Dehydroepiandrosterone reduces expression of glycolytic and gluconeogenic enzymes in the liver of male and female rats

The in vivo effect of dehydroepiandrosterone (DHEA) on hepatic glycogen content and on glucose metabolizing enzymes was investigated in male and female Sprague-Dawley rats treated with 0.6% (w/w) DHEA in the diet for 3, 7, 14, 28 and 140 days. The glycolytic enzymes studied (glucokinase, hexokinase, pyruvate kinase) showed a significant persistent decrease in activity in both sexes after 3-7 days of treatment. Gluconeogenic enzymes (glucose-6-phosphatase, fructose-1,6-bisphosphatase) were increased after 3 days, but decreased after 7-14 days. Glycolytic enzymes showed a stronger reduction than gluconeogenic enzymes. Females were slightly more affected than males. Glucose-6-phosphate dehydrogenase was unchanged in females, but increased in males. Glycogen content and the activity of glycogen phosphorylase were reduced after 3 days of treatment. mRNA analysis of glucokinase and phosphorylase indicated that these enzyme alterations were accompanied by reduced transcriptional expression, while glucose-6-phosphate dehydrogenase mRNA levels were unchanged. Withdrawal of DHEA from 4 week-treated rats was associated with an almost complete reversibility of the enzyme alterations after 2 weeks. After long-term treatment (140 days) glucokinase, glucose-6-phosphatase and fructose-1,6-bisphosphatase activities were no longer altered. Since DHEA treatment affects the key enzymes of glucose metabolic pathways in the same sense, it is suggested that DHEA does not regulate individual enzymes but rather common regulatory factors or signalling pathways.

Anti-atherosclerotic effect of microbial hyaluronate lyase from group B streptococci

The effect of the microbial hyaluronic acid splitting enzyme hyaluronate lyase produced by Streptococcus agalactiae was investigated in vitro in human atherosclerotic plaque specimens and in vivo on Watanabe heritable hyperlipidaemic rabbits (WHHL) as an animal model for familiar hypercholesteraemia. The in vitro presence of the enzyme caused a partial destruction of the atherosclerotic plaque surfaces as well as releasing of glucuronic acid and solid calcium-containing materials from pieces of atherosclerotic plaques in human arteries. Accordingly hyaluronic acid seems to be the main component for anchoring of calcium deposits on the plaque surfaces. Repeated intravenous injections of hyaluronate lyase in WHHL rabbits resulted in a tendency of decreased formation of atherosclerotic plaques. The observed effects are discussed to be primary the result of the splitting of hyaluronic acid in the vessels.

Clinical and histopathological features of dextran sulfate sodium induced acute and chronic colitis associated with dysplasia in rats

We examined the clinical and histopathological features of the dextran sulfate sodium (DSS) induced acute and chronic colitis in rats as a model for studying basic biology of the inflamed colonic mucosa. Acute colitis was induced in male Wistar rats by 4 days (AI) or 7 days (AII) of oral 5% (wt/vol) DSS (mol. wt. 54,000) in their drinking water. Chronic colitis was induced in 8 experimental groups: CI=7 days DSS followed by 10 days water (=one cycle); CII=two cycles; CIII to CVIII (three to eight cycles) received only 4 days 5% DSS followed by 10 days drinking water. The entire colons were examined histologically; dysplasia was graded as: indefinite/probably negative for dysplasia, indefinite/probably positive for dysplasia, low-grade dysplasia, or high-grade dysplasia. The earliest clinical findings in the acute colitis group over 4 days occurred on day 2 (hemoccult positive stools, loose stools or diarrhea and weight loss). The maximal disease activity was noted on day 7 accompanied by a 53% mortality rate. The histological inflammation scores were significantly higher on day 7 than on day 4. All rats had extensive ulcerations predominantly in the rectum and cecum. The number of rats having ulcerations was markedly lower in the chronic colitis groups. The majority (75%) of the crypt lesions suspicious for dysplasia were classified as mucosa indefinite/probably negative for dysplasia. We classified 18 crypt lesions as low-grade dysplasia and one lesion as high-grade dysplasia (after eight cycles). No invasive carcinoma was observed. Most low-grade dysplasias (83%) occurred after five cycles of DSS/water, located mostly in the rectum (44%) and colon transversum (33%). Our findings suggest that the DSS colitis model in rats may be an interesting model for studying the sequence chronic inflammation-dysplasia in human ulcerative colitis. Further long-term studies with the present DSS colitis model in rats might also prove it as a reliable model to study the sequence high-grade dysplasia and colitis associated-cancer.

