Postmortem magnetic resonance imaging as an adjunct to perinatal autopsy for renal-tract abnormalities

The aim of this study was to compare postmortem magnetic resonance imaging (MRI) of the renal system with autopsy in perinatal and fetal deaths. 37 deaths were studied and renal abnormalities were found in five of these cases. Postmortem MRI provided information of diagnostic utility comparable to that obtained by autopsy.

Genetic instability in patients with metachronous colorectal cancers

BACKGROUND

Nearly 7 per cent of patients who undergo resection for colorectal cancer develop metachronous cancers several years later. A molecular marker that could identify patients susceptible to metachronous cancers would be of clinical importance.

METHODS

Twenty-four colorectal cancers from 15 individuals with metachronous colorectal cancer were investigated for microsatellite instability at five loci by single stranded conformational polymorphism analysis. A control group of 14 colorectal cancers from individuals who had only developed one sporadic colorectal cancer each was analysed similarly.

RESULTS

Microsatellite instability was demonstrated in 17 of 24 cancers from individuals with metachronous cancer compared with one of 14 cancers from individuals with a single colorectal cancer.

CONCLUSION

These results suggest that testing for microsatellite instability may be useful in recognizing patients at high risk of developing metachronous colorectal cancers.

Photodynamic therapy of a transplanted pancreatic cancer model using meta-tetrahydroxyphenylchlorin (mTHPC)

Pancreatic cancer is difficult to treat, even for tumours localized to the pancreas. Photodynamic therapy (PDT) is a non-thermal technique for producing localized tissue necrosis with light after prior administration of a photosensitizing drug and it could have a role in the local treatment of these cancers. We studied PDT in a transplanted cancer in the hamster pancreas using the photosensitizer mTHPC (meta-tetrahydroxyphenylchlorin). Fluorescence microscopy showed maximum levels of mTHPC in normal pancreas 2-4 days after sensitization and in tumour at 4-5 days. For PDT, animals were given 0.1 or 0.3 mg kg(-1) mTHPC and the tumour was treated at laparotomy 2 or 4 days later with red light (50 J at 650 nm, continuous or fractionated) delivered via a single fibre touching the tumour surface. The maximum zone of tumour necrosis (seen 3 days after PDT) was 8.7 mm in diameter with continuous irradiation, increasing to 12.4 mm with light fractionation (four equal fractions with 3 min between fractions). The main complication was sealed duodenal perforation, seen in 3 of 16 animals, probably due to inadequate shielding of the duodenum from the light. The duodenal problems seen in hamsters are unlikely to cause trouble in the much thicker human duodenum. PDT tumour necrosis in this animal model has now been shown with a range of photosensitizers, but mTHPC is attractive as it is likely to produce the largest volumes of necrosis around each treatment point with short light exposure times. This technique could have a role in the treatment of localized cancers of the pancreas in patients unsuitable for surgery and can now be considered for preliminary clinical trials.

Non-invasive perinatal necropsy by magnetic resonance imaging

BACKGROUND

AT present necropsy is done in less than 60% of cases of perinatal death in the UK, despite the value of the procedure to the bereaved parents and their doctors. This low rate reflects the difficulty in discussing the examination during the acute distress after the death of a baby, and the personal and religious objections of many parents to necropsy. We compared post-mortem magnetic resonance imaging (MRI) of the fetus with internal perinatal necropsy to assess whether MRI examination is a feasible option for the 40% of cases where consent for necropsy is not given or requested.

METHODS

We examined 20 stillborn, miscarried, or aborted fetuses by MRI and necropsy. Scanning was done in a 1.5 T system, in accordance with our protocol, immediately before necropsy. The MRI and necropsy findings were compared to assess how much diagnostic information was obtained by each technique.

FINDINGS

In eight of the 20 cases the two examinations were in total agreement about the abnormalities present. In eight cases the necropsy provided more detailed information than MRI examination, but in four cases the MRI information was more extensive than that obtained at necropsy. In two of the latter cases, abnormalities of the central nervous system were seen only on MRI. Thus, in 12 (60%) of the 20 cases studied, MRI had equivalent or better diagnostic sensitivity than internal necropsy examination; in 18 (90%) of the 20 cases the two examinations were of similar clinical significance.

INTERPRETATION

MRI of the stillborn or aborted fetus provides non-invasive access to information previously available only from necropsy.

