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D A Rew

Publications and source records attributed to D A Rew.

At least 73 records · Page 4Linked to original sources
PubMed1995

Pan cycle expression of proliferating cell nuclear antigen in human colorectal cancer and its proliferative correlations.

Proliferating cell nuclear antigen (PCNA) is a key cycle regulatory protein of known structure and function that also has an important role in DNA repair, its use as a marker of proliferation can be assessed directly using a thymidine analogue in suitably labelled pathological material. Following optimisation studies, a quantitative and cell cycle phase-specific analysis of PCNA expression in fresh biopsies from 50 colorectal tumours (Series A) was undertaken using dual parameter flow cytometry (FCM). For comparison, quantitative histometric studies of PCNA expression were undertaken on 50 archival bromodeoxyuridine (BrdUrd) labelled colorectal tumours (Series B). In FCM assays, PCNA-specific fluorescence was displayed throughout the cell cycle in both cells and nuclei under all preparation conditions, but to a very variable extent. The mean PCNA labelling index ranged from 38.7% to 53.0% according to the method of cell extraction used. In the 27 diploid tumours in Series A, the median PCNA LI in G0/G1 was 71.5% (range 27.0-90.6%), in S it was 10.5% (3.3-29.5%), and in G2/M it was 17.4% (5.7-43.5%). In the histometric studies of Series B tumours, the mean [S.D.] PCNA labelling index (LI) was 38.8 [9.8]%, compared with the BrdUrd (histometric) LI of 21.1 [9.0]%. The BrdUrd LI measured by FCM was 12.4 [6.5]%. PCNA-PC10 is expressed throughout the cell cycle in human colorectal tumour biopsies, which is in keeping with the range of DNA repair, synthesis, and regulatory functions that it is now recognised to perform throughout the cell cycle.

Bromodeoxyuridine↗
PubMed1994

Significance of aneuploidy.

Aneuploidy is a state of abnormal and highly variable DNA and chromosome content found in both hereditary disorders and human malignancy. For two decades flow cytometry has allowed a wide-ranging survey of aneuploidy in clinicopathological series. Although up to 75 per cent of all tumours analysed display aneuploidy, its value as a clinical marker of biological aggressiveness is still uncertain. New technologies promise to reveal more precisely the genetic and subchromosomal changes that constitute aneuploidy and contribute to the malignant phenotype in human tumours.

Aneuploidy↗
PubMed1994

Pancreatic pseudocyst should be treated by surgical drainage.

This debate reviews the arguments in favour of surgical or non-surgical techniques for the management of pancreatic pseudocysts. Surgery provides definitive management and has a low risk of recurrence; pancreatic resection may be required to achieve this. Surgical treatment of pancreatic pseudocyst is safe, with little morbidity and low mortality, and surgical drainage allows biopsy of the cyst wall to exclude a cystic neoplasm of the pancreas. Percutaneous techniques have the advantage of low morbidity and mortality, with less discomfort to the patient than a surgical incision. In selected patients, a good result can be anticipated. The balance of the evidence suggests that both approaches are useful in different patients. Pseudocyst management should be tailored to each individual case.

Acute Disease↗
PubMed1993

Study of the proliferation in human gastric mucosa after in vivo bromodeoxyuridine labelling.

Studies to measure human gastric crypt or gland cell proliferation may have a number of practical clinical applications in relation to both benign and malignant gastric conditions. Bromodeoxyuridine (BrdUrd) labels human gastric mucosal cells in the S phase. Computer aided data analysis of labelled mucosa allows static proliferative indices to be estimated, including the crypt labelling index (LI), the peak labelling position, the distribution of labelled cells and indirectly the crypt growth fraction. Multiparameter flow cytometric analysis of labelled nuclei allows the S phase duration (Ts) of mucosal cells to be estimated. Specimens of histologically normal gastric body (GB, n = 16) and antral mucosa (GA, n = 10) were obtained from 25 patients with gastric carcinomas who received a bolus dose of 250 mg BrdUrd between 3.0 and 15.7 hours before surgery. Tissue sections were stained by an immunohistochemical method and subjected to detailed counting of up to 50 longitudinal crypts per specimen. The total crypt labelling index was calculated by a grid counting method. A significant difference existed between the proliferative compartments of gastric antral and body mucosa measured by a number of criteria. The median lengths of the crypts were 137 cells (GB) and 188 cells (GA). The median peak labelling positions were cell 26 (GB) and cell 61 (GA) from the crypt orifice. The mean crypt labelling indices were 2.8% (GB) and 4.8% (GA). The mean Ts of GA cells was 7.7 hours and of GB cells was 10.8 hours.

Adult↗
PubMed1992

Proliferation indices of invasive breast carcinomas after in vivo 5-bromo-2'-deoxyuridine labelling: a flow cytometric study of 75 tumours.

