DNA flow-cytometric analysis in colorectal cancer: a comparison of metastasizing and non-metastasizing tumours.

The most common cause of death in patients with colorectal cancer is metastatic liver disease. In order to identify patients at a high risk of developing hepatic secondaries from colorectal cancers, DNA content was measured in metastasizing colorectal primaries (Group I, n = 32) as well as in their subsequently resected liver secondaries and in sections of non-metastasizing colorectal cancers (Group II, n = 25). A modified interpretation system involving both a DNA index and percentage of cycling cells (those in S and G2 + M phases) was developed. DNA content was measured in paraffin-embedded sections by flow cytometry using internal controls (human peripheral blood mononuclear cells) and non-malignant tissue controls (19 patients with diverticular disease). In Group I there were significantly more tumours with both abnormal ploidy (aneuploid or abnormal tetraploid peak) and > 15% cycling cells compared with Group II (Chi-squared; P = 0.034). The combination of abnormal ploidy and > 15% cycling cells was superior to Dukes' classification for identifying metastasizing tumours (Logistic Regression; P = 0.047). However, it was not possible to discriminate between the two groups using either DNA ploidy or the percentage of cycling cells alone. The metastasizing colorectal cancers exhibited similar DNA ploidy characteristics and had a similar percentage of cycling cells compared with their liver metastases. These results suggest that tumour DNA ploidy plus the percentage of cycling cells may predict the development of liver metastases and thus survival in patients with colorectal cancer.

Background soil concentrations of phenolic compounds, chlorinated herbicides, PCDDs and PCDFs in the Melbourne metropolitan area.

During June and July 1990, surface soil samples were taken in the Melbourne metropolitan area and analysed for phenolic compounds, chlorinated herbicides, polychlorinated dibenzo-para-dioxins (PCDDs) and polychlorinated furans (PCDFs). A surface soil sample from a Werribee Farm Treatment Complex paddock, where cattle graze on land that is used for filtration of sewage, was also taken and analysed. No phenolic compounds or chlorinated herbicides were detected at the parts per billion detection limits in any of the samples. PCDDs and PCDFs were detected in both industrial and nonindustrial sectors of the Melbourne metropolitan area, as well as in effluent from Nufarm Limited, an agricultural chemicals manufacturer in Laverton North, in similar concentrations (toxic equivalents in the parts per trillion range). These concentrations were consistent with background levels identified in other major urban areas. There was no evidence of the Nufarm effluent fingerprint in any of the background soil samples analysed. The fingerprint profile of the sample taken from Werribee Farm, although showing traces of the Nufarm effluent fingerprint, was clearly distinct from that effluent fingerprint and consistent with the fingerprint identified in the background soils. The impact of the Nufarm effluent on the area, therefore, was considered insignificant.

A sensitive method for the detection of poly-A tails of mRNA using a biotin-labelled heteropolymer of dT:rA.

We have developed a highly sensitive non-radioactive in situ hybridization technique that enables us to study the production of mRNAs in tissues. As part of the validation procedure of our methods, we examined various methods of detecting poly-A RNA tails of mRNA. We have used three types of biotin-labelled probes complementary to poly-A sequences: a 25-mer poly-dT oligonucleotide, a polymer of dT, and a heteropolymer of dT:rA. All the probes had the same specificity of reactivity but the heteropolymer of dT:rA gave the strongest signals as visualized histochemically by the use of alkaline phosphatase as the detection enzyme. All the probes tested for poly-A detection showed reactivity. The poly-dT oligonucleotide showed a strength of signal comparable to published results. The biotinylated polymer of dT gave a stronger signal than that of the oligonucleotide, and the heteropolymer was the strongest of all. The strong signal seen with the heteropolymer probe is due to probe complexing during hybridization, in which additional binding between sense and antisense strands of the probe (i.e. poly-rA and poly-dT) amplifies the number of biotin molecules at the hybridization site; this strategy has been exploited by us as a means of visualizing low copy numbers of specific mRNAs.

Immunogold-silver staining by capillary action.

