Role of mast cells in experimental tumour angiogenesis

Although the morphological features of angiogenesis are well documented and many promoting factors are known, the pharmacological mechanisms for the development of new vessels are not understood. Compounds found in platelets and/or mast cells--adenosine diphosphate, 5-hydroxytryptamine, histamine and heparin--caused endothelial cell growth stimulation in vitro: tumour angiogenesis factor did not. These same vasoactive compounds, as well as tumour angiogenesis factor, induced neovascularization on the chick chorioallantoic membrane. The increased vascularity produced by tumour angiogenesis factor was associated with considerable numbers of mast cells. These findings, together with an appreciation of the biochemical armoury of the mast cell and how its products could relate to the morphological steps of angiogenesis, and a realization that known anti-angiogenesis factors could all act through inhibition of mast cell products, strongly implicate the mast cell in the inductive mechanisms of neovascularization.

Observer variability in the Goseki grouping of gastric adenocarcinoma in resection and biopsy specimens

AIMS

The Goseki grouping of gastric adenocarcinoma has been suggested as a possible prognostic factor. In those centres where it is used, it may be valuable to assess the Goseki grouping of a tumour on the initial diagnostic biopsy as well as on the resection specimen since it may in theory influence management. We examined the robustness of Goseki grouping of gastric adenocarcinoma in representative sections from resection and biopsy specimens in order to assess the consistency of agreement among a group of pathologists.

METHODS

A single representative block from 100 gastric resection specimens was studied using a haematoxylin and eosin and mucin (alcian blue/periodic acid-Schiff) stain. These were circulated in batches to members of a group of 12 pathologists who each completed a simple proforma confirming the presence of carcinoma and assigning a Goseki group. In a second circulation the diagnostic biopsy specimen taken prior to resection was examined in the same way. This allowed comparison of the Goseki group of the biopsy and resection specimens.

RESULTS

In both studies kappa statistics showed good agreement on tubular differentiation of the carcinoma, but only moderate agreement for the intracellular mucin production, resulting in moderate agreement for the final Goseki group. Correlation between the Goseki group assigned on the biopsy and resected specimens was seen in 62% of the cases. However, the reproducibility was low (kappa 0.375).

CONCLUSIONS

The Goseki grouping of resected gastric adenocarcinoma is reproducible and can be used in prognostication. Goseki grouping of biopsy specimens is of limited value in predicting the Goseki group assigned to the resected carcinoma.

The Scottish doctor--learning outcomes for the medical undergraduate in Scotland: a foundation for competent and reflective practitioners

This paper describes a set of learning outcomes that clearly define the abilities of medical graduates from any of the five Scottish medical schools. The outcomes are divided into 12 domains that fit into one of three essential elements for the competent and reflective medical practitioner.

Consistency of histopathological reporting of laryngeal dysplasia. The Scottish Pathology Consistency Group

AIMS

Clinical management of premalignant and malignant lesions of the larynx is dependent on histopathological evaluation. The Scottish Pathology Consistency Group assessed interobserver variation in the evaluation of laryngeal dysplasia.

METHODS AND RESULTS

One hundred laryngeal biopsies ranging from normal to invasive carcinoma were assessed. The overall Kappa result of 0.32 was disappointing. However, agreement on those categories which dictate significantly different management was more favourable. The Kappa figure for mild dysplasia versus severe dysplasia/CIS was 0.7, the Kappa figure for mild dysplasia versus severe dysplasia/CIS and invasive carcinoma was 0.77. The Kappa figure for mild and moderate dysplasia versus severe dysplasia/ CIS and invasive carcinoma was 0.57. An attempt to use a two grade system gave a Kappa figure of 0.52.

CONCLUSIONS

Our group had a satisfactory agreement on the distinction of mild from severe dysplasia and on microinvasive carcinoma without any discussion as to histopathological criteria to be used. Clinical management--review endoscopy, repeat cord stripping, radiotherapy and laryngectomy--is in general dependent on histological assessment. Thus the agreement on categories which underpin clinical management is reassuring. However, assessment of moderate dysplasia remains problematic. An attempt to utilize a two grade system--low grade from high grade dysplasia/CIS--may have merit. The implications of the terminology used must be agreed among pathologists and clinicians working closely within clinicopathological cancer groups.

Development and integration of CAL: a case study in medicine

CONTEXT

The Faculty of Medicine and Medical Sciences at the University of Aberdeen viewed the use of Computer Assisted Leaning (CAL) and other IT based learning resources as a possible way of coping with an increase in student numbers whilst maintaining or increasing the quality of medical teaching.

OBJECTIVES

Our primary objective was to develop and integrate Computer Assisted Learning (CAL) applications into the undergraduate medical curriculum.

SUBJECTS/MATERIALS

A wide spectrum of CAL applications were developed dealing with many topics in the curriculum.

METHODS

We formulated a structured approach to CAL development by establishing a team of professionals (forming a CAL Unit), using existing expertise and by implementing a process to ensure that the CAL had a maximum impact upon the curriculum. The CAL included multimedia tutorials, learning guides, computer aided assessment (CAA) and Model Patients.

RESULTS

There are now over 150 IT based learning resources in our curriculum and course evaluation has showed that these have been well received by students.

