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Biomedical subjects

G J Williams

Publications and source records attributed to G J Williams.

At least 37 records · Page 2Linked to original sources
PubMed1997

Multiple myeloma presenting clinically as lymphoma.

Multiple myeloma typically presents with monoclonal proteinemia, marrow plasmacytosis, anemia, bony involvement, hypercalcemia and renal insufficiency. Less frequent presentations include hepatic and splenic enlargement (5% of cases), lymphadenopathy (4%) and biclonal gammopathy (1%). Chemotherapy may produce remissions in 50% of cases, but relapses are the rule and mean survival is approximately 2.5 years. To improve survival, marrow transplantation is being explored as a therapeutic modality in younger patients. In this report we describe a unique case of multiple myeloma presenting clinically as lymphoma. The patient presented with fever, widespread lymphadenopathy and pleuropulmonary involvement and responded promptly to multiagent doxorubicin-based chemotherapy. This was followed by high-dose chemotherapy and allogeneic bone marrow transplantation and the patient remains in remission more than 36 months post transplant. This case report suggests that myeloma simulating lymphoma may be a chemosensitive and potentially curable myeloma variant.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1996

The effect of interferon beta-1b on lymphocyte-endothelial cell adhesion.

Interferon beta-1b (IFN beta-1b) (Betaseron) has been recently approved for treatment of multiple sclerosis (MS), an inflammatory demyelinating disease of the central nervous system (CNS). The mechanism of action of IFN beta-1b is not understood, but its effect in reducing gadolinium enhanced MRI lesions suggest an effect at the blood brain barrier (BBB). Thus the objective of this study is to examine the effect of IFN beta-1b treatment of endothelial cells (EC) on lymphocyte-EC adhesion, and on the expression of the adhesion molecules (AM) ICAM-1, VCAM and E-selectin induced by IFN-gamma, TNF-alpha, or IL-1 beta. Primary cultures of human umbilical vein EC (HUVEC) were used which under basal conditions expressed low levels of ICAM-1 but not VCAM or E-selectin. IFN beta-1b (1-1000 IU/ml) had minimal effect on basal expression of AM on HUVEC, but AM could be substantially upregulated by IFN-gamma, IL-1 beta or TNF-alpha which was associated with a parallel increase in lymphocyte-EC adhesion. The effect of IFN beta-1b on AM expression induced by IFN-gamma, IL-1 beta or TNF-alpha was slightly additive, and was associated with a modest increase in lymphocyte-EC adhesion. In contrast TGF-beta, shown previously to downregulate lymphocyte-EC adhesion, inhibited this adhesion in our experiments. It is concluded that IFN-beta does not downregulate the inducible expression of ICAM-1, VCAM or E-selectin on HUVEC and does not inhibit the adhesion of lymphocytes to HUVEC. These findings have implications on the mechanism of action of IFN beta-1b in MS.

Cell Adhesion↗
PubMed1996

Therapy of untreated acute myeloid leukemia in the elderly: remission-induction using a non-cytarabine-containing regimen of mitoxantrone plus etoposide.

PURPOSE: The University of Manitoba Adult Acute Leukemia Study Group sought to examine the safety, efficacy, and impact on quality of life of a non-cytarabine-containing remission-induction regimen followed by intermediate-dose cytarabine (IDARA-C) postremission therapy for the management of untreated acute myeloid leukemia (AML) in patients age 60 to 80 years. PATIENTS AND METHODS: Eligible patients received mitoxantrone 10 mg/m2 and etoposide 100 mg/m2 on days 1 to 5. Complete remitters received a single course of cytarabine 0.5 mg/m2 every 12 hours on days 1 to 6. Cytogenetic and immunophenotyping studies were performed at diagnosis and were examined for prognostic importance. The Functional Living Index-Cancer (FLI-C) was used in the longitudinal assessment of quality of life. RESULTS: A total of 37 (55%) of 67 eligible patients achieved remission, 34 (92%) of whom did so with a single course. The induction mortality rate was 12%. The median disease-free and overall survival times were 8.4 and 9.2 months, respectively. CD34 stem-cell phenotype, poor performance status, and high cytogenetic complexity score were independent covariates of failure to achieve remission. Very complex karotype combined with CD34 stem-cell phenotype to predict induction death in 67% of cases (P = .0003). Cytotoxic therapy-related gut epithelial damage was maximal during weeks 2 and 3 of therapy. Complete remitters and partial responders exhibited significantly improved global FLI-C scores following completion of therapy. CONCLUSION: Mitoxantrone plus etoposide was an effective and well-tolerated first-line induction regimen for AML in the elderly that should be studied further in comparison to the standard cytarabine/anthracycline-based therapy.

