Nuclear thymidylate synthase expression, p53 expression and 5FU response in colorectal carcinoma

Thymidylate synthase (TS) is a key enzyme in DNA synthesis and is inhibited by metabolites of the chemotherapeutic agent 5-fluorouracil (5FU). Nuclear expression of TS in human tissue in vivo has not been characterised and its clinicopathological correlates in malignancy are unknown. 52 cases of primary colorectal carcinoma (CRC) and 24 cases of matched metastatic carcinoma were studied immunohistochemically using the monoclonal antibody TS106. The degree of nuclear TS immunostaining correlated closely with levels of TS mRNA expression amongst 10 CRCs studied. Strong nuclear immunostaining was seen in normal basal crypt colonocytes and germinal centre cells, and in a varying proportion of adenocarcinoma cells. Amongst the primary carcinomas, higher TS nuclear expression was associated with prominent extracellular mucin production and right-sided location. Higher TS nuclear expression also showed a significant association with poorer response to protracted venous infusional 5FU therapy. There was no clear association between TS nuclear expression and Ki67 or p53 expression assessed immunohistochemically. There was a strong positive correlation between TS nuclear expression in primary and metastatic CRC but the latter generally showed higher expression than matched primary tumour tissue. These findings confirm the nuclear expression of TS protein in human cells in vivo and provide new insight into how such expression may relate to the behaviour of CRCs.

Colorectal neoplasia in ulcerative colitis-recent advances

It is recognized that ulcerative colitis (UC) predisposes to the development of colorectal adenocarcinoma (CRC), and the molecular pathway for this process differs from that for sporadic CRCs. However, several important details regarding the risk factors for and the molecular changes underlying UC-related colorectal carcinogenesis have only come to light lately. First, recent data suggest environmental factors related to long-standing inflammation contribute more to this increased cancer risk than an inherited susceptibility. Second, molecular changes that may represent the first steps in the development of neoplasia are being increasingly identified in non-dysplastic, colitic mucosa. Third, there is now good evidence suggesting that UC-related CRC may develop along more than one molecular pathway. These emerging data will hopefully contribute to attempts to prevent the development of UC-related CRC, e.g. through refining surveillance programmes. Details of the molecular heterogeneity of UC-related dysplasia and CRC may also help develop reliable tools for diagnosing the former and for predicting the behaviour of the latter. Finally, there is increasing awareness of non-epithelial colorectal malignancies which are associated with UC and may potentially increase in incidence with changes in the medical management of this inflammatory disease.

Intra-abdominal spindle cell lesions: a review and practical aids to diagnosis

Intra-abdominal spindle cell lesions are uncommon and often present a diagnostic challenge. An important group of such lesions are the gastrointestinal stromal tumours. Other intra-abdominal spindle cell lesions include fibromatosis, various sarcomas-in particular, leiomyosarcoma, liposarcoma, and malignant peripheral nerve sheath tumour-and, in women, endometrial stromal sarcoma. Less common lesions are inflammatory myofibroblastic tumours, the mesenteric spindle cell reactive lesions, retroperitoneal fibrosis, and solitary fibrous tumour. A variety of intra-abdominal tumours of nonmesenchymal origin may have a spindle cell/sarcomatoid morphology; these include sarcomatoid carcinoma, malignant melanoma and, in women, sarcomatoid granulosa cell tumour. Finally, metastatic sarcomas from pelvic or extra-abdominal organs need also be considered. A set of practical aids to the diagnosis of intra-abdominal spindle cell lesions is presented to assist pathologists dealing with such lesions, particularly with regards to the consideration of differential diagnoses.

Immunohistochemical assessment of Ki67 and p53 expression assists the diagnosis and grading of ulcerative colitis-related dysplasia

AIMS

To assess whether Ki67 and p53 immunostaining may assist the diagnosis and grading of ulcerative colitis-related dysplasia.

METHODS AND RESULTS

Location of Ki67 staining and location and intensity of p53 staining were assessed in ulcerative colitis (UC) cases showing the features of high-grade dysplasia (HGD, n = 14), low-grade dysplasia (LGD, n = 22), 'indefinite for dysplasia' (n = 12), or regenerative atypia (RA, n = 22). Good intra- and inter-observer reproducibilities were demonstrated in the performance of these assessments. All the dysplasia cases showed extension of Ki67 staining above the basal third of the crypt. Moderate intensity p53 staining was seen in 10/22 RA cases, but strong intensity p53 staining was seen only in cases of dysplasia. All the cases of HGD showed extension of Ki67 and p53 staining above the basal two thirds of the crypt.