CONCLUSIONS

We conclude that with the wise use of the many skills and facilities usually available within an institution and by promoting collaborative projects with others, the production of high quality CAL is possible within most institutions.

The expression of beta 1 integrins in human coronary artery

The beta 1 integrin adhesion receptors mediate the binding of cells to extracellular matrices, facilitating their growth, migration, and capacity to deposit matrix proteins: important factors in arterial restenosis and atherosclerosis. The expression of integrins in human coronary artery is, however, unexplored. The aim of the current study was, therefore, to define the expression of beta 1 integrins by cultured human coronary artery vascular smooth muscle cells (hCAVSMC) and in normal human coronary artery; confirming whether or not this differs from the repertoire found in other species and human vessels. The expression of beta 1 integrins by hCAVSMC was assessed by immuno-precipitation and the alkaline phosphatase anti-alkaline phosphatase (APAAP) immunochemical technique. In addition, mRNA expression was defined by reverse transcription polymerase chain reaction (RT-PCR). Normal adult human coronary arteries (n = 4) were also stained by the APAAP method. In vitro hCAVSMC express alpha 2 beta 1 (a collagen and occasional laminin receptor) and alpha 5 beta 1 (a fibronectin receptor) with lesser expression of alpha 3 beta 1 (a multifunctional receptor). They do, however, possess mRNA for several other integrins. Cells within the media of human coronary artery wall express alpha 3 beta 1 and alpha 5 beta 1 but not alpha 2 beta 1: instead the alternative collagen/laminin receptor, alpha 1 beta 1, is expressed in vivo. This pattern of expression differs subtly from that described in rats through it closely parallels that found in other human arteries.

Scleroderma, D-penicillamine treatment, and progressive renal failure associated with positive antimyeloperoxidase antineutrophil cytoplasmic antibodies

Progressive renal failure in patients with scleroderma is a sinister development that is usually attributed to impaired renal blood flow. In some exceptional cases, the underlying pathology is a crescentic glomerulonephritis, which has been associated with positive antineutrophil cytoplasmic antibodies, and in particular antimyeloperoxidase antibodies. The prognosis in such cases has been very poor. We report such a patient whose renal function has improved and stabilized on immunosuppressive therapy.

Upregulation and co-localization of connexin43 and cellular adhesion molecules in inflammatory renal disease

Connexin43 (Cx43) is a major component of gap junctions. These are widely distributed in the human kidney and are thought to be involved in the inflammatory response and in the regulation of cell growth. Cellular adhesion molecules (CAMs) are also thought to be important in these processes, where they possibly facilitate gap junction formation. The aims of the current study were to define for the first time the expression of Cx43 in inflammatory glomerulonephritis and to compare the localization of this connexin with that of the intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin. Human renal biopsies and control sections of normal human kidney were stained using the alkaline phosphatase/anti-alkaline phosphatase immunohistochemical technique, demonstrating that Cx43 was strongly expressed on inflammatory cells, on damaged tubular cells, and on interstitial cells. This pattern of expression was paralleled closely by that of ICAM-1 and, to a lesser extent, by that of VCAM-1. Cx43 is therefore primarily implicated in tubulointerstitial inflammation.

Importance of the tubulointerstitium in human glomerulonephritis. II. Distribution of integrin chains beta 1, alpha 1 to 6 and alpha V

Accumulation of extracellular matrix is important in the progression of glomerulonephritis. Since adherent cell types utilize integrins to bind and organize extracellular matrix proteins, we have assessed expression of the beta 1 integrins in sequential sections from 85 human renal biopsies and 4 normal kidneys by immunohistochemical staining. Our results demonstrate strong correlations between expression of the alpha 5 chain within the interstitium, the alpha V chain on proximal and distal tubular epithelium and the presence of chronic histological damage. Moreover, staining for interstitial alpha 5 and proximal and distal tubular alpha V were also strongly associated with expression of certain adhesion molecules (ICAM-1, VCAM-1, E-selectin and L-selectin) and the presence of macrophages within the interstitium, which have been linked, in an earlier study, with the degree of chronic histological damage and disease progression. However, in contrast to our earlier study of adhesion molecules, there were also associations between expression of integrin chains within the glomerulus and tubulointerstitium. For example, there were strong positive associations between staining for alpha 5 on glomerular endothelium and its expression on extraglomerular vascular endothelium and between both mesangial alpha 1 and podocyte alpha 3 and tubular staining for the common beta 1 subunit. While the functional significance of these associations is obscure, they suggest some kind of communication between cells in different sites in the kidney. There were also positive associations between staining for different integrins within the glomerulus, notably mesangial cell staining for alpha 2, glomerular endothelial cells staining for alpha 5 and glomerular epithelial cell alpha 3. These results suggest that there is a coordinated upregulation of integrin expression both within the tubulointerstitium and the glomerulus and that at least some of these integrins (interstitial alpha 5 and distal tubular alpha V) are associated with the expression of other adhesion molecules, macrophage infiltration and the presence of markers of disease progression (interstitial fibrosis and tubular atrophy).