Acute Disease↗
PubMed1995

In vivo inhibition of oestrone sulphatase and dehydroepiandrosterone sulphatase by oestrone-3-O-sulphamate.

Many tumours in endocrine-sensitive tissues, such as the breast and endometrium, are hormone-dependent and the hydrolysis of oestrone sulphate (EIS) to oestrone by oestrone sulphatase (EI-STS) is a major source of oestrogen in such tumours. Oestrone-3-O-sulphamate (EMATE) has been shown to be a potent EI-STS inhibitor in vitro, and in this study its ability to inhibit enzyme activity in vivo was examined. EMATE was initially administered to female rats for 7 days, after which liver EI-STS activity was measured. As EMATE also inhibits a related sulphatase in vitro, dehydroepiandrosterone sulphatase (DHA-STS), its effect on the activity of this enzyme in vivo was also investigated. DHA-STS has a pivotal role in regulating the synthesis of another steroid with potent oestrogenic properties, androstenediol. Administration of EMATE almost completely inhibited liver EI-STS (99%) and DHA-STS (99%) activities and was active when given by the oral or subcutaneous routes. After a single dose of EMATE or following the cessation of multiple doses for 10 days, liver EI-STS activity remained inhibited ( > 95%) for up to 7 and 10 days, respectively. Other compounds, such as 4-hydroxytamoxifen and the "pure" antioestrogen ICI 182,780, which are reported to inhibit EI-STS activity in vitro, did not inhibit activity in vivo. In a preliminary study, EMATE, when injected over a 12-day period, effectively reduced the growth of EIS-stimulated nitrosomethyl-urea-induced mammary tumours in ovariectomised rats and inhibited tumour sulphatase activity in treated animals.

Animals↗
PubMed1995

Inactivation of steroid sulfatase by an active site-directed inhibitor, estrone-3-O-sulfamate.

Steroid sulfatases are responsible for the hydrolysis of 3beta-hydroxy steroid sulfates, such as cholesterol and pregnenolone sulfate, and have an important role in regulating the synthesis of estrogenic steroids, from estrone sulfate and dehydroepiandrosterone sulfate, in endocrine-dependent tumors. Although little is known about the mechanism by which the sulfate group is removed from a steroid nucleus, an active site-directed sulfatase inhibitor has been developed. This inhibitor, estrone-3-O-sulfamate (EMATE), was synthesized by treating the sodium salt of estrone with sulfamoyl chloride. This compound inhibited not only estrone sulfatase but also dehydroepiandrosterone sulfatase activity in placental microsomes and in intact MCF-7 breast cancer cells. Pretreatment of MCF-7 cells or placental microsomes with EMATE, followed by extensive washing or dialysis indicated irreversible inhibition. This was confirmed by showing that EMATE inhibited estrone sulfatase activity in placental microsomes in a time-, concentration-, and pH-dependent manner. The enzyme is protected from inactivation by estrone sulfate, which is also consistent with active site-directed inhibition. EMATE is proposed to inactivate estrone sulfatase by irreversible sulfamoylation of the enzyme. Maximum enzyme activity was detected at pH 8.6, and the maximum rate of enzyme inactivation by EMATE also occurred at this pH. The pKa values of the enzymatic reaction and pKa of inactivation were 7.2 and 9.8, providing evidence that two active site residues are being modified by EMATE. As the phenolic pKa of tyrosine (9.7) and the pKa of histidine will allow the roles that (6.8) are similar to the pKa values of inactivation, these amino acid residues may play a role in the catalytic mechanism.(ABSTRACT TRUNCATED AT 250 WORDS)

Arylsulfatases↗
PubMed1995

The role of cytokines and sulphatase inhibitors in regulating oestrogen synthesis in breast tumours.