Fine needle aspiration (FNA) cytology of the breast: the influence of unsatisfactory samples on patient management

FNA continues to play an important role in the management of patients with breast lesions. However, the reliability and efficiency of the FNA service depends heavily on the quality of the specimens. We have audited the rate of "inadequate FNAs' at intervals over the last 5 years and related our findings to the clinical expertise of the aspirator. We have also correlated the rate of inadequate FNAs with the percentage of patients who had an FNA preceding a definitive diagnosis of cancer. We report trends in the rate of inadequate samples, and subsequent diagnosis of cancer, over a 5-year period. The percentage of breast FNA samples reported as inadequate was 46.8% in 1988-89, falling to 20% in 1991-92 with the introduction of an FNA clinic, and rising to 30.6% in 1993. The rates of cancer following inadequate FNA were 15.7%, 16.1% and 4.2%, respectively, and the percentage of patients with cancer having a preceding inadequate FNA were 37.5%, 13.2% and 7.1%. Possible explanations for the apparent paradox between increasing numbers of inadequate FNA specimens and a falling breast cancer rate are discussed.

The PAX2 tanscription factor is expressed in cystic and hyperproliferative dysplastic epithelia in human kidney malformations

Human dysplastic kidneys are developmental aberrations which are responsible for many of the very young children with chronic renal failure. They contain poorly differentiated metanephric cells in addition to metaplastic elements. We recently demonstrated that apoptosis was prominent in undifferentiated cells around dysplastic tubules (Winyard, P.J.D., J. Nauta, D.S. Lirenman, P. Hardman, V.R. Sams, R.A. Risdon, and A.S. Woolf. 1996. Kidney Int. 49:135-146), perhaps explaining the tendency of some of these organs to regress. In contrast, apoptosis was rare in dysplastic epithelia which are thought to be ureteric bud malformations. On occasion, these tubules form cysts which distend the abdominal cavity (the multicystic dysplastic kidney) and dysplastic kidneys may rarely become malignant. We now demonstrate that dysplastic tubules maintain a high rate of proliferation postnatally and that PAX2, a potentially oncogenic transcription factor, is expressed in these epithelia. In contrast, both cell proliferation and PAX2 are downregulated during normal maturation of human collecting ducts. We demonstrate that BCL2, a protein which prevents apoptosis in renal mesenchymal to epithelia] conversion, is expressed ectopically in dysplastic kidney epithelia. We propose that dysplastic cyst formation may be understood in terms of aberrant temporal and spatial expression of master genes which are tightly regulated in the normal program of human nephrogenesis.

Deregulation of cell survival in cystic and dysplastic renal development

Various aberrations of cell biology have been reported in polycystic kidney diseases and in cystic renal dysplasias. A common theme in these disorders is failure of maturation of renal cells which superficially resemble embryonic tissue. Apoptosis is a feature of normal murine nephrogenesis, where it has been implicated in morphogenesis, and fulminant apoptosis occurs in the small, cystic kidneys which develop in mice with null mutations of bcl-2. Therefore, we examined the location and extent of apoptosis in pre- and postnatal samples of human polycystic and dysplastic kidney diseases using propidium iodide staining, in situ end-labeling and electron microscopy. In dysplastic kidneys cell death was prominent in undifferentiated cells around dysplastic tubules and was occasionally found in cystic epithelia. The incidence of apoptosis was significantly greater than in normal controls of comparable age both pre- and postnatally. In the polycystic kidneys there was widespread apoptosis in the interstitium around undilated tubules distant from cysts, in undilated tubules between cysts and in cystic epithelia. The level of apoptosis compared to controls was significantly increased postnatally. A similar increase of cell death was also noted in the early and late stages of renal disease in the polycystic cpk/cpk mouse model. We speculate that deregulation of cell survival in these kidneys may reflect incomplete tissue maturation, and may contribute to the progressive destruction of functional kidney tissue in polycystic kidneys and the spontaneous involution reported in cystic dysplastic kidneys.

The effects of gemeprost on the second trimester fetus

OBJECTIVE

To determine whether the use of gemeprost is associated with histological changes in the second trimester fetus.

SETTING

Histopathology department of a university hospital.

DESIGN

Retrospective comparison of histological features in fetuses aborted following maternal administration of gemeprost, with those in fetuses after spontaneous miscarriage.

OUTCOME MEASURES

Degree of tissue fragmentation; other histological abnormalities.