Sequence analysis of the mismatch repair gene hMSH6 in the germline of patients with familial and sporadic colorectal cancer

To evaluate the involvement of hMSH6 in colorectal cancer, the complete coding sequence and flanking intron regions of the gene were analyzed by DNA sequencing in 10 patients fulfilling Bethesda Guidelines for colorectal tumors and 10 patients with sporadic colorectal carcinoma. In addition, 10 mono- and 10 dinucleotide repeat markers were analyzed for microsatellite instability. A protein-truncating T insertion at codon 218 was identified in the index person of a hereditary non-polyposis colorectal cancer (HNPCC)-like kindred and was accompanied by a somatic T deletion in the tumor. The tumor of this patient was positive for mono- but negative for dinucleotide repeat instability and lacked allelic losses at loci frequently affected in colorectal carcinomas. A novel amino acid change, F340S, was found in a patient with sporadic colon and breast cancer and leukemia but was not detected in 246 chromosomes from healthy anonymous blood donors. In addition, we describe 2 silent and 15 intronic sequence variants not previously reported. Although the frequency is low, we present further evidence for hMSH6 germline mutations that predispose patients to HNPCC-like phenotypes and suggest that mono- and dinucleotide repeat instability testing may be useful for distinguishing between individuals harboring an hMSH2 or hMLH1 mutation and a mutation of the hMSH6 gene.

[Correlation between histological and molecular mechanisms of carcinogenesis in stomach cancer]

Since gastric cancer is an exceptional heterogeneous tumor conflicting results have been obtained about the relationship between genotype and phenotype. From the molecular point of view gastric carcinoma diffuse type forms a distinct entity which is microsatellite stable, has almost no p53 mutations and exhibits in at least half of the cases mutations in the E-cadherin gene. In contrast, all other gastric carcinomas comprise a heterogeneous group of which about one third exhibits microsatellite instability (MSI) but no p53 protein stabilization or gene mutations. These tumors are either of pure intestinal (glandular) type or show large solid (medullary) tumor cell clusters. Thereby, in sporadic gastric cancer MSI is caused by loss of hMLH1 expression due to hypermethylation of the promotor region rather than by mutation of the gene itself. Tumors that are microsatellite stable (MSS) and show p53 alterations are either intestinal (about 70%) or a mixed-type encompassing at least 5% glandular and poorly differentiated diffuse components (about 30%). Whereas pure diffuse type gastric cancer is unlikely to develop from intestinal type carcinoma, this may, however, be the case in some advanced mixed-type gastric cancers.

Sequence analysis of the mismatch repair gene hMSH6 in the germline of patients with familial and sporadic colorectal cancer

To evaluate the involvement of hMSH6 in colorectal cancer, the complete coding sequence and flanking intron regions of the gene were analyzed by DNA sequencing in 10 patients fulfilling Bethesda Guidelines for colorectal tumors and 10 patients with sporadic colorectal carcinoma. In addition, 10 mono- and 10 dinucleotide repeat markers were analyzed for microsatellite instability. A protein-truncating T insertion at codon 218 was identified in the index person of a hereditary non-polyposis colorectal cancer (HNPCC)-like kindred and was accompanied by a somatic T deletion in the tumor. The tumor of this patient was positive for mono- but negative for dinucleotide repeat instability and lacked allelic losses at loci frequently affected in colorectal carcinomas. A novel amino acid change, F340S, was found in a patient with sporadic colon and breast cancer and leukemia but was not detected in 246 chromosomes from healthy anonymous blood donors. In addition, we describe 2 silent and 15 intronic sequence variants not previously reported. Although the frequency is low, we present further evidence for hMSH6 germline mutations that predispose patients to HNPCC-like phenotypes and suggest that mono- and dinucleotide repeat instability testing may be useful for distinguishing between individuals harboring an hMSH2 or hMLH1 mutation and a mutation of the hMSH6 gene.