Apoptosis in atypical fibroxanthoma and pleomorphic malignant fibrous histiocytoma

Explanations for the disparate behavior of atypical fibroxanthoma (AFX) as compared with pleomorphic malignant fibrous histiocytoma (MFH) have included the proposition that the former is a pseudosarcoma. Nonetheless, these tumors are now widely regarded as the same process, but with AFX behaving benignly by virtue of its superficial location. However, a neoplasm's metastastatic potential has been proposed to be related to apoptosis. Therefore, the aim of the present study was to examine apoptotic counts, in conjunction with two important regulators of apoptosis: p53 and bcl-2, to determine if a distinction exists that may account for the different outcomes of these lesions. There was no significant statistical difference between eight AFX and nine pleomorphic MFH in terms of apoptotic behavior, proliferative indexes, p53 protein expression, or presence of bcl-2 product. Therefore, our results further support the contention that AFX should be regarded as a form of pleomorphic MFH, which demonstrates low malignant potential by virtue of its location in readily accessible sites.

Observer variability in the histopathological reporting of needle biopsy specimens of the prostate

The Scottish Pathology Consistency Group has in previous studies examined the consistency of histopathological reporting of biopsies from the cervix, bladder, bronchus, and rectum. In the current study, consisting of 100 needle biopsy specimens of the prostate, a single hematoxylin-eosin (H&E) slide from each case was circulated in batches of 10 to the 12 pathologists, who filled in a simple proforma. This had two sections: a diagnostic category (benign; suspicious or malignant) along with a standard Gleason score for those regarded as malignant. The majority diagnosis of the 100 cases was benign, 53; suspicious, 1; and malignant, 46. The Kappa value for benign cases versus others was 0.86 and for malignant cases versus others was 0.91. Analysis of the data on Gleason scores showed a value of 0.54 when cases were divided into two categories (2 to 6 v 7 to 10) and 0.41 when three categories were used (2 to 4; 5 to 6; 7 to 10). Although not initially part of the design of the study, the majority diagnosis was compared with the original reported diagnosis. In a small subset, examination of further levels, basal cell antibody staining, along with further clinical information, was obtained. With this added information, it appears that there were probably 52 benign and 48 malignant cases. Of the 48 malignant cases, the group majority diagnosis was malignant, 46; suspicious, 1; and benign, 1. The original reported diagnosis was 56 benign, 1 suspicious, and 43 malignant. The group therefore appeared to perform better than the original reporting pathologists. When compared with the results of our previous studies, this study has shown that the diagnosis of carcinoma of the prostate on a needle biopsy is robust.

Expression of beta 1 integrins in IgA nephropathy

AIM

To compare the expression of beta 1 integrins in renal biopsies from patients with IgA nephropathy with that found in normal human kidney.

METHODS

Thirty renal biopsies from patients with IgA disease plus six control specimens were stained with monoclonal antibodies directed against the alpha 1, alpha 2, alpha 3, alpha 4, alpha 5, alpha 6, alpha v, and beta 1 integrin chains using the alkaline phosphatase anti-alkaline phosphatase (APAAP) technique. The intensity of integrin expression was graded semiquantitatively by a pathologist unaware of the antibody used.

RESULTS

Glomerular crescents stained strongly for alpha 3, alpha v, and beta 1, but integrin expression was greatly reduced or absent in fibrotic glomeruli. There were no alterations in the intensity of mesangial cell staining for any of the integrins tested. There was accentuated staining for the alpha 2, alpha 5, alpha v, and beta 1 chains in areas of interstitial scarring plus alpha 2, alpha 3, alpha v, and beta 1 on damaged tubules. Inflammatory cells expressed alpha 4, alpha 5, and beta 1.

CONCLUSIONS

In IgA nephropathy the interstitium is the main site of altered beta 1 integrin expression. Glomerular crescents also express several beta 1 integrins, but we found no differences in the intensity of integrin expression on mesangial cells. Altered beta 1 integrin expression may play a role in tubulointerstitial scarring in IgA disease. Thus modulation of integrin expression might attenuate this process.

The expression of connexin 43 in human kidney and cultured renal cells

Gap junctions enable intercellular communication and play an important role in a variety of vital cellular functions including differentiation and the control of growth. These junctions are formed by a hexameric of proteins known as connexins. We investigated the distribution of the connexin 43 (Cx43) gap junction protein in renal cells and human kidney using the alkaline phosphatase anti-alkaline phosphatase immunohistochemical technique with a monoclonal antibody directed against the cytoplasmic domain of this antigen. Strong staining was demonstrated on the vascular endothelium, the smooth muscle of larger vessels and on glomerular epithelial cells. In addition, Cx43 was expressed on proximal tubular cells, glomerular endothelial cells and occasional cells infiltrating the interstitium. In areas of tubular atrophy there was increased staining for Cx43. Using reverse transcription-polymerase chain reaction we have also demonstrated that cultured human and rat mesangial cells and human proximal tubular cells express Cx43 messenger RNA. In summary, we have described for the first time the distribution of Cx43 in human kidney and cultured renal cells.

