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J Philips

Publications and source records attributed to J Philips.

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

Fine-needle aspiration biopsy of parotid lesions: comparison with frozen section.

BACKGROUND: Opinions vary as to the necessity for fine-needle aspiration biopsy (FNAB) in parotid tumours. The present study reflects the experience gained over a 12-year period and shows the accuracy of a diagnostic FNAB, and improved results with experience. METHODS: Between 1983 and 1995, 201 parotid lesions were excised by one surgeon(AGP) and a prospective database was established. Fine-needle aspiration biopsy was performed prior to surgery in 195 lesions and frozen section was performed in 159 lesions. RESULTS: The FNAB was diagnostic in 129 (66%) specimens and its sensitivity for malignancy was 90% and specificity was 100% (excluding non-diagnostic FNAB, where there was insufficient cellular material for reliable diagnosis or where specific tissue diagnosis could not be given). The positive predictive value was 100% and the negative predictive value was 98%. Of interest, the positive predictive value of diagnostic FNAB for pleomorphic adenomas was 99%. A specific tumour diagnosis could not be made on the FNAB sample in 37 specimens; 11 of these lesions were histologically confirmed as malignant after excision. Frozen section was diagnostic in 144 specimens (91%). Its sensitivity for malignancy was 96% and specificity was 99%. The positive predictive value was 96% and negative predictive value 99%. A specific tumour diagnosis could not be made on frozen section in 15 specimens including six cases in which malignancy was finally reported. The positive predictive value of diagnostic frozen section for pleomorphic adenomas was 99%. CONCLUSIONS: A diagnostic FNAB is an accurate and useful tool in the management of parotid lesions. An FNAB diagnosis of pleomorphic adenoma obviates the need for frozen section. The performance of FNAB in parotid tumours does not in any way preclude the necessity of surgical removal of such lesions except in exceptional circumstances.

Adolescent↗
PubMed1996

Perturbation of nuclear architecture by long-distance chromosome interactions.

SUMMARY: Position-effect variegation (PEV) describes the stochastic transcriptional silencing of a gene positioned adjacent to heterochromatin. Using FISH, we have tested whether variegated expression of the eye-color gene brown in Drosophila is influenced by its nuclear localization. In embryonic nuclei, a heterochromatic insertion at the brown locus is always spatially isolated from other heterochromatin. However, during larval development this insertion physically associates with other heterochromatic regions on the same chromosome in a stochastic manner. These observations indicate that the brown gene is silenced by specific contact with centromeric heterochromatin. Moreover, they provide direct evidence for long-range chromosome interactions and their impact on three-dimensional nuclear architecture, while providing a cohesive explanation for the phenomenon of PEV.

Animals↗
PubMed1994

Correlation between cytopathological results and in situ hybridisation on needle aspiration biopsies of suspected African Burkitt's lymphomas.

Burkitt's lymphoma (BL) is a very high-incidence malignancy in sub-Saharan Africa, where it targets mainly young children. This lymphoma is closely associated with Epstein-Barr virus (EBV). Diagnosis of BL relies on clinical presentation as well as histological results obtained from biopsies. In this report, 66 new patients from Malawi (one of the southernmost African countries with high-incidence BL), suspected on clinical grounds to present with BL, had fine needle aspiration biopsies taken, smeared on slides and used for May-Grünwald Giemsa staining. Duplicate slides were independently assessed for EBV presence and expression by DNA-DNA and/or RNA-RNA in situ hybridisation (ISH), using respectively the repetitive viral BamHIW DNA fragment in a biotinylated probe and the small EBV-encoded RNA EBER I in a digoxigenin-labelled riboprobe. There was very good correlation between the various techniques in the diagnosis of the lymphomas, showing 67% of clinically suspect cases to be BL. Our report, presenting data on BL in Malawi, illustrates the usefulness of a simple aspiration biopsy in the diagnosis of this malignancy by Giemsa staining and also in both types of ISH.

Biopsy, Needle↗
PubMed1993

Characterization of a new human bladder cancer cell line, UCRU-BL-28.

A new human bladder cancer cell line, UCRU-BL-28 has been established and characterized from a relapsed, cisplatin resistant, grade II, stage T4 tumor. This line is tumorigenic in nude mice and reflects the pathology of the original tumor. The morphology, the expression of tumor-associated antigens and EGF receptors, and the ability to grow both in an anchorage independent manner and in the absence of serum is explored. The BL-28 line has 71-74XXY chromosomes, with del 5q, der(9) and i(19q). Further studies on the molecular basis of bladder cancer, chemosensitivity to cisplatin, growth factor production and tissue invasion are under way.