The authors have developed an improved method for immunogold-silver staining of paraffin sections. Using a manual capillary action staining system, they were able to simplify the technical aspects of the procedure, permitting rapid processing of large batches of slides with better reproducibility. Background staining was decreased by use of buffers containing a detergent. The use of a light-stable silver reagent permitted greater control of the enhancement stage. The method yielded a high degree of contrast with negligible nonspecific staining. Sensitivity was comparable to that obtained with conventional enzymatic immunostaining. However, the authors noted that trypsinization of sections was rendered unnecessary for those antigens for which such pretreatment was usually required, and the need for special fixatives could be eliminated. The method was also applicable to immunostaining of frozen sections. Immunogold-silver staining by capillary action deserves consideration as an alternative to existing immunohistochemical methods in diagnostic histopathology.

Herpes simplex and duodenal ulcer pathology.

An association between Herpes simplex Virus 1 (HSV-1) and duodenal ulcer disease has been suggested. Duodenal ulcers, like HSV-1 lesions, exhibit periodicity in recurrence. Several of the presently available anti-ulcer agents may have an antiviral action. Antibody titres in some studies have shown selective increases to HSV-1 in duodenal ulcer patients. The aim of this study was to determine whether a real association exists between HSV-1 and endoscopically proven duodenal ulcer or duodenal erosive disease. In a prospective study, 27 patients with either duodenal ulcer (16) or duodenal erosions (11) were studied in order to attempt isolation of HSV-1. Acute and convalescent sera were also taken and examined by an enzyme linked-immunoabsorbent assay system for antibody titres to HSV-1. Duodenal biopsies from a further 26 patients with duodenal ulcer or erosive disease were also examined retrospectively for HSV-1 by the immunoperoxidase technique. In no case of either duodenal ulcer or duodenal erosive disease was HSV-1 isolated by any of the above methods, nor was a relationship demonstrated by acute or convalescent HSV-1 antibody titres. Hence, this study does not support an association between HSV-1 and duodenal ulcer or erosive disease.

Meningioma with intracerebral hematoma.

A case of spontaneous intracranial hemorrhage associated with a meningioma is presented. Intracranial hemorrhage has been reported to be associated with meningioma in 45 cases. A comprehensive review of the subject is presented. The importance of the diagnosis of associated hemorrhage and subsequent surgical intervention is emphasized.

Hemangioendothelial sarcoma of the liver associated with long-term estrogen therapy in a man.

An elderly male patient developed a hemangioendothelial sarcoma of the liver after 9 years of stilbestrol therapy. The latter had been commenced as treatment for presumed carcinoma of the prostate. However, the latter diagnosis was never established, even at a subsequent autopsy, and presumably this was the reason he survived and had such a long course of treatment. It is suggested that there was a causal relationship between the estrogen therapy and the development of the sarcoma. This suggestion is supported by the fact that one similar case has been reported, and by recent evidence that hemangioendothelial sarcoma may be associated with the long-term use of androgenic-anabolic steroids.

Histopathology in giardiasis: a correlation with diarrhoea.

There is controversy both in regard to the severity of small bowel mucosal damage attributable to giardiasis and to the causal relationship of these changes to the associated diarrhoea. In this series of 17 consecutive patients with giardiasis, small bowel histology and diarrhoea were independently assessed and compared. Disaccharidase assays were performed in 16 of these patients and a repeat biopsy obtained in seven cases. On histological examination the villous architecture varied from normal to sub-total villous atrophy. When these changes were compared with the severity of diarrhoea, a direct correlation was obtained, the more severe symptoms being associated with the more severe villous changes. Repeat biopsy after treatment demonstrated improvement in the histology which correlated with improvement in diarrhoea. Lactase activity was low in all patients with moderate or severe diarrhoea as well as in some patients with mild diarrhoea, two of whom had normal histology. This series demonstrates the occurrence of a spectrum of mucosal changes in giardiasis and supports the concept that these changes mediate the diarrhoea associated with this gut parasite.