Endoglin, a transforming growth factor-beta-binding protein, is upregulated in chronic progressive renal disease

Endoglin is a non-signalling receptor for TGF-beta. In view of the importance of transforming growth factor-beta (TGF-beta) in the pathogenesis of renal disease, we have determined the distribution of TGF-beta in human glomerulonephritis. Endoglin was present within the glomerular mesangium and interstitium in normal kidneys. In diseased biopsies, there was a weak but significant correlation between staining for endoglin in the interstitium and the extent of chronic histological damage (r = 0.3343, p = 0.003). This was supported by division of biopsies into those showing mild damage and those with moderate to severe damage, where the latter group had significantly increased interstitial staining for endoglin (p = 0.0035). However, there was no correlation between mesangial staining for endoglin and specific types of glomerular pathology, such as IgA nephropathy, suggesting that the interstitial expression of endoglin is associated with increased renal damage independent of the specific type of glomerular lesion which initiates the process. There was also a positive correlation between mesangial cell staining for endoglin and interstitial endoglin expression (r = 0.3104, p = 0.003), although the former was not independently associated with chronic histological damage. These data suggest that the response of interstitial fibroblasts and mesangial cells may be linked in glomerulonephritis. Both could contribute to renal scarring by increased binding of TGF-beta which would be independent of the type of initial glomerular damage.

CD44 in glomerulonephritis: expression in human renal biopsies, the Thy 1.1 model, and by cultured mesangial cells

CD44 is a transmembrane proteoglycan that serves as a cell adhesion receptor and is involved in cell-cell and cell-matrix interactions, both key events in the pathogenesis of clinical and experimental glomerulonephritis. In addition, recent evidence suggests that the binding of cytokines to proteoglycans could regulate cytokine function. We have, therefore, studied the expression of CD44 by mesangial cells in culture and in experimental (Thy 1.1 model) and human glomerulonephritis. Mesangial expression of CD44 detected by immunohistochemistry was markedly increased four days after induction of the Thy 1.1 model, coinciding with the peak of mesangial cell proliferation and macrophage infiltration. Analysis of 92 human renal biopsies by immunohistochemistry showed that CD44 expression by infiltrating cells within the glomerulus, in focal interstitial infiltrates and within the interstitium (interstitial fibroblasts, and extracellular matrix), was significantly increased in biopsies with a greater degree of histological damage. There was, however, no increase in mesangial staining in diseased kidneys as compared with control sections. In contrast, cultured human mesangial cells expressed CD44 strongly when assayed by immunohistochemistry, immunoprecipitation and Northern blotting. CD44, therefore, is an example of a protein strongly expressed by mesangial cells in vitro and weakly or not at all in vivo, but which is up-regulated in a disease model. In human disease, however, little expression was detected within the glomerular mesangium, which may be related to the greater proliferation and more profound disruption of mesangial architecture seen in the Thy 1.1 model. CD44 expression by infiltrating cells and by components of the interstitium could, however, play an important role in the pathogenesis of chronic progressive renal disease in humans.

Observer variability in histopathological reporting of non-small cell lung carcinoma on bronchial biopsy specimens

AIMS

To evaluate the ability of histopathologists to sub-classify non-small cell lung carcinomas on bronchial biopsy material using the current World Health Organisation (WHO) classification.

METHODS

Twelve histopathologists each reviewed 100 randomly selected bronchial biopsy specimens which had originally been reported as showing non-small cell lung carcinoma. For each case, two sections were circulated, one stained by haematoxylin and eosin and the other by a standard method for mucin (alcian blue/periodic acid Schiff). The participants were allowed to indicate their degree of confidence in their classification of each case. A standard proforma was completed and the results were analysed using kappa statistics.

RESULTS

Where the participants were confident in their classification, they were actually quite good at sub-classifying the non-small cell carcinoma sections (kappa = 0.71, standard error = 0.058). Overall, however, the results were only fair (kappa = 0.39, standard error = 0.034).

CONCLUSIONS

The majority of non-small cell lung carcinomas can be correctly categorised on adequate bronchial biopsy material. Where a confident diagnosis was made, both squamous carcinoma (kappa = 0.73) and adenocarcinoma (kappa = 0.83) were well recognised.

Adhesion molecule interactions in human glomerulonephritis: importance of the tubulointerstitium

Infiltration of leukocytes into glomerular and interstitial regions of the kidney is a key event in the pathogenesis of human glomerulonephritis. This process is mediated by specific adhesion molecules, some of which are expressed in a coordinated fashion following endothelial cell activation. We have assessed the pattern of expression of the selectins (E, P and L), and the counter-receptors (LFA-1 and ICAM-1, and VLA-4 and VCAM-1 in 119 renal biopsies using sequential sections, and have correlated this with the degree of histological damage (tubular atrophy and interstitial fibrosis) and the intensity of the macrophage infiltrate. Sections were stained with the monoclonal antibodies using a standard alkaline phosphatase anti-alkaline phosphatase (APAAP) technique. There were strong correlations between the following: (1) expression of LFA-1, VLA-4, and L-selectin in the periglomerular region, interstitium and in focal interstitial infiltrates and the presence of macrophages in these regions; (2) de novo tubular expression of ICAM-1 and VCAM-1; (3) staining for ICAM-1 and VCAM-1 on focal cellular infiltrates within the interstitium; and (4) staining for E- and P-selectin on extraglomerular endothelium. These are also strongly correlated with the degree of chronic histological damage. There was, however, no correlation between glomerular expression of adhesion molecules or glomerular macrophage infiltration and chronic histological damage. Although expression of VCAM-1 by the glomerular mesangium was strongly correlated with the presence of cells staining for VLA-4 within the glomerulus, glomerular expression of adhesion molecules correlated poorly with their expression in other sites. These results show that coordinated up-regulation of adhesion molecule expression in the tubulointerstitium is associated with interstitial fibrosis and tubular atrophy and may contribute, therefore, to the progression of renal disease.