CONCLUSIONS

Restriction of Ki67 staining to the basal third of the crypt appears to exclude a diagnosis of dysplasia whereas strong intensity p53 staining suggests a diagnosis of dysplasia. Restriction of Ki67 or p53 staining to the basal two-thirds of the crypt appears to exclude a diagnosis of HGD.

Polymorphisms of the gene for microsomal epoxide hydrolase and susceptibility to alcoholic liver disease and hepatocellular carcinoma in a Caucasian population

The gene encoding the xenobiotic-metabolising microsomal enzyme, epoxide hydrolase (mEPHX), shows two common mutations, i.e. at exons 3 and 4. It is unknown how these genetic polymorphisms relate to risk of developing alcoholic liver disease (ALD) and/or hepatocellular carcinoma (HCC) in a Caucasian population. DNA samples extracted from the blood of 61 ALD patients and 203 healthy controls, and from archival liver tissue of 46 cases of HCC, were subjected to polymerase chain reaction amplification followed by digestion with EcoR V or Rsa I to demonstrate polymorphisms of exon 3 or 4, respectively. The distributions of the genotypes of exon 3 in the ALD and HCC patients, and exon 4 in the HCC patients did not differ significantly from those of the control group. However, compared with the control group, the ALD group contained a significantly greater number of individuals homozygous or heterozygous for the exon 4 mutation. This suggested association between possession of the exon 4 mutant mEPHX allele and increased risk of developing ALD may relate to known interactions between mEPHX and alcohol-metabolising enzyme systems, or to linkage disequilibrium between the mutation and other genetic risk factors for ALD.

Genetic polymorphisms of cytochrome p4502E1 and susceptibility to alcoholic liver disease and hepatocellular carcinoma in a white population: a study and literature review, including meta-analysis

AIMS

To investigate the associations between the Rsa I, Dra I, and Taq I genetic polymorphisms of cytochrome p4502E1 and susceptibility to alcoholic liver disease or to hepatocellular carcinoma.

METHODS

DNA samples isolated from 61 patients with alcoholic liver disease, 46 patients with hepatocellular carcinoma, and 375 healthy controls were subjected to polymerase chain reaction amplification followed by digestion with the endonucleases Rsa I, Dra I, or Taq I. Meta-analysis was performed using data from previous studies of Rsa I polymorphism and the risk of alcoholic liver disease.

RESULTS

No association was found between any of the three polymorphisms and susceptibility to hepatocellular carcinoma. The distributions of Rsa I and Dra I alleles among the patients with alcoholic liver disease were not significantly different from those among the control group. Meta-analysis of this data and previous data concerning Rsa I polymorphism and alcoholic liver disease risk failed to demonstrate any significant association between the two. However, the alcoholic liver disease group in this study showed a significantly lower frequency of the less common Taq I allele compared with the healthy control group (odds ratio, 0.33; 95% confidence interval, 0.12 to 0.78).

CONCLUSIONS

Possession of the less common Taq I cytochrome p4502E1 allele is associated with reduced susceptibility to alcoholic liver disease. There is no existing evidence that the Taq I polymorphism is directly associated with altered alcohol metabolism, but it might be in linkage disequilibrium with as yet unidentified protective factors.

Imprint cytology of parathyroid tissue in relation to other tissues of the neck and mediastinum

OBJECTIVE

To retest the hypothesis that imprint cytology may be used to reliably diagnose parathyroid tissue and, if so, to ascertain whether accuracy in this technique may be easily attained.

STUDY DESIGN

Imprint preparations from 15 parathyroid, 10 thyroid, 8 lymphoreticular and 2 adipose tissue specimens were assessed blindly by two pathologists, one of whom (pathologist B) had only limited experience with endocrine tissue imprint cytology.

RESULTS

Both assessors consistently distinguished parathyroid and thyroid preparations from lymphoreticular and adipose tissue preparations. While there was occasional difficulty in distinguishing between parathyroid and thyroid preparations, this was usually attributable to the scanty nature of the preparations. No single cytologic feature allowed a distinction between parathyroid and thyroid tissue. However, by considering several relatively diagnostic features collectively, pathologist B showed an increase in specificity and sensitivity rates for distinguishing parathyroid from thyroid imprints from 82% to 100% and 57% to 83%, respectively.

CONCLUSION

The high accuracy rates and rapid [table: see text] learning curve shown by imprint cytology in distinguishing between different neck or mediastinal tissue types, together with its time- and cost-cutting potential, support a role for the technique in the intraoperative diagnosis of parathyroid tissue.

Measurement of vascularity as a diagnostic and prognostic tool for well differentiated thyroid tumours: comparison of different methods of assessing vascularity

AIMS

To determine whether the measurement of vascularity can be used to differentiate follicular adenomas from follicular carcinomas or to reflect the prognosis of follicular carcinomas and papillary carcinomas of the thyroid gland, and to compare four methods of assessing vascularity.