Molecular diagnostics of cancer predisposition: hereditary non-polyposis colorectal carcinoma and mismatch repair defects

Hereditary non-polyposis colorectal carcinoma accounts for 5-13% of all colorectal carcinomas and is inherited in a dominant fashion. Two different forms can be distinguished. Type I is restricted to colorectal cancers, whereas type II patients acquire acolorectal, endometrial, gastric, small intestinal and transitional carcinomas of the upper urinary tract. Germline mutations in the human mismatch repair genes (hMSH2, hMSH6, hMLH1, hPMS2) account for the majority of hereditary non-polyposis colorectal carcinoma. As a result of the mismatch repair deficiency, replication errors are not repaired, resulting in a mutator phenotype. Simple repetitive sequences (microsatellites) are especially prone to replication errors and analysis of their stability combined with immunohistochemical analysis of mismatch repair protein expression provides a rapid diagnostic strategy. For patients either (1) fulfilling the Amsterdam criteria for HNPCC, (2) with synchronous or metachronous hereditary non-polyposis colorectal carcinoma-related tumors, (3) with hereditary non-polyposis colorectal carcinoma-related tumors before the age of 45 and/or (4) with right sided CRC and mucinous, solid, or cribriform growth patterns, screening for mismatch repair deficiencies should be performed. The identification of colorectal cancers displaying a mutator phenotype has implications for both treatment and prognosis.

MLH1 promoter methylation and gene silencing is the primary cause of microsatellite instability in sporadic endometrial cancers

Defective DNA mismatch repair in human tumors leads to genome-wide instability of microsatellite repeats and a molecular phenotype referred to as microsatellite instability (MSI). MSI has been reported in a variety of cancers and is a consistent feature of tumors from patients with hereditary non-polyposis colorectal cancer. Approximately 20% of cancers of the uterine endometrium, the fifth most common cancer of women world-wide, exhibit MSI. Although the frequency of MSI is higher in endometrial cancers than in any other common malignancy, the genetic basis of MSI in these tumors has remained elusive. We investigated the role that methylation of the MLH1 DNA mismatch repair gene plays in the genesis of MSI in a large series of sporadic endometrial cancers. The MLH1 promoter was methylated in 41 of 53 (77%) MSI-positive cancers investigated. In MSI-negative tumors on the other hand, there was evidence for limited methylation in only one of 11 tumors studied. Immunohistochemical investigation of a subset of the tumors revealed that methylation of the MLH1 promoter in MSI-positive tumors was associated with loss of MLH1 expression. Immunohistochemistry proved that two MSI-positive tumors lacking MLH1 methylation failed to express the MSH2 mismatch repair gene. Both of these cancers came from women who had family and medical histories suggestive of inherited cancer susceptibility. These observations suggest that epigenetic changes in the MLH1 locus account for MSI in most cases of sporadic endometrial cancers and provide additional evidence that the MSH2 gene may contribute substantially to inherited forms of endometrial cancer.

hMSH5: a human MutS homologue that forms a novel heterodimer with hMSH4 and is expressed during spermatogenesis

MutS homologues have been identified in nearly all organisms examined to date. They play essential roles in maintaining mitotic genetic fidelity and meiotic segregation fidelity. MutS homologues appear to function as a molecular switch that signals genomic manipulation events. Here we describe the identification of the human homologue of the Saccharomyces cerevisiae MSH5, which is known to participate in meiotic segregation fidelity and crossing-over. The human MSH5 (hMSH5) was localized to chromosome 6p22-21 and appears to play a role in meiosis because expression is induced during spermatogenesis between the late primary spermatocytes and the elongated spermatid phase. hMSH5 interacts specifically with hMSH4, confirming the generality of functional heterodimeric interactions in the eukaryotic MutS homologue, which also includes hMSH2-hMSH3 and hMSH2-hMSH6.