RESULTS

Significantly greater fragmentation of the liver was found in fetuses exposed to gemeprost (P = 0.046). Nonsignificant effects were found for brain (P = 0.082) and heart (P = 0.183), and no effect was seen on the kidney, adrenal and lung. No other significant histological differences were found between the two groups.

CONCLUSIONS

This study is the first to document an effect of gemeprost on the fetus, but confirmation is required in further studies. Other implications are discussed.

The lactase persistence/non-persistence polymorphism is controlled by a cis-acting element

Lactase activity is present at high levels in the small intestine of some human adults and not others. This is due to a genetically determined polymorphism which affects the developmental regulation of the expression of the lactase gene. This polymorphism is of considerable interest in relation to cultural differences in nutrition but despite exhaustive studies, the molecular basis has not yet been found. It has not even been shown whether the sequence differences reside within or adjacent to the lactase gene itself or in a trans-acting factor. We have therefore exploited known DNA 'marker' polymorphisms within the exons of the lactase gene to examine the expression of the individual lactase mRNA transcripts from persistent and non-persistent individuals in order to determine whether the regulation is in cis or trans. Our results show that in certain lactase persistent individuals one allele of the lactase gene is expressed at much lower levels than the other and these individuals tend to have intermediate lactase activities. It is proposed that these people are heterozygous for the lactase persistence and non-persistence alleles and that this means that the nucleotide substitutions responsible for the lactase persistence/non-persistence polymorphism are cis-acting. This narrows down considerably the area of the genome that needs to be searched for the relevant sequence differences.

Studies on the expression of intestinal lactase in different individuals

Sixty one duodenal biopsy specimens were examined for the expression of lactase at the level of enzyme activity, protein, and messenger RNA. Of the 51 samples with normal villous architecture, 39 were lactase persistent, 11 were nonpersistent (adult type hypolactasia), and one was of indeterminate status. All the lactase persistent individuals showed high mRNA and a high level of the lactase protein as detected by sodium dodecyl sulphate polyacrylamide gel electrophoresis. All the 11 non-persistent individuals tested showed a low level of lactase protein. Nine of the 10 samples tested showed low mRNA and one high mRNA. These results suggest that the lactase persistence polymorphism is controlled at the level of the expression of the lactase gene, though there may be some heterogeneity of the lactase non-persistence phenotype.

Albuterol and nedocromil sodium affect airway and leukocyte responses to allergen

We investigated the effects of inhaled nedocromil sodium and albuterol administered prior to allergen challenge in the late asthmatic response (LAR) and circulating cells in a double-blind placebo-controlled study. An additional control day (no allergen) was included to determine diurnal variation. On the control day no change in airway caliber occurred, but a diurnal increase in the numbers of all circulating leukocytes except basophils was seen. Placebo premedication followed by allergen challenge caused both an early asthmatic response (EAR) and a late asthmatic response (LAR). Following allergen challenge after placebo the diurnal increase in eosinophils at 8 h was abolished, and elevated eosinophil and basophil counts were observed at 24 h. Nedocromil sodium attenuated both the EAR and the LAR, and it restored the eosinophil and basophil responses toward normal. Albuterol abolished the EAR and attenuated the LAR and the 24-h increase in circulating basophils. No changes in lymphocyte subpopulations were seen. We conclude that during the LAR there is entrainment of eosinophils within the lung, with a subsequent bone marrow response increasing peripheral populations of eosinophils and basophils. Nedocromil sodium may act by inhibiting the recruitment of inflammatory cells, particularly eosinophils, possibly by affecting the generation of cytokines and the expression of leukocyte-specific adhesion molecules. Albuterol may have similar actions as shown by an effect on basophils.