METHODS

Tissue sections from 26 papillary carcinomas, 15 follicular adenomas, and 15 follicular carcinomas were stained with an antibody to CD34. A computerised image analysis system was used to calculate, for each tumour, mean endothelial areas and the mean endothelium to tumour epithelial nucleus area ratio from 10 systematically selected fields across one dimension of the tumour ("systematic field" analysis) or from the three most vascularised fields of the tumour ("hot spot" analysis). A European Organisation for Research on Treatment of Cancer (EORTC) prognostic index was calculated for each papillary carcinoma and follicular carcinoma.

RESULTS

Significant differences in vascularity between the three tumour groups could only be shown by comparing mean endothelial area values measured from hot spots. While the hot spot median mean endothelial area of follicular carcinomas was significantly greater than that of follicular adenomas, there was a large overlap between the two groups. For follicular carcinomas, higher hot spot mean endothelial area values were related to worse prognosis as indicated by the EORTC prognostic indices. No association between vascularity and prognosis was found for the papillary carcinomas, regardless of the method of assessing vascularity.

CONCLUSIONS

Measuring endothelial area from hot spots using a computerised image analysis system is a sensitive method of assessing the vascularity of thyroid tumours. While vascularity measurement cannot be recommended as a practical tool for differentiating between malignant and benign follicular tumours, the suggestion that vascularity may reflect prognosis for follicular carcinomas deserves further study.

Primary yolk sac tumour of the liver in adulthood

Primary yolk sac tumour of the liver is exceedingly rare. A 28 year old woman presented with a cystic liver mass and a markedly raised serum alpha-fetoprotein concentration. She underwent a partial hepatectomy for a suspected hepatocellular carcinoma but histological examination of the tumour revealed the classical morphological and immunohistochemical features of a yolk sac tumour. There was no evidence of an extrahepatic primary source. Review of this case, together with the six previously reported adult cases of primary yolk sac tumours of the liver, revealed several features of the tumour that may aid differentiation from hepatocellular carcinoma, with potential therapeutic implications.

No correlation between phaeochromocytoma catecholamine secretion and granule ultrastructure

BACKGROUND

It is uncertain whether biochemical markers of catecholamine secretion in patients with phaeochromocytoma correlate with tumour ultrastructure granule morphology.

METHODS

Fifteen patients with an adrenal phaeochromocytoma (n=13) or paraganglioma (n=2) (three men, 12 women; age 17-79 years) were studied. Catecholamine secretion was estimated by measuring urinary levels of free noradrenaline, adrenaline and dopamine. The number and type of secretory granules were evaluated by two independent observers on electron micrographs (area analysed approximately 70 microm2). Large round or elongated medium-density granules were adrenaline-type granules, whereas electron-dense granules lying in a vacuole were of noradrenaline type.

RESULTS

No correlation was found between noradrenaline output and the number or percentage of noradrenaline-type granules, although tumours with normal noradrenaline output had only a minority of this type of granule (less than 25 per cent). Adrenaline-type granules were predominant (77 per cent of 163 granules) in a tumour secreting only adrenaline, but the proportion of adrenaline-type granules in six tumours with normal adrenaline output varied significantly (range 7-89 per cent). It was not possible to evaluate the granule type associated with dopamine secretion because one tumour secreting 14900 nmol dopamine and 1570 nmol adrenaline daily had a predominance of noradrenaline-type granules (63 per cent of 132 granules) and two dopamine-secreting tumours (5500 and 4250 nmol per day respectively) had 93 and 13 per cent noradrenaline-type granules.

CONCLUSION

The lack of correlation between hormone output and granularity suggests that other factors determine secretory patterns in these tumours.

An analysis of discharge drug prescribing amongst elderly patients with renal impairment

Renal impairment is common amongst elderly patients and increases the risk of drug toxicity. Analysis of the discharge summaries of patients discharged from the geratology wards of an Oxfordshire hospital, showed that renal impairment was not referred to in 42% of patients with calculated creatinine clearances of 10-20 ml/min. A fifth of these patients, and 67% of patients with calculated creatinine clearances < 10 ml/min, had discharge drug prescriptions that contradicted the British National Formulary guidelines for prescribing in the presence of renal impairment. There should be increased awareness that, in elderly patients, normal serum creatinine concentrations do not exclude renal impairment and that several commonly prescribed drugs require dose adjustments or should be avoided in the presence of renal insufficiency.