Biomarkers, Tumor↗
PubMed1992

Comparison of the expression of the seven ribosomal RNA operons in Escherichia coli.

We have compared the expression of the seven ribosomal RNA operons (rrn) of Escherichia coli and their responses to a variety of physiological and genetic perturbations. We used a set of rrn promoter fusion constructs in their native chromosomal positions to examine effects of chromosomal location on rrn operon expression and the same set of fusions on lambda lysogens to assay intrinsic promoter strengths independent of chromosome context. In its native chromosomal location, expression of the rrnH operon was significantly lower than expected. This effect was not attributable to weak promoter activity and was dependent on the growth medium. The rrnE operon had reduced promoter activity relative to the other ribosomal operons in minimal medium and thus appears to have abnormal growth rate regulation. The ribosomal RNA operons showed varied responses to amino acid starvation; expression of rrnD was inhibited most. There was only a slight increase in rrn transcription in response to a temperature shift (30 degrees C to 42 degrees C) and the differences between individual operons was very small. The rrnG operon showed a significantly lower response than the other ribosomal RNA operons to a depletion of the rrn transcription activator, Fis, and thus appears to have decreased Fis-mediated transactivation. Finally, the chromosomal fusion strains were used to study the effect on growth rate of inactivating each rrn operon. In fast growth conditions, loss of certain rrn operons caused subtle decreases in growth rate on complex medium.

Base Sequence↗
PubMed1991

Growth and metastasis of human bladder cancer xenografts in the bladder of nude rats. A model for intravesical radioimmunotherapy.

A potentially useful therapeutic approach to the treatment of human bladder cancer is intravesical therapy with radiolabelled monoclonal antibodies (MAbs). We have established an animal model to study this approach. Inoculation of cloned 2B8 cells derived from the human bladder cancer cell line, UCRU-BL-17, into the bladder wall of nude rats pre-irradiated with 900 rads, resulted in local tumour growth in 39/40 (97.5%) animals, with invasion or metastases to distant organs in 25% of cases. Both the bladder tumours and the metastases were morphologically similar to the original biopsy sample from which the cell line, UCRU-BL-17, was established. The cells were of human origin, as shown by expression of HLA antigens, Alu probing, and cytogenetic analysis. Preliminary studies indicated that i.p. injection of anti-human bladder cancer monoclonal antibody (MAb), BLCA-38, radiolabelled with either iodine 131 or samarium 153 (153Sm), resulted in tumour localisation, with tumour-to-blood ratios of 5.04 (131I), and 4.3 and 3.1 (153Sm) respectively. We now aim to examine the efficacy of the intravesical route for radioimmunotherapy in the nude rat model. This model will also serve for preclinical studies on the efficacy of systemically injected radioimmunoconjugates for control of metastatic growth.

Aged↗
PubMed1991

Prognostic significance of nuclear DNA content in phaeochromocytoma.

Nuclear DNA content of 27 phaeochromocytomas was measured by image analysis of thin sections and monolayer smears of nuclei extracted from thick sections (cytospins) using archival paraffin-embedded tissue blocks. Recurrence was assessed on the basis of clinical follow-up or urinary catecholamine levels. The mean follow-up was 5.0 years, with a range of 4 months to 15 years. Although it is not possible to differentiate accurately malignant tumours using DNA analysis, prediction of benign tumours is possible. Using thin sections, all tumours were benign when the percentage of cells with a DNA content of 2.5 c (2 c = diploid) was less than 40% and the DNA content of 5 c was less than 4%. Using the cytospin preparation, all diploid tumours were benign. Thus, patients with diploid tumours may be saved intensive long-term follow-up. Aneuploid and tetraploid tumours, however, continue to require careful lifelong follow-up.

Adolescent↗
PubMed1991

Comparison of image analysis and flow cytometric determination of cellular DNA content.

A good correlation (r = 0.94) was obtained between the DNA indices (DI) using flow cytometry and image analysis of nuclei cytospins extracted from paraffin wax embedded tumour sections. Some of the limitations and problems associated with image analysis which came to light included an unacceptably high coefficient of variation (CV) and a "left-shift" in the DI in most DNA histograms obtained when using image analysis of 5 microns sections. In contrast, the DNA histograms generated using image analysis of cytospun nuclei from paraffin wax blocks were of good quality and similar to those obtained using flow cytometry. Variability in Feulgen staining was common and an important source of error despite rigorous control of the staining technique. This could be overcome by using internal controls such as fibroblasts rather than external controls (rat hepatocytes) to determine the diploid DI with image analysis. A thorough understanding and appreciation of the methodological problems associated with image analysis and flow cytometric determination of DNA content is required before these methods find widespread clinical application.