In vivo labelling of human breast tumours with 5-bromo-2'-deoxyuridine and analysis of proliferation by multiparameter flow cytometry is a new tool by which the labelling index, S phase duration (TS) and potential doubling time (Tpot) of the tumour can be estimated. Tumour specimens from 75 patients with invasive breast carcinoma were studied. Six tumours could not be analysed, and the TS and Tpot values could not be calculated for a further 18. The median labelling index (n = 69) was 4.2 per cent. The median TS (n = 51) was 8.7 h and the median Tpot (n = 51) was 8.2 days. The median intra-assay coefficient of variation for determination of the labelling index was 0.29 in five tumours. There were no significant differences in the total labelling index, TS or Tpot when patients were stratified according to lymph node status, tumour size, tumour grade or menopausal status.

Adult↗
PubMed1992

Measurement of in vivo proliferation in human colorectal mucosa using bromodeoxyuridine.

In vivo bromodeoxyuridine (BrdUrd) labelling of the human large bowel was performed and a detailed histochemical localisation of label in sections of crypts was undertaken using a monoclonal antibody to BrdUrd containing DNA. Flow cytometric studies on extracted nuclei were also performed (data presented elsewhere). The average crypt in the human large bowel (excluding the rectum) was 82 cells in height and 41 cells in circumference, with a total of about 2000 cells (assuming a topographical correction factor of 0.6). Ten per cent of the cells were replicating their DNA--that is, were in the S phase of the cell cycle--and 0.4% were in mitosis. The median position for the labelling index versus cell position frequency plot is at the 20th cell position--at a quarter of the crypt height. The lower and upper limits of the cell proliferation are given by the 5th and 95th percentiles at cell positions 4 and 43 respectively. The peak labelling index is about 30% and it occurs at cell position 15. The labelling index at the crypt base, the probable stem cell zone, is about 14%, suggesting that these cells have a longer cell cycle. Taking a value of 8.6 hours for the duration of the S phase (deduced from the flow cytometric data) and assuming a growth fraction of 1.0 for the mid-crypt, these data provide an estimate of about 30 hours for the cell cycle time. The rectal crypts are about the same size but contain about 30% fewer S phase cells. The data also yielded a per cent BrdUrd labelled mitosis curve.

Aged↗
PubMed1992

Proliferation in human gastrointestinal epithelium using bromodeoxyuridine in vivo: data for different sites, proximity to a tumour, and polyposis coli.

The distribution of DNA synthesising cells in the crypts of the epithelium in human small and large bowel after injection of bromodeoxyuridine into patients has been studied in relation to the position of the cells in the crypt using immunohistochemistry. Different sites of normal epithelium have been studied. The ileum has a shorter crypt and a very significantly smaller total cell population size. However, it has similar peak labelling index (LI) values to the colon, while the rectum has a lower peak LI value. The mean position of the label occurs at the 17th cell position in the ileum and at about the 22nd position in both the colon and rectum. The overall mean LI is significantly higher in the ileum at 17.8%, intermediate in the colon at 10.3%, and lowest in the rectum at 8.5%. There is thus an inverse relation between the likelihood of developing a tumour and the rate of cell proliferation as measured by the LI. Assuming a value of 8.6 hours for the duration of S, the data suggest that the cell cycle time in the mid crypt region is about 30 hours for the ileum and colon and about 37 hours for the rectum. Samples taken adjacent (within 1 cm) to a tumour show a general dampening of proliferative activity at all cell positions compared with samples taken more than 5 cm from a tumour. This is illustrated by the average LI, which is about 5.4% in the colon adjacent to a tumour compared with 10% distant; comparable values for the rectum are 4.6% and 8.5%. Samples taken from two patients with polyposis coli show distributions with a significant difference in skewness compared with normal colon and a general shifting of the distribution to the right, that is to higher cell positions. There is a significant increase in the mean cell position and the position of the peak LI in the polyposis coli samples.

Adenomatous Polyposis Coli↗
PubMed1992

A comparison of in vivo cell proliferation measurements in the intestine of mouse and man.

Using tritiated thymidine (3HTdR) labelling in vivo in the mouse we have determined the labelling index (LI%) at each cell position along the sides of sections of crypts in the small and large bowel. We have compared LI versus cell position frequency plots obtained in this way with those obtained using bromodeoxyuridine (BrdUrd) in vivo in the small intestine. Both thymidine analogues give identical patterns and similar levels of labelling: for example, the overall LI is 29.1% after 3HTdR and 34.7% after BrdUrd in the mouse ileum. Similar data have been obtained following in vivo labelling in humans with BrdUrd prior to gastrointestinal surgery for cancer and in mouse colon following 3HTdR labelling. Comparisons between the mouse and human data show that the spatial distribution of label within the crypts occurs at the same relative positions in the two species. However, the intestinal crypts are between 2-fold and 4-fold larger, particularly in their length, in the human: for example, 250 and 450 cells per crypt for ileum and 590 and 2000 cells per crypt for the colon in mouse and human respectively. The absolute value of the maximum LI in the mouse small intestine (56.5%) is higher than it is in the human (26.3%). However, the patterns of proliferation are similar in the two species under steady-state conditions.