[Aspirin suppresses microsatellite instability]

Nonsteroidal anti-inflammatory drugs (NSAIDs) exhibit cancer preventive effects and have been shown to induce regression of adenomas in FAP patients. In order to elucidate the probable underlying mechanism, the effect of NSAIDs on mismatch repair related microsatellite instability was investigated. Six colorectal cancer cell lines all but one deficient for human mismatch repair (MMR) genes were examined for microsatellite instability (MSI) prior and after treatment with Aspirin or Sulindac. For rapid in vitro analysis of MSI a microcloning assay was developed by combining Laser microdissection and random (PEP-) PCR prior to specific MSI-PCR. Effects of NSAIDs on cell cycle and apoptosis were systematically investigated by using flow cytometry and cell-sorting. MSI frequency in cells deficient of MMR genes (hMSH2, hMLH1, hMSH6) was markedly reduced after long-term (> 10 weeks) NSAID treatment. This effect was reversible, time- and concentration dependent. However, in the hPMS2 deficient endometrial cancer cell line (HEC-1-A) the MSI phenotype kept unchanged. According to cell sorting, non-apoptotic cells were stable and apoptotic cells were unstable. These results suggest that aspirin/sulindac induces a genetic selection for microsatellite stability in a subset of MMR-deficient cells and may thus provide an effective prophylactic therapy for HNPCC related colorectal carcinomas.

Tufted angioma

Tufted angioma is a rare, slow growing, benign, vascular tumour. We describe two young male patients, each with a solitary erythematous plaque on the lateral aspect of the chest. In one case, the cutaneous lesion had been present since birth, in the other the tumour developed at the age of ten. Clinically appearing as a reddish, livid, partly papulous plaque, on histological examination they showed typical features of small, circumscribed, angiomatous lobules, particularly in the reticular layer of the dermis. These lobules were composed of poorly canalized, endothelial-lined vessels and solid regions. Cellular atypia and irregular mitotic figures were not observed. We report on our experience with s.c. interferon alpha treatment, in one case leading to a partial remission. Considering the differential diagnoses of malignant angiomatous tumours such as angiosarcoma or Kaposi's sarcoma, the awareness of the possibility of tufted angioma, which is a benign vascular proliferation, is of paramount importance.

Aspirin suppresses the mutator phenotype associated with hereditary nonpolyposis colorectal cancer by genetic selection

Nonsteroidal anti-inflammatory drugs (NSAIDs) are well-known cancer preventives, which have been largely attributed to their antiproliferative and apoptosis-inducing activities. In this study, we show that microsatellite instability (MSI) in colorectal cancer cells deficient for a subset of the human mismatch repair (MMR) genes (hMLH1, hMSH2, and hMSH6), is markedly reduced during exposure to aspirin or sulindac [or Clinoril, which is chemically related to indomethacin (Indocin)]. This effect was reversible, time and concentration dependent, and appeared independent of proliferation rate and cyclooxygenase function. In contrast, the MSI phenotype of a hPMS2-deficient endometrial cancer cell line was unaffected by aspirin/sulindac. We show that the MSI reduction in the susceptible MMR-deficient cells was confined to nonapoptotic cells, whereas apoptotic cells remained unstable and were eliminated from the growing population. These results suggest that aspirin/sulindac induces a genetic selection for microsatellite stability in a subset of MMR-deficient cells and may provide an effective prophylactic therapy for hereditary nonpolyposis colorectal cancer kindreds where alteration of the hMSH2 and hMLH1 genes are associated with the majority of cancer susceptibility cases.

[Molecular cancer disposition diagnosis exemplified by colorectal carcinoma. What is the contribution of pathology?]