Ecstasy induced hepatitis mimicking viral hepatitis

Three cases of jaundice after ingestion of 3,4-methylenedioxymetamphetamine (MDMA), known as 'ecstasy', are reported and the complications associated with the misuse of this drug, which was initially misrepresented as 'safer than alcohol' are described. Ingestion of 'ecstasy' should be considered when investigating unexplained jaundice in younger patients.

Phenotypic analysis of the glomerular and periglomerular mononuclear cell infiltrates in the Thy 1.1 model of glomerulonephritis

BACKGROUND

The phenotype of macrophages invading the mesangium and periglomerular region has not been described in experimental mesangial proliferative glomerulonephritis, although it has implications for the mechanism of entry of these cells into these locations and their function once there. We have, therefore, determined the phenotype of the periglomerular leukocytic infiltrate in the Thy 1.1 model of mesangial proliferative glomerulonephritis and compared it with that of cells invading the mesangium.

EXPERIMENTAL DESIGN

The Thy 1.1 model was induced in Lewis rats, and sections were taken at 1 hour and at 1, 4, 9, 30, and 90 days postinduction. Immunohistochemistry was performed using monoclonal antibodies against macrophage markers (ED-1, CD4, RT1-B, and ED-2), chains of the beta 2 integrins (CD18, CD11a, and CD11b), T and B cell markers (CD8, T cell receptor, interleukin-2 receptor, and MRC OX33), and markers of mesangial cell proliferation (proliferating cell nuclear antigen, alpha-smooth muscle actin). Sections were compared with those obtained from control animals.

RESULTS

In untreated rats, a striking resident periglomerular macrophage population (phenotype ED-1-ve ED-2-ve CD4+ve RT1-B+ve CD18+ve CD11a+ve CD11b+ve) was found, confirming a previous report. From 24 hours postinduction, this resident macrophage population was supplemented by a population whose predominant phenotype (ED-1+ve ED-2-ve CD4+ve RT1-B+ve CD18+ve CD11a+ve CD11b+ve) was identical to that of macrophages infiltrating the mesangium. Both infiltrates peaked at 4 days and returned to base-line levels by 1 to 3 months. There was no significant lymphocyte infiltrate within the glomerulus and only a minimal periglomerular T cell infiltrate.

CONCLUSIONS

These data show, first, that disease limited to the mesangium can lead directly to periglomerular macrophage infiltration. Second, the presence of CR3 (i.e., CD11b and CD18) and LFA-1 (i.e., CD11a and CD18) on the macrophage infiltrate indicates that both ligands are important for cells to enter the mesangium and periglomerular areas. Third, the marked phenotypic and temporal similarities between the mesangial and periglomerular macrophage infiltrates suggests that a common factor(s) is involved in their pathogenesis. Finally, expression of RT1-B (Ia) but not ED-2 is reported to be typical of interstitial dendritic cells rather than tissue macrophages, suggesting a unique function for the glomerular and periglomerular macrophage infiltrate in this model.

Observer variability in histopathological reporting of malignant bronchial biopsy specimens

AIMS

To evaluate the ability of histopathologists to classify lung carcinomas on bronchial biopsy material using the current World Health Organisation (WHO) classification.

METHODS

Eleven histopathologists each reviewed 100 randomly selected bronchial biopsy specimens which had originally been reported as showing lung carcinoma. A single haematoxylin and eosin stained section from each case was circulated and a standard proforma completed. These were analysed using kappa statistics.

RESULTS

The histopathologists were excellent at distinguishing between small cell and non-small-cell carcinoma kappa = 0.86), but not so good at subclassifying the non-small cell carcinoma group kappa = 0.25).

CONCLUSIONS

The clinically important distinction between small cell and non-small cell carcinoma of the lung is reliably made by competent histopathologists even on limited material.

Observer variability in the histopathological reporting of abnormal rectal biopsy specimens

AIMS

To study the consistency of reporting of abnormal rectal biopsy specimens, especially in the differentiation of inflammatory bowel disease from other causes of abnormality.

METHODS

Sixty rectal biopsy specimens were identified from patients presenting with bloody diarrhoea. These were then circulated to the 11 consultant pathologists in the study who filled in a proforma with a list of 12 diagnostic categories and 22 features.

RESULTS

Forty one of the 60 cases were examples of inflammatory bowel disease. In 33 of these cases nine or more pathologists had made the diagnosis. Further categorisation into ulcerative colitis and Crohn's disease showed better recognition of ulcerative colitis. In the 19 cases of non-inflammatory bowel disease recognition of pseudomembranous colitis and solitary rectal ulcer syndrome was good, but the results were poorer in the case of infective colitis.