Animals↗
PubMed1991

Proliferation characteristics of human colorectal carcinomas measured in vivo.

The cell proliferation kinetics of 100 human colonic and rectal adenocarcinomas have been studied in vivo by bromodeoxyuridine infusion and multiparameter flow cytometry. A total of 97 patients, three with synchronous tumours, consented to receive a single bolus dose of 250 mg between 2.4 and 16 h before curative or palliative surgery. By this method, the ploidy pattern, the total and aneuploid labelling indices (LI), the S phase duration (Ts) and the potential doubling time (Tpot) can be estimated. Of the tumours 48 were diploid and 52 were aneuploid. The mean and median total LI of 100 tumours were 9.0 per cent (range 0.7-22.2 per cent). The mean aneuploid LI was 12.1 per cent (median 12.0 per cent, range 2.0-25.5 per cent), and was significantly higher than the total LI (P = 0.01). The labelling index alone is not a sufficient indicator of proliferation, because the Ts also varies within and between tumours. The intertumour range of the Ts varied from 4.0 to 28.6 h. The mean was 14.1 h and the median was 13.1 h. The mean Tpot was 5.9 days (median 3.9 days) with a range of 1.7-21.4 days. No correlation was found between any kinetic parameters and the Dukes' classification or histological classification. The correlation between proliferation and prognosis will be established in due course.

Adenocarcinoma↗
PubMed1991

c-myc protein product is a marker of DNA synthesis but not of malignancy in human gastrointestinal tissues and tumours.

c-myc is a conserved cellular gene. The gene product is a nuclear-bound 62,000 molecular weight phosphoprotein (p62c-myc). Although p62c-myc levels have been measured in colorectal cancers, little is known about the expression of the protein in upper gastrointestinal tumours and tissues. Studies were performed on tumour and mucosal specimens from 87 patients with colorectal cancer, from two with polyposis coli, from six with squamous oesophageal carcinomas and from 18 with gastric carcinomas. The mean p62c-myc content was measured in units of fluorescence in the G1 diploid and G2 diploid peaks of the cell cycle by multiparameter flow cytometry using the 6E10 antibody. The nuclear p62c-myc content increased with DNA synthesis in tumours and mucosa. G2 levels of p62c-myc were higher in glandular mucosa than in adenocarcinomas. No differences in peak nuclear c-myc expression were found in relation to histological grade or to anatomical site of colorectal tumours. There was a broadly inverse relationship between G2 p62c-myc levels in tumours and mucosa and their in vivo 5-bromo-2'-deoxyuridine labelling indices. Nuclear p62c-myc levels are cell cycle related but the protein has not been shown to be a marker of increased tissue proliferation or of gastrointestinal malignancy. The reduction of the nuclear p62c-myc content of many adenocarcinoma cells compared with glandular mucosa cells suggests that reduced synthesis or nuclear retention of the normal protein may be a factor in the development of gastrointestinal adenocarcinomas, although the mechanism by which this may occur is not clear.

Adenocarcinoma↗
PubMed1991

Measurement of in vivo urological tumour cell kinetics using multiparameter flow cytometry. Preliminary study.

The in vivo labelling of urological tumour cells using the S phase marker bromodeoxyuridine (BRdU) for histochemical studies is reported. The use of multiparameter flow cytometry (FCM) with BRdU labelling to study tumour proliferation offers significant advantages. It provides simultaneous measurements of the DNA ploidy (DI), the duration of the S phase (Ts), the potential doubling time (Tpot) and the total and aneuploid tumour labelling indices (LI) from a single specimen. Heterogenous tumour cell populations can be measured with high sensitivity. We report a preliminary study to evaluate the method in the measurement of the kinetics of transitional cell carcinoma of the bladder (TCCB). Nineteen patients with TCCB, 1 with leukoplakia of the bladder, 2 with renal carcinoma, 1 with prostatic carcinoma and 1 with a squamous carcinoma of the penis were studied. Of the bladder tumours, 3 were aneuploid, DI = 1.32, 1.58 and 1.89. BRdU uptake was detected in all tumours. The median LI was 1.5% (range 0.5-10.0). In 15/19 tumours the labelling profile was satisfactory for calculation of the Ts and Tpot. The median Ts was 6.2 h and the median Tpot was 17.1 days. This study demonstrates that measurement of multiple parameters of urological tumour proliferation in vivo is possible. These parameters require further assessment as indices of biological aggressiveness and clinical prognosis.

Aneuploidy↗
PubMed1989

Assessment of the safety of regular DDAVP therapy in primary nocturnal enuresis.

A group of 7 patients with refractory primary nocturnal enuresis on long-term DDAVP therapy (mean 13 months) were submitted to a standard water deprivation test in conjunction with a hormone profile and routine haematological and biochemical investigations. No abnormalities were demonstrated, which suggests that the drug is safe in this clinical situation.

Adolescent↗