high response rate in comparison with conventional-dose chemotherapy but does not prolong time to progression or survival. The toxicity makes this protocol unsuitable for use as palliative treatment.

Adult↗
PubMed1995

17q inversion involving the neurofibromatosis type one locus in a family with neurofibromatosis type one.

We report a family with a paracentric inversion of the long arm of chromosome 17 [inv(17)(q11.2q25.1)] and neurofibromatosis type one (NF1). The family was ascertained because of NF1 and multiple miscarriages. Fluorescence in situ hybridization using cosmid probes from opposite ends of the NF1 gene confirmed that the inversion disrupts the gene. Using field inversion gel electrophoresis we have found that the inversion separates cDNA probes FB5D and AE25, which are normally adjacent to one another in the NF1 gene. This is the third published report of a gross chromosomal rearrangement responsible for NF1. The features in this family are typical for NF1, and are not unusually severe.

Adolescent↗