During the last few years, the molecular basis of several cancer predisposition syndromes has been discovered which offers new tools for cancer prevention and early detection. This will be demonstrated in one of the most frequent hereditary cancer syndromes, namely the hereditary nonpolyposis colorectal cancer (HNPCC) which accounts for about 5% to 8% of CRC. Thereby, families with exclusively CRC (Lynch type I syndrome) and those with extracolonic cancers especially of endometrium, stomach, small bowel and upper urinary tract (Lynch type II syndrome) can be discriminated. At the molecular level, HNPCC is caused by germline mutations in one of the mismatch repair genes (hMSH2, hMLH1, hMSH6, hPMS2). Thus, nucleotide mispairings occurring particularly within simple repetitive genomic sequences (microsatellites) during replication are no longer be repaired properly and can be demonstrated by PCR as so-called microsatellite instability (MSI). Since more than 90% of HNPCC associated and only about 15% of sporadic CRC show MSI, this test is a useful tool for HNPCC screening. In case of a negative result HNPCC is highly unlikely. In positive cases (with > or = 2 out of 5 unstable defined microsatellite markers) the definite molecular diagnosis can only be obtained by sequencing the mismatch repair genes from the patient's blood or normal DNA. As immunohistochemistry reveals loss of hMSH2 or hMLH1 expression in most MSI positive CRC, these data provide useful information for the sequencing strategy. Molecular tumor screening by MSI test and immunohistochemistry is recommended in patients i.) with a positive family history (acc. to the Amsterdam criteria), ii.) suffering from multiple HNPCC related carcinomas, iii.) with HNPCC related cancer before 45 ys of age, and iv.) with right-sided CRC exhibiting medullary, signet-ring or mucinous differentiation. Finally, these tests as well as genetic counseling and treatment of the patient need to be done by an interdisciplinary approach. Thereby, the pathologist can substantially contribute to identify HNPCC related carcinomas either by clinical or morphological criteria and to initiate the molecular screening test.

[Late manifestation of a fatal Behçet's disease with cardiac involvement and lethal outcome]

HISTORY AND CLINICAL FINDINGS

One year before admission a 67-year-old man of German origin developed extensive ulcerations of the limbs, later also of the trunk and neck. In addition to recurrent oral aphthous ulcers it was associated with erythema nodosum and intermittent arthritis of the elbow knee and ankle joints. During the last month he also had dyspnoea. Echocardiography revealed a dilated cardiomyopathy (DCM). He was admitted because of the progressive skin disorder. Physical examination showed a disoriented man with dyspnoea, cyanosis of the lips and pretibial oedema. He had aphthous ulcers in the mouth and on the genitals. Adamant Behçet disease was suspected.

INVESTIGATIONS

Erythrocyte sedimentation rate was raised to 21/48 mm/h, white cell count to 15,800/microliter. Tests for HLA B5 and B27 were negative, skin biopsy revealed superficial necrotizing vasculitis of postcapillary venules.

TREATMENT AND COURSE

Initially high doses of prednisolone, 100 mg/d intravenously) and azathioprine (100 mg/d orally) were administered, and within a few days both the skin and cardiac changes had regressed. Prednisolone dosage was reduced and cyclosporin (350 mg/d) substituted for azathioprine. He was discharged in a markedly improved general condition and with only a few tibial ulcerations. 4 months later he had a severe recurrence with dramatic mucocutaneous involvement and rapidly deteriorating DCM, together with radiological signs of pneumonia. He died 4 months later.

INTERPRETATION

Although very rare, Behçet disease should even in the elderly patients be considered in the differential diagnosis: in the presence of appropriate symptoms cardiac involvement should be looked for.

Diagnostic microsatellite instability: definition and correlation with mismatch repair protein expression