CONCLUSION

The findings suggest that a group of consultant pathologists can differentiate between inflammatory bowel disease and other causes of an abnormal rectal biopsy specimen and can also recognise pseudomembranous colitis and solitary rectal ulcer syndrome satisfactorily.

Urokinase-plasminogen activator is synthesized in vitro by human glomerular epithelial cells but not by mesangial cells

The plasmin protease system may have a role in maintaining the patency of renal tubules and in regulating matrix degradation within the glomerulus. Urokinase-plasminogen activator (u-PA) is a serine protease which plays an important part in the regulation of plasmin production from plasminogen. The synthesis of u-PA by cultured human glomerular cells, in particular mesangial cells, is controversial. The present study describes the presence of u-PA in supernatants of pure cultures of human glomerular epithelial cells (EC), cocultures of EC and human mesangial cells (MC) and whole glomeruli, but not within pure cultures of MC. To confirm the synthesis of u-PA mRNA in glomerular EC, cocultures of EC and MC were tested by in situ hybridization with u-PA antisense and sense digoxigenin-labeled RNA probes. Cytoplasmic localization of u-PA mRNA was demonstrated only in the EC, thus confirming the absence of synthesis of u-PA by human mesangial cells in culture.

Membranous nephropathy and granulomatous interstitial nephritis in sarcoidosis

A 56-year-old woman developed nephrotic syndrome in association with pulmonary sarcoidosis. Renal biopsy revealed both granulomatous interstitial nephritis and membranous nephropathy. Treatment with steroids resulted in a decrease in proteinuria and there was no deterioration in renal function over a subsequent period of 10 months. This case provides further evidence that secondary membranous nephropathy associated with sarcoidosis should be treated with steroids.

An immunohistological study of epidermal growth factor receptor and neu receptor and neu receptor expression in proliferative glomerulonephritis

Many forms of glomerulonephritis including IgA nephropathy are characterized by mesangial cellular proliferation. Since epidermal growth factor is a potent mitogen for cultured human mesangial cells, we have attempted to localize and quantify the expression of its receptor in normal and abnormal renal biopsies using immunohistochemistry. Using a particular antibody (Amersham, clone EGFR1), the epidermal growth factor receptor (EGF-R) was shown to be predominantly localized in the mesangium of the glomerulus. Visual estimates of intensity of staining suggested that expression of this receptor may be increased in some IgA disease patients with mesangial proliferative glomerular lesions. The neu receptor which has a 50% homology with EGF-R was, however, absent from the glomerulus and cultured mesangial cells did not express detectable levels. Expression of EGF-R by cultured mesangial cells, as assessed by immunostaining, was weak and it was not possible to induce detectable upregulation using different cytokines. The factors leading to increased expression of EGF-R in glomerulonephritis, therefore, remain unknown. Our findings suggest that signalling via EGF-R may play a role in the pathogenesis of proliferative glomerulonephritis. Despite its homology with EGF-R, the neu receptor is unlikely to have similar importance.

The reversal of experimental cyclosporin A nephrotoxicity by thromboxane synthetase inhibition

The ability of thromboxane synthetase inhibition to reverse acute cyclosporin A (CsA)-induced nephrotoxicity in the rat was investigated. CsA administration (50 mg/kg/day p.o. for 14 days) to male Sprague-Dawley rats caused a significant 50% decline in creatinine clearance rates, an increase in N-acetyl-beta-D-glucosaminidase (NAG) enzymuria and renal tubulointerstitial damage by day 14. These changes were associated with a 5-6-fold increase in urinary thromboxane B2 excretion (from pretreatment values of 28.1 +/- 7.9 to 122.6 +/- 38.9 and 165.8 +/- 39.0 eta g/24 hr body weight on days 7 and 14, respectively). Excretion rates of 6-keto-prostaglandin F1 alpha and prostaglandin E2 were, however, unaffected by CsA administration. Co-treatment with a thromboxane synthetase inhibitor (CGS 12970; 8-[3-methyl-2-(3-pyridyl)-1-indolyl]-octanoic acid) from day 7 (10 mg/kg/day) normalized thromboxane B2 excretion, resulted in creatine clearance rates which were similar to pretreatment values on days 10 and 14, reduced NAG enzymuria on day 10 and prevented acute proximal tubular vacuolation. However, the severity of chronic CsA nephrotoxicity, namely chronic tubular damage and microcalcification at the corticomedullary junction, was not diminished by the thromboxane synthetase inhibition. These results demonstrate that (i) elevated thromboxane synthesis plays an important role in the development of acute CsA nephrotoxicity and (ii) that different and/or additional mechanisms are involved in the pathogenesis of chronic nephrotoxicity.

Secondary polycythaemia associated with idiopathic membranous nephropathy

A 44-year-old man developed idiopathic membranous nephropathy and true secondary polycythaemia. With advancing azotemia, polycythaemia gradually resolved and venesection was no longer required. Only 2 cases of polycythaemia associated with membranous nephropathy have been reported previously. Secondary polycythaemia is a rarely reported association of membranous nephropathy and may increase the risk of thromboembolism, which might be prevented with venesection.