Synthesis of oestrogens within breast tissues makes an important contribution to the high concentrations of oestradiol which are found in breast tumours. The activities of the enzymes involved in oestrogen synthesis, i.e. the aromatase, oestradiol dehydrogenase (E2DH) and oestrone sulphatase (E1-STS), can be stimulated by several growth factors and cytokines. As it is possible that some of these factors may be derived from cells of the immune system (macrophages and lymphocytes), the effects of basic fibroblast growth factor (bFGF) and interleukin-2 (IL-2), which are produced by these cells, on E2DH activity was examined in MCF-7 cells. Treatment of these cells with bFGF resulted in a dose-dependent increase in E2DH reductive activity whereas IL-2 was inactive at the concentration tested. To obtain further evidence that factors produced by macrophages and lymphocytes can modulate the activities of enzymes involved in oestrogen synthesis, conditioned medium was collected from these cells and found to stimulate both E1-STS and E2DH activities. In addition to understanding the control of oestrogen synthesis in breast tumours an inhibitor to block the synthesis of oestrone via the oestrone sulphatase pathway was developed. Oestrone-3-O-sulphamate (EMATE) is a potent, irreversible, inhibitor of E1-STS. A single dose of EMATE (10 mg/kg) inhibited tissue E1-STS activity in rats by more than 95% for up to 7 days, indicating that this compound may have considerable therapeutic potential for the treatment of breast cancer. Evidence is also reviewed that another steroid sulphatase, dehydroepiandrosterone sulphate sulphatase, may have a crucial role in regulating cytokine production and that this may indirectly control tumour oestrogen synthesis.

Breast Neoplasms↗
PubMed1994

Conformations and structure studies of sugar lactones in the solid state. Part II. The molecular structure of alpha-D-glucosaccharino-gamma-lactone: 2-C-methyl-D-ribo-pentono-1,4-lactone.

The crystal structure of 2-C-methyl-D-ribo-pentono-1,4-lactone (alpha-D-glucosaccharino-gamma-lactone, 1) has been determined by single-crystal X-ray diffraction. The crystals are orthorhombic, space group P2(1)2(1)2(1) with a = 7.7429(6), b = 8.3373(7), c = 11.3258(7) A, V = 731.1(2) A3 (CuK alpha, lambda = 1.54184 A), mu = 10.82 cm-1, Dc = 1.473 g cm-3, and Z = 4. The structure was refined to R = 0.0307 and Rw = 0.0424 for 876 observed reflections. Compound 1 has the D-ribo configuration, in agreement with an earlier deduction from chemical evidence. The lactone ring adopts the 3T2 conformation, with puckering parameters psi = 279.8(9) degrees and q = 0.32(5) A. The orientation of the methyl group about the C-2-C-3 bond is gauche-trans, with the C-6-C-2-C-3-O-3 and C-6-C-2-C-3-C-4 torsion angles being -81.3(2) degrees and 154.7(1) degree, respectively. The molecules are linked in the crystal in a two-dimensional intermolecular hydrogen bonding network that involves all hydroxyl groups as well as the carbonyl oxygen atom.

4-Butyrolactone↗
PubMed1994

Development and validation of the Stirling Eating Disorder Scales.

The development and reliability/validity check of an 80-item, 8-scale measure for use with eating disorder patients is presented. The Stirling Eating Disorder Scales (SEDS) assess anorexic dietary behavior, anorexic dietary cognitions, bulimic dietary behavior, bulimic dietary cognitions, high perceived external control, low assertiveness, low self-esteem, and self-directed hostility. The SEDS were administered to 82 eating disorder patients and 85 controls. Results indicate that the SEDS are acceptable in terms of internal consistency, reliability, group validity, and concurrent validity.

Adult↗
PubMed1994

The hydrolysis of oestrone sulphate and dehydroepiandrosterone sulphate by human steroid sulphatase expressed in transfected COS-1 cells.