Adrenal Gland Neoplasms↗
PubMed1990

Clonal analysis of a bladder cancer cell line: an experimental model of tumour heterogeneity.

The continuous cell line UCRU BL 17CL was derived from a human invasive bladder cancer and expresses elements of transitional, squamous and glandular differentiation. Nine clones of this line were established by limit dilution and have been extensively characterised. Only six of these clones grew subcutaneously in nude mice. Of these, three have exhibited local invasion, each in one of five implanted mice. Although all xenografts expressed transitional, squamous and glandular elements, different histological subtypes predominated within each clone. Only clones which grew in nude mice formed colonies in semi-solid medium, and each responded differently to the influence of medium that had been conditioned by the growth of UCRU BL 17CL, suggesting the possible secretion of a growth factor by these cells. The DNA content and lectin binding profiles of the clones also reflected the heterogeneity of the line. UCRU BL 17CL and the nine clones provide a unique model for the study of tumour heterogeneity, progression and differentiation, and the potential autocrine regulation of growth of bladder cancer.

Carcinoma, Transitional Cell↗
PubMed1990

High prevalence of antibiotic resistant Escherichia coli in faecal samples of students in the south-east of The Netherlands.

From December 1988 to March 1989 172 faecal samples from first and second year students at the University of Limburg, Maastricht, The Netherlands, were collected and analysed for the presence of Escherichia coli strains resistant to ampicillin, sulphamethoxazole, tetracycline, trimethoprim and nitrofurantoin. In addition, the antibiotic susceptibility (MIC) to these agents and six other compounds (i.e. aminoglycosides, nitrofurantoin, nalidixic acid and cephalothin) was determined. The prevalence of resistance of the samples analysed ranged from 86% (i.e. 148 out of 172) for sulphamethoxazole to 25% for trimethoprim. The prevalence figures for ampicillin, tetracycline and nitrofurantoin resistance were 76%, 47% and 29%, respectively. The percentages of the faecal samples with a high proportion of E. coli (greater than 50% of the total number of E. coli) resistant to ampicillin, tetracycline and sulphamethoxazole were 8%, 11% and 37%, respectively. For nitrofurantoin and trimethoprim the figures were 3% and 1%, respectively. Of the isolated E. coli (n = 797), 84% was resistant to ampicillin, 82% resistant to sulphamethoxazole. The lowest percentages (9%) were observed for both nalidixic acid and nitrofurantoin.

Ampicillin↗
PubMed1990

Routine use of intraoperative epicardial echocardiography and Doppler color flow imaging to guide and evaluate repair of congenital heart lesions. A prospective study.

Routine epicardial two-dimensional echocardiography, Doppler, and Doppler color flow imaging studies were performed before and after cardiopulmonary bypass in 328 patients undergoing operations for congenital heart disease. Ages ranged from 1 day to 59 years (mean 5.9 years); the smallest patient was 1.8 kg. Complete examinations were conducted in 3.6 +/- 1.7 minutes. Prebypass examinations demonstrated previously unappreciated details of anatomy in 60 patients (18%), which did not relate to whether catheterization had been performed, and they were believed to play a role in surgical planning in 143 patients (44%). Discovery of previously unrecognized features of anatomy increased the impact of echo-Doppler color flow imaging on operative planning by 2.5 times. After bypass, echo-Doppler color flow imaging disclosed unsuspected residual defects in 22 patients (7%) who were doing well clinically and enabled an attempt at immediate revision of the procedure. When ultimate clinical outcome was compared to postbypass findings of echo-Doppler color flow imaging, the presence of a residual defect, right or left ventricular dysfunction, or any concern with the heart by echo-Doppler color flow imaging appeared to serve as a predictor of unfavorable outcome (p less than 0.001 for each when compared with absence of these difficulties). Thus routine intraoperative echo-Doppler color flow imaging is useful in aiding the planning, conduct, and assessment of results in operations for congenital heart disease.

Cardiopulmonary Bypass↗
PubMed1989

Characterization of cell lines derived from a multiply aneuploid human bladder transitional-cell carcinoma, UCRU-BL-13.