Unacceptably high site variability in postmortem blood alcohol analysis

Blood alcohol concentration is a frequently requested test in forensic pathology. The variability of this value was studied by measuring the blood alcohol concentration from six sites in nine subjects at necropsy in whom alcohol was the implicated cause of death. There were small consistent differences in the blood alcohol concentrations between the sites in the nine subjects (p < 0.04). Calculation of the mean blood:vitreous humour alcohol concentration ratio (B:V ratio) showed that vitreous humour alcohol concentration most closely reflected the concentration at the femoral vein (B:V ratio = 0.94, r = 0.98), which is considered the optimal site for blood alcohol measurement. The correlation of left heart blood with femoral blood was lower compared with the other sites. There is a potential for an unacceptably large variation in the postmortem measurement of blood alcohol within each subject.

Risk factors for developing neonatal septicaemia at a Malaysian hospital

A case-control study of antecedents of neonatal septicaemia was performed using 50 cases of neonatal septicaemia and 73 comparison infants from a Malaysian hospital nursery. Multivariate analysis indicated the following independent risk factors: maternal primiparity, pre-eclampsia, prolonged rupture of membranes, twin pregnancy, prematurity, assisted ventilation, umbilical catheterization, and formula feeding. Although the spectrum of causative organisms varied between our study and past studies from Western countries, the risk factors for developing neonatal septicaemia were strikingly similar. Therefore, preventative guidelines based on risk factors described in Western countries, should help reduce the incidence of neonatal septicaemia at this Malaysian hospital.

Acromegaly or chronic renal failure: a diagnostic dilemma

Uraemic patients may have markedly elevated serum GH concentrations yet, for hitherto unknown reasons, they do not develop acromegaly. We discuss the diagnostic dilemma presented by a 33-year-old Caucasian male with chronic renal failure (creatinine clearance 10 ml/min) secondary to polycystic kidney disease, elevated GH concentrations (fasting concentration of 22.6 rising to 77.9 mU/l 30 minutes after a 75-g oral glucose load) as well as acromegalic features. Review of the patient's relatives and the findings of a normal serum IGF-I concentration and a normal pituitary fossa on magnetic resonance imaging, suggest that the patient's acromegalic appearance is a familial trait and his abnormal GH dynamics a result of his renal failure rather than acromegaly. The patient's normal GH bioactivity and reduced GH binding protein concentration supports the current belief that chronic renal failure leads to an increase in peripheral tissue resistance to GH due to decreased GH receptor numbers. These changes, together with reduced IGF-I bioactivity, may explain why patients with chronic renal failure do not develop acromegaly in the presence of abnormally elevated levels of GH.

Early postoperative plasma calcium concentration as a predictor of the need for calcium supplement after parathyroidectomy

This study evaluated early postoperative serum calcium concentration as a predictor of hypocalcaemic symptoms and the need for calcium supplements. A total of 64 consecutive patients undergoing curative parathyroidectomy for primary hyperparathyroidism were studied. Twenty patients (31 per cent) developed hypocalcaemic symptoms requiring calcium supplements. Plasma calcium levels in the preoperative and early postoperative periods were similar in patients who required calcium supplements and those in whom they were not necessary. There was no significant difference in the percentage decrease in early calcium levels after operation between the two groups. In those undergoing reoperative surgery and subtotal parathyroidectomy the percentage decline was significantly higher in patients who required calcium supplements (12.8 versus 5.6 per cent, P < 0.005). A fall of 10 per cent or more was consistently followed by hypocalcaemic symptoms. Calcium determination in the early postoperative period is of little value in predicting the onset of hypocalcaemic symptoms.

Acute respiratory distress secondary to Morgagni diaphragmatic herniation in an adult

Diaphragmatic hernias of the Morgagni type are generally thought to be asymptomatic in adults. This traditional assumption led to a delay in diagnosing a Morgagni hernia as the cause of acute respiratory distress in a chronic schizophrenic man. While Morgagni hernias are usually considered to be long-standing, we present radiological evidence of an acutely expanding hernia. The patient's symptoms were relieved by surgical repair of the hernia. We advise caution before dismissing Morgagni hernias in adults as being long-standing and clinically insignificant.

Randomly amplified polymorphic DNA typing: a useful tool for rapid epidemiological typing of Klebsiella pneumoniae

Discriminatory typing methods are invaluable in the investigation of outbreaks of infectious diseases. Single primers were used to generate randomly amplified polymorphic DNA (RAPD) profiles from Klebsiella pneumoniae isolates of various serotype and K. pneumoniae isolates from cases of sepsis at a Malaysian hospital and two English hospitals. RAPD profiles of acceptable reproducibility, a maximum of three minor band variations, were produced using a rapid DNA extraction method. RAPD typing of K. pneumoniae was shown to be as discriminatory as restriction fragment length polymorphism analysis using pulsed field gel electrophoresis yet quicker and less costly. The findings suggest that RAPD typing may be a useful tool for the epidemiological typing of K. pneumoniae.