Evaluation of PGP9.5 in the diagnosis of Hirschsprung's disease

The ability of an acetylcholinesterase-stained frozen section to detect an increase in large cholinergic nerve fibres within the muscularis mucosae and extending into the lamina propria was a significant step forward in the diagnosis of Hirschsprung's disease (HD). However, such frozen section diagnosis is not always possible. The purpose of this study was to assess the ability of PGP9.5 to detect this pattern of mucosal nerve fibre staining immunohistochemically. Sixty-four specimens were included in the study. Twenty-six of these had been diagnosed as HD by conventional means. All cases were stained immunohistochemically with PGP9.5, S100, and anti-neurofilaments (NF). Twenty-four cases of HD were also stained with neurone-specific enolase (NSE). PGP9.5 reliably stained fibres in the mucosal and submucosal plexuses, and ganglion cells, when the latter were present. This positive staining of ganglion cells was more intense than that seen with NSE, and the positive fibre staining was more intense than that seen with NF. Increased lamina propria fibres were detected with PGP9.5 in only 37 per cent of HD cases compared with S100 positive staining in 60 per cent of cases. However, when S100 staining was assessed alone, it gave a higher false-negative rate in diagnosing HD than PGP9.5 used alone. Therefore we would recommend the use of PGP9.5 and S100 together for the immunohistochemical diagnosis of HD in formalin-fixed biopsies.

Ectopic pancreas. A cause of false-positive peritoneal cytology

A patient with a history of ovarian adenocarcinoma underwent further surgery because malignant cells were reported in peritoneal washings on two separate occasions. Subsequent laparotomy revealed an ectopic pancreas on the jejunum. Review of the peritoneal cytologies confirmed that the cells previously thought to be malignant were in fact consistent with cells detached from the ectopic pancreas.

Disseminated porokeratosis in an infant with craniosynostosis

An infant with craniosynostosis and other congenital defects developed a progressive skin rash from the age of 1 month. Histological examination revealed dyskeratosis and a cornoid lamella suggestive of porokeratosis. This patient is remarkable for the early onset and severity of the skin disease.

Detection of occult nodal metastases in patients with colorectal carcinoma

Immunohistochemical study may be used for detecting micrometastases by their expression of tumor-associated antigens. In 48 specimens of colorectal cancer from 47 patients, 49 of 249 lymph nodes (median, five per patient; range, 2-11) examined by light microscopic study contained tumor deposits. Sections of all lymph nodes were also examined by immunohistochemical study for carcinoembryonic antigen (CEA) and epithelial membrane antigen (EMA) expression using the indirect immunoperoxidase staining method. All 49 lymph node metastases (100%) from 20 patients stained positively for CEA and 45 (92%) expressed EMA. Of the 200 lymph nodes without metastases on light microscopic examination, anti-CEA revealed a single micrometastasis in a patient staged as Dukes' B. No additional metastases were detected with anti-EMA. In this series of patients immunohistochemical study has, therefore, influenced the histologic staging in only one patient (2%) and thus does not offer a significant benefit over conventional histologic staging.

Comparative study of carcinoembryonic antigen and epithelial membrane antigen expression in normal colon, adenomas and adenocarcinomas of the colon and rectum

The heterogeneous nature of tumour antigen expression may require selection of monoclonal antibodies on an individual patient or tumour basis to allow adequate tumour localisation. Carcinoembryonic antigen (CEA) and epithelial membrane antigen (EMA) expression has not previously been compared in colorectal cancer patients. Sections of cancer (n = 52), adjacent normal colon (n = 45), synchronous adenomas (n = 11) and nodal metastases (n = 49) were examined by indirect immunoperoxidase staining in 51 consecutive patients with colorectal cancer using monoclonal antibodies to CEA and EMA. The percentage of cells with positive staining in the primary tumours was graded 1: less than 25%, 2: 25-49%, 3: 50-75%, 4 greater than 75%. All primary colorectal cancers expressed CEA and 43 of 52 expressed EMA (83%). Grading showed CEA greater than EMA in 39, equal in 11 and less in two. Well differentiated cancers were more frequently graded three or four for CEA staining (23 of 27) than moderately differentiated cancers (11 of 22) (p less than 0.01). Equivalent figures for EMA were four of 27 and three of 22 (not significant) (NS) although the majority (86%) were graded 1 and 2. Grade 1 CEA expression was found in six of 15 proximal and only two of 37 distal lesions (p less than 0.01, chi 2 test) while for EMA equivalent figures were three of 15 and six of 37 (NS). Nodal deposits all expressed CEA and 45 of 49 expressed EMA (92%); 29 of 45 normal colon sections showed CEA expression (64%) as did all adenomas. EMA was not expressed by normal colon or adenomas. These results suggest that EMA expression is more specific but less sensitive than CEA for colonic cancer and is independent of tumour differentiation and site. Thus selecting monoclonal antibodies to CEA or EMA based on tumour biopsies may allow improved tumour localisation for imaging or therapy in patents with colorectal cancer.