A series of cultured cell lines (designated UCRU-BL-13) has been established from different serial passages of a multiply aneuploid human bladder transitional-cell carcinoma xenografted in nude mice. Serial passage of the xenografts in vivo and of the cell lines in vitro was accompanied by shifts in the tumor ploidy, with dominance of different major peaks. Despite this, the expression of tumor markers remained constant, and consistent chromosomal markers were observed both in the 8th xenograft passage and in a subline in tissue culture established over a year apart. Chromosomal numbers reflected the predominant aneuploid peaks observed; consistent numerical and structural changes included a marker derived from chromosome 1, 8p-, -10, 11q+, and 17q+. The cell line derived from the initial xenograft comprised a mixture of transitional, adenocarcinoma and squamous carcinoma cells in early passage, but adenocarcinoma cells were absent from later passages. The lines expressed the B-blood-group antigen, histocompatibility antigens, receptors for transferrin and EGF, and reacted with a series of monoclonal antibodies (MAbs) directed to malignant human epithelial cell lines. These lines provide a model for studying the evolution of tumor heterogeneity and drug resistance in bladder carcinoma exhibiting multiple aneuploidy.

Aneuploidy↗
PubMed1989

The stability and short-term fluctuation in serum oxytocinase activity in pregnancy.

Maternal serum samples obtained from 123 normal pregnant women between 28 and 40 weeks gestation were analysed for oxytocinase (EC 3.4.11.3) activity using s-benzyl-1-cysteine-4-nitroanilide as substrate. Oxytocinase activity was found to be stable at varying temperatures, with a mean co-efficient of variation of 5.0%. The short-term fluctuation of oxytocinase activity had a mean coefficient of variation of 3.6%. There is no suggestion of a "pulsatile" release of oxytocinae from its placental origin.

Aminopeptidases↗
PubMed1989

Detection of malignant cells in voided urine from patients with bladder cancer, a novel monoclonal assay.

A simple assay is described for detecting malignant cells in the voided urine from patients with transitional cell carcinoma of the bladder. Agarose-embedded urothelial cells from 24 biopsy-proven cancer patients and 10 controls were stained for surface immunofluorescence with four monoclonal antibodies reactive with human bladder cancer and three monoclonals reactive with blood group A. Reactivity was assessed by fluorescence microscopy. One antibody, BLCA-8 appeared to have particular diagnostic utility. Thus, 24.3 +/- 5.8 percent of outer layer and 27.0 +/- 4.6 percent of inner layer urothelial cells reacted with BLCA-8 in patient samples, compared to 2.9 +/- 1.0 and 0.8 +/- 0.5 percent of similar cells from control urines. BLCA-8 antigen expression was found to be relatively stable even after prolonged exposure to urine. In a comparison with conventional cytology, samples from 4/8 patients were considered positive by standard methods, whereas, 8/8 were BLCA-8 positive. This new technique may thus be a useful adjunct to conventional methods.

Animals↗
PubMed1988

Antigenic variation and macrophage infiltration of human bladder tumors xenografted into nude mice.

The presence of macrophages both within and around human bladder transitional cell carcinomas xenografted into nude mice has been examined using immunocytochemical staining. Nine different xenograft lines derived from bladder tumors of eight patients were stained for F4/80, MHC II and PGP-1 labelled cells. The results revealed considerable heterogeneity both within and between tumors. All of the tumors generated some macrophage response at the tumor periphery, and this was marked in two instances, UCRU-BL-13, passage 9 and UCRU-BL-17, passage 2. In only two tumors was there substantial penetration of the tumor epithelium by macrophages, though infiltrating Ia+, F4/80+, PGP-1+ cells were sometimes seen spreading along the base of the epithelial sheets. Three of the tumors were characterized by the presence of L3T4+ T lymphocytes at the invasion front. The presence of macrophages or lymphocytes either at the invasion front or within the tumors did not correlate with the pathological grade of the tumors. PGP-1 monoclonal antibodies also stained granulocytes, which were present within the tumor mass in UCRU-BL-15, passage 2, possibly reflecting the production by the tumor of G-CSF. In addition, the PGP-1 antibodies stained some of the bladder tumors cells themselves, and, in some cases, the interstitial structures within the tumors. The significance of this staining is not yet understood. The xenografted tumors will provide a useful model to examine the constraints on tumor therapy using macrophage activating stimuli.

Animals↗