Alterations of the length of simple repetitive genomic sequences (microsatellite instability, MSI) characterize a distinct mechanism of colorectal carcinogenesis. Such MSI has been found to be associated with hereditary nonpolyposis colorectal cancer (HNPCC) that involves mutation of the human mismatch repair genes hMSH2 and hMLH1 as well as many sporadic cancers of most tissue types. Although the study of MSI status is a useful tool for HNPCC screening and for the determination of tumor prognosis in sporadic cases of colorectal cancer, the reliability of MSI diagnosis is still a subject of debate. Here we have examined 58 primary colorectal tumors (selected from a cohort of 200) using 31 microsatellite markers that comprised the most frequent simple repeat types. The expression of the hMSH2 and hMLH1 mismatch repair proteins was studied by immunohistochemistry, and most patients were surveyed for at least 2 years. Reproducibility of gel interpretation, as well as diagnostic sensitivity and specificity of the MSI status, were determined. We found that unambiguous determination of band shifts as well as MSI diagnosis were closely related to the type of the marker repeat and that MSI could be subdivided into "high" MSI (>20% unstable loci), "low" MSI (<10% unstable loci), and microsatellite stable (0% unstable loci). One-half of the patients with high MSI tumors (n = 8) fulfilled either the Amsterdam criteria (n = 4), had at least one relative with HNPCC-related carcinoma (n = 2), or were diagnosed with colorectal cancer at an age below 45 years (n = 2). Fourteen of the 15 high MSI tumors had lost either hMSH2 (n = 8) or hMLH1 (n = 6) protein expression. In contrast, all of the low MSI tumors and the MSI-negative tumors displayed normal expression of hMSH2 and hMLH1. These studies provide a clear recommendation for the uniform use of a panel of 10 microsatellites and a definition of at least 40% instability (using these defined marker loci) in the diagnostic analysis of MSI.

Microsatellite instability analysis: a multicenter study for reliability and quality control

The molecular biology section of the Hereditary Non-Polyposis Colorectal Cancer study group-Germany, instituted a multicenter study to test the reliability and quality of microsatellite instability (MSI) analysis. Eight laboratories compared MSI analyses performed on 10 matched pairs of normal and tumor DNA from patients with colorectal carcinomas. A variety of techniques were applied to the detection of microsatellite changes: (a) silver and ethidium bromide staining of polyacrylamide gels; (b) radioactive labeling; and (c) automated fluorescence detection. The identification of highly unstable tumors and tumors without MSI was achieved in high concordance. However, the interpretation of the band patterns resulted in divergent classifications at several microsatellite marker loci for a large fraction of this tumor/normal panel. The data on more than 30 primers per case suggest that the enlargement of the microsatellite panel to more than 10 loci does not influence the results. In this study, cases with MSI in less than 10% of loci were classified as microsatellite stable, whereas MSI was diagnosed in cases with more than 40% of all markers unstable. We propose that a panel of five microsatellite loci consisting of repeats with different lengths should be analyzed in an initial analysis. When less than two marker loci display shifts in the microsatellite bands from tumor DNA, the panel should be enlarged to include an additional set of five marker loci. The number of marker loci analyzed as well as the number of unstable marker loci found should always be identified. These criteria should result in reports of MSI that are more comparable between studies.

Female embryonic lethality in mice nullizygous for both Msh2 and p53

The mutator hypothesis of tumorigenesis suggests that loss of chromosomal stability or maintenance functions results in elevated mutation rates, leading to the accumulation of the numerous mutations required for multistep carcinogenesis. The human DNA mismatch repair (MMR) genes are highly conserved homologues of the Escherichia coli MutHLS system, which contribute to genomic stability by surveillance and repair of replication misincorporation errors and exogenous DNA damage. Mutations in one of these MMR genes, hMSH2, account for about half of all cases of genetically linked hereditary non-polyposis colorectal cancer. Loss of function of p53 has also been proposed to increase cellular hypermutability, thereby accelerating carcinogenesis, although a clear role for p53 in genomic instability remains controversial. p53 is mutated frequently in a wide range of human cancers, including colonic tumours. Both Msh2- and p53-targeted knockout mice are viable and susceptible to cancer. Here we demonstrate that combined Msh2 and p53 ablation (Msh2-/-p53-/-) results in developmental arrest of all female embryos at 9.5 days. In contrast, male Msh2-/-p53-/- mice are viable, but succumb to tumours significantly earlier (t1-2 is 73 days) than either Msh2-/- or p53-/- littermates. Furthermore, the frequency of microsatellite instability (MSI) in tumours from Msh2-/-p53-/- mice is not significantly different than in Msh2-/- mice. Synergism in tumorigenesis and independent segregation of the MSI phenotype suggest that Msh2 and p53 are not genetically epistatic.

Poorly differentiated colonic adenocarcinoma, medullary type: clinical, phenotypic, and molecular characteristics

Clinicopathological evidence has accumulated that colorectal adenocarcinoma