Whether the same or distinct steroid sulphatases (STS) are involved in the hydrolysis of alkyl and aryl steroid sulphates remains controversial. We have examined the ability of a placental steroid sulphatase to hydrolyse oestrone sulphate and/or dehydroepiandrosterone sulphate (DHA-S) by expressing the enzyme in COS-1 cells. Using either intact cells or broken cell preparations, the expressed sulphatase was found to hydrolyse both oestrone sulphate and DHA-S. The catalysis of oestrone sulphate and DHA-S by the expressed sulphatase was almost completely abolished by the steroid sulphatase inhibitor, oestrone-3-O-sulphamate. It is concluded that both alkyl and aryl steroid sulphates can be hydrolysed by the same steroid sulphatase.

Animals↗
PubMed1994

Phenotypically defined memory CD4+ cells are not selectively decreased in chronic HIV disease.

Simultaneous measurements of phenotypically defined memory CD4+ cells and in vitro proliferation to three recall antigens (Ags; tetanus toxoid, influenza, and Candida albicans) were performed in 53 HIV-seropositive subjects and 39 HIV-seronegative controls. The results indicate that the low proliferative responses to recall Ags of those who were HIV infected could be partly, but not fully, explained by a decrease of phenotypically defined memory CD4+ cells. This is, to our knowledge, the first report of experiments that simultaneously measured memory CD4+ cell numbers and function and then examined whether the low responses observed in seropositive subjects could be explained by low numbers of phenotypically defined memory CD4+ cells. A central finding of the study, which argues against prevailing dogma, was that within the CD4+ lymphocyte population, the proportion of cells displaying the memory phenotype was not selectively decreased in HIV-seropositive subjects as compared with the proportion of these cells in seronegative homosexual controls. An entirely new finding of the study was that AIDS patients, many of whom were unresponsive to all three recall Ags tested, actually had a significant increase in the proportion of CD4+ cells with the memory phenotype, and this fraction approached 100% in subjects with CD4+ cell numbers that were near zero. A final observation of the study, possible because some patients were on zidovudine (ZDV), was that there was no evidence that ZDV treatment led to an increased proliferative response to recall Ags in vivo. An in vitro study also found no effect of ZDV, dideoxycytidine (ddC), or azido-dideoxyuridine (AZU) on proliferative responses to recall Ags.

CD4-Positive T-Lymphocytes↗
PubMed1993

Comparison of eating disorders and other dietary/weight groups on measures of perceived control, assertiveness, self-esteem, and self-directed hostility.

Anorexic and bulimic patients were compared to obese dieters, nonobese dieters, and normal controls on measures of perceived control, assertiveness, self-esteem, self-directed hostility, and psychiatric caseness. The anorexic and bulimic groups both scored significantly differently in the expected direction from the other three groups on all measures. There were no significant differences between the anorexic and bulimic groups and in turn, no significant differences among the obese, nonobese dieters, and normal controls. Results are in keeping with the notion that perceived control, low assertiveness, low self-esteem, and self-directed hostility are characteristics of eating disorder patients that differentiate them from individuals who display dietary/weight features, as well as from normal controls.

Adult↗
PubMed1993

Bovine internal mammary artery as a conduit for coronary revascularization: long-term results.

Graft patency after coronary artery bypass grafting depends largely on the choice of conduit. Because an increasing number of patients have insufficient or poor-quality autologous material, there is a need for a suitable synthetic graft that is readily available and easy to handle and that has good long-term patency. Early results suggest that the bovine internal mammary artery graft may meet these criteria. We have used a total of 26 such grafts in 18 patients. Postoperative angiography has been performed in 19 grafts in 14 patients, 3 to 23 months after operation; of these grafts, 3 are currently patent (15.8%, compared with 85.7% and 75.0% patency for native internal mammary artery and saphenous vein grafts in the same patients). We report the results of clotting studies and an analysis of lipid status. These patients do not, however, appear to represent any atypical group, either in terms of coagulopathy, native coronary artery size, or the type of vessel disease. Nevertheless, our poor results contrast markedly with the early enthusiasm reported from other centers.

Aged↗
PubMed1993

Apical hypertrophic cardiomyopathy presenting as acute subendocardial myocardial infarction.