Monoclonal antibodies to cultured human glomerular mesangial cells. I. Reactivity with haematopoietic cells and normal kidney sections

The aim of this study was to produce monoclonal antibodies to cultured human glomerular mesangial cells in order to obtain specific markers for these cells and to aid the study of their function. Using standard monoclonal antibody techniques, 29 hybridomas producing antibodies directed to cultured mesangial cells were obtained. Most of these antibodies were not reactive with normal or neoplastic haematopoietic cell lines by flow cytometry. Fourteen of the 29 culture supernatants bound to various components of normal human kidney sections stained by the alkaline phosphatase/anti-alkaline phosphatase (APAAP) method. Ten of these supernatants reacted with components within the glomerulus, with six binding to the mesangium. These studies suggest that (1) mesangial cells in culture may show significant de-differentiation, because most supernatants which reacted with mesangial cells in culture did not do so in tissue sections; (2) antibodies reactive with haematopoietic cells may not detect the majority of immunogenic surface antigens on cells in tissues; and (3) some of the antibodies which we have produced may prove to be useful markers for mesangial cells in glomerular disease.

Effect of thromboxane synthetase inhibition and angiotensin converting enzyme inhibition on acute cyclosporin A nephrotoxicity

One component of cyclosporin A (CsA) nephrotoxicity is thromboxane (Tx) A2 induced renal vasoconstriction. This study was designed to investigate whether coadministration of angiotensin converting enzyme inhibitors (ACEI) and thromboxane synthetase inhibition (TSI) could act synergistically to improve the glomerular filtration rate in CsA treated animals. CsA administration (50 mg/kg/day p.o.) to Sprague-Dawley rats for 14 days caused a significant decline in creatinine clearance (CCR), an increase in N-acetyl-beta-D-glucosaminidase (NAG) enzymuria and renal tubulointerstitial damage. These changes were associated with a ten-fold increase in urinary TxB2 excretion (from pretreatment values of 17.2 +/- 6.0 ng/day to 174.9 +/- 65.4 ng/day on day 14). Treatment with TSI normalized TxB2 excretion; this was associated with partial protection against CsA induced changes in CCR and NAG enzymuria and the complete prevention of acute proximal tubular vacuolation. However, the coadministration of both TSI and ACEI removed the protective effects exerted by TSI alone and resulted in elevated urinary TxB2 levels similar to those observed in other CsA treated groups. Treatment with ACEI alone did not affect CsA nephrotoxicity. We suggest that elevated TxB2 synthesis is in part responsible for some aspects of renal functional and morphological damage, but that CsA nephrotoxicity is multifactorial and may result from direct cellular toxicity in addition to vascular changes.

Drug metabolism and viability studies in cryopreserved rat hepatocytes

Rat hepatocytes were cryopreserved optimally by freezing them at 1 degrees C/min to -80 degrees C in cryoprotectant medium containing either 20% (v/v) dimethylsulfoxide (Me2SO) and 25% (v/v) fetal calf serum in Leibowitz L15 medium (Me2SO cryoprotectant) or 25% (v/v) vitrification solution (containing Me2SO, acetamide, propylene glycol and polyethylene glycol) in Leibowitz L15 medium (VS25). The VS25 solution was superior for maintaining viability during short-term storage (24-48 hr) but was slightly toxic during longer storage periods (7 days). Although thawed cells were 40-50% viable on ice after cryopreservation, their viability fell rapidly during incubation in suspension at 37 degrees C. This decline in viability occurred more rapidly after freezing in Me2SO cryoprotectant than in VS25 and was associated with extensive intracellular damage and cell swelling. The loss in viability at 37 degrees C does not appear to be due to ice-crystal damage as it occurred in cells stored at -10 degrees C (above the freezing point of the cryoprotectants) and it may be due to temperature/osmotic shock. Both cryoprotectant media were equally efficient at preserving enzyme activities in the hepatocytes over 7 days at -80 degrees C. Cytochrome P450 and reduced glutathione content and the activities of the microsomal enzymes responsible for aminopyrine N-demethylation and epoxide hydrolysis were well maintained over 7 days storage. In contrast, the cytosolic enzymes glutathione-S-transferase and glutathione reductase were markedly labile during cryopreservation. Cytosolic enzymes may be more susceptible to ice-crystal damage, whereas the microsomal membrane may protect the enzymes which are embedded in it.

Light and electron microscopic demonstration of immune deposits in renal tissue

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The effects of cyclosporin A on glucose homeostasis and the kidney in the normal rat

The effects of administering cyclosporin A (CsA), for periods of up to 84 days, on glucose homeostasis and renal function were studied in adult male Sprague-Dawley rats. Marked glucose intolerance was demonstrated at a variety of drug doses, accompanied in the longer term by hyperglycaemia. Early on and at high CsA dose, the abnormal islet cell function was accompanied by islet cell vacuolation; in the long-term dose groups, more chronic structural islet changes were present. Although abnormalities in renal function and structure were noted during this study, they were not directly related to the pancreatic changes observed.

Evaluation of 3-fucosyl N-acetyllactosamine antibody staining in histological assessment of CIN

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Observer variability in histopathological reporting of transitional cell carcinoma and epithelial dysplasia in bladders

Sections from 90 urinary bladder biopsy specimens were examined by 11 consultant histopathologists with varying experience to determine the appropriateness of existing pathology terminology. Analysis with kappa statistics showed fair to good agreement in the grading and staging of transitional cell carcinoma. There was also reasonable agreement in the diagnosis of high grade dysplasia in random biopsy specimens from the urothelium adjacent to the neoplasm, but very poor agreement for lesser degrees of dysplasia. It is concluded that the present classification of bladder carcinomata is reliable and that pathologists can determine stage with a high degree of reproducibility and grade with a fair degree of reproducibility.

Observer variability in histopathological reporting of cervical biopsy specimens

Sections from 100 cervical biopsy specimens were studied by 12 consultant histopathologists to determine the robustness of the existing pathology terminology and classification. Analysis by kappa statistics showed good agreement in the diagnosis of CIN 3 and squamous carcinoma but an inability to distinguish accurately between the lesser grades of CIN. It is recommended that the classification be changed to low grade (present CIN 1 and 2) and high grade (present CIN 3) categories alone. There was very poor agreement in the identification of cellular changes associated with human papilloma virus (HPV) infection.

Influence of the hepatic drug-metabolizing enzyme-inducer phenobarbitone on cyclosporine nephrotoxicity and hepatotoxicity in renal-allografted rats

We have investigated the influence of phenobarbitone ([PB]; 40 mg/kg/day), an inducer of hepatic drug metabolism, on high-dose cyclosporine ([CsA] 40 mg/kg/day) nephrotoxicity in normal Lewis (Lew) and renal allografted (DA X Lew F1----Lew) rats of both sexes. In untreated normal animals, CsA nephrotoxicity, assessed biochemically and histologically, in terms of acute and chronic renal structural damage, was consistently greater in male than in female rats. The capacity of PB to induce CsA metabolism was accompanied in normal rats by reductions in nephro- and hepatotoxicity and by prolonged survival of both female and male rats. Similar reductions in CsA-induced renal functional impairment and acute tubular cell injury were achieved in transplanted female (but not male) animals by concomitant PB administration. Continuous PB treatment in transplanted rats was, however, associated with the appearance of hepatic necrosis. While this effect of PB, and its failure to reduce CsA-induced chronic renal damage mitigate against its prospective value in reversing CsA toxicity, PB may nevertheless prove valuable in assessing further the role of drug metabolism in the pathogenesis of CsA nephrotoxicity.

Drug hypersensitivity causing granulomatous interstitial nephritis

In association with treatment for pharyngitis, a 47-year-old white man developed a systemic illness with fever, myalgia, episcleritis, hemoptysis, pleurisy, eosinophilia, and renal impairment. Renal biopsy revealed granulomatous interstitial nephritis, which resolved due to no specific treatment other than withdrawing all medication. Both the severe systemic manifestations and spontaneous recovery are unusual in association with drug-induced granulomatous nephritis. The drugs that may have caused the reaction included dihydrocodeine, phenylpropanolamine, erythromycin, and amoxycillin. Although the latter three drugs have been previously implicated in the development of interstitial nephritis, there have been no previous reports of granulomatous interstitial nephritis with any of these drugs.

Lithium clearance measurements as an indication of cyclosporin A nephrotoxicity in the rat

1. Measurements of the rate of lithium clearance, which provides an estimate of proximal renal tubular iso-osmotic reabsorption (i.e. sodium and H2O), were used to study H2O and electrolyte reabsorption during the development of cyclosporin A (CsA) induced nephrotoxicity. 2. CsA, administered daily by gavage at 50 mg/kg body weight, produced a nephrotoxicity which was characterized by reductions in the clearance rates of creatinine, sodium and potassium, and increased glycosuria, enzymuria and urine flow rate. 3. Decreased lithium clearance rate and increased proximal iso-osmotic reabsorption accompanied significant reductions in creatinine clearance rate. Absolute proximal tubular reabsorption, however, was not affected by CsA administration. 4. Reductions in the absolute distal tubular reabsorption of sodium, potassium and H2O were also observed. 5. Alterations in renal tubular function occur early in the development of CsA nephrotoxicity as a result of both direct proximal tubulotoxicity and an effect on the afferent arteriole. 6. Measurements of the rate of lithium clearance may be a useful adjunct to the diagnosis of CsA nephrotoxicity.

Prophylactic and therapeutic effects of ciclosporin A in murine Schistosomiasis mansoni: studies on bisexual and unisexual infections and the hepatic inflammatory response

Ciclosporin A (CsA), administered subcutaneously as 5 daily injections of 50 mg.kg-1, reduced the numbers of Schistosoma mansoni perfused from MF1 mice at 7 weeks post-infection. The timing of drug administration revealed that the antischistosomal effects were greater when CsA treatment coincided with or was within a few days of infection with the parasite. CsA exerted a clear prophylactic effect, which decreased with time and was virtually abolished by 4 months pre-infection. Adult worms treated in vivo were partially susceptible to CsA. In addition to its antiparasite action, CsA reduced hepatosplenomegaly due to schistosomiasis and diminished the granulomatous inflammatory response of mice to parasite eggs in the liver. The mode of action of CsA is not understood but evidence is presented that supports the proposition that the antiparasite effects are perhaps host-mediated.