Two patients with apical hypertrophic cardiomyopathy presented with angina at rest and giant inverted T waves in precordial leads on the electrocardiogram. At cardiac catheterisation one patient had mild coronary artery disease, the other had normal coronary arteries. In both, there was a systolic pressure gradient between the apex and main left ventricular cavity exceeding 100 mmHg. The presence of rest angina with the electrocardiographic findings lead to a mistaken, initial diagnosis of acute subendocardial myocardial infarction.

Angina Pectoris↗
PubMed1993

Pharmacokinetics of recombinant human interferon-beta ser in healthy volunteers and its effect on serum neopterin.

The pharmacokinetics of and biologic response modification by recombinant human interferon-beta ser (rIFN-beta ser) were evaluated in 12 healthy male volunteers. Subjects received a single intravenous (iv) injection of 90 x 10(6) IU of rIFN-beta ser followed by a single or eight consecutive daily 90 x 10(6) IU subcutaneous (sc) doses. Blood samples collected after the iv, first sc, and last sc doses and prior to each sc dose were assayed for interferon antiviral activity and the interferon-inducible marker neopterin. Following iv administration, serum interferon concentrations generally declined biexponentially, with a mean serum clearance of 0.76 +/- 0.28 L/hr-kg, a mean steady-state volume of distribution of 2.88 +/- 1.81 L/kg, and a mean terminal half-life of 4.29 +/- 2.29 hr as determined by noncompartmental analysis. Following sc administration, absorption of rIFN-beta ser was prolonged, with serum concentrations generally below 100 IU/mL. No accumulation of rIFN-beta ser in serum was noted after eight daily sc injections. In contrast, serum neopterin levels did not increase above baseline levels until 12 hr after iv dosing and 24 hr after sc dosing. The mean increase in serum neopterin at 24 hr post iv injection was significantly greater than that at 24 hr post sc dosing.

Adult↗
PubMed1992

The use of transoesophageal echocardiography for detecting early recurrence of atrial myxoma.

A comparison between praecordial and transoesophageal cross-sectional echocardiography was undertaken in the follow-up of 14 patients who had previously undergone surgical excision of atrial myxoma. The mean interval between surgery and follow-up was 39 months. Evidence of recurrent tumour was seen in two patients by transoesophageal echocardiography but went undetected in one of these using the praecordial approach. Clear visualisation of the atria and interatrial septum was possible in all remaining cases using transoesophageal echocardiography and this allowed confident exclusion of tumour recurrence. Using praecordial echocardiography, technically inadequate studies meant that this was not possible in 4 patients. The significant late recurrence rate of excised atrial myxomas, emphasises the need for serial, postoperative echocardiographic studies. Praecordial echocardiography may be unreliable in the detection of recurrent atrial myxoma in its early stages and for this reason transoesophageal echocardiographic follow-up is justified in high risk patients.

Echocardiography↗
PubMed1992

Oesophageal motility, luminal pH, and electrocardiographic-ST segment analysis during spontaneous episodes of angina like chest pain.

The relation between oesophageal motility, luminal pH, and spontaneous pain events in 47 patients with recurrent angina like pain and normal coronary arteries was investigated. Preliminary investigation by conventional station pull through manometry (SPTM), was followed by a 24 hour period of ambulatory oesophageal motility and luminal pH monitoring. Computerised analysis of motility and pH data recorded during chest pain was then compared with pre-elected control samples taken before and after symptoms. Concurrent real time electrocardiographic (ECG)-ST segment analysis was performed to catalogue any ECG-STT wave changes indicative of myocardial ischaemia. SPTM showed a high group percentage incidence of simultaneous contractions (mean (SD) 11.1 (2.3)%) and a raised lower oesophageal sphincter tone (57.4 (15.2) mm Hg). During ambulatory monitoring, 35 patients experienced one or more episode of angina, providing a total of 59 pain events, although no significant change in group motility and reflux parameters peculiar to episodes of chest pain were found. Ischaemic ECG changes were detected in 10 (21%) patients, but were accompanied by pain in only two. Independent analysis of the ECG traces corresponding to these purported ischaemic ECG events determined them unequivocal in three patients and probable in a further two. No apparent correlation was noted, however, between these ECG events and corresponding patterns of motility or reflux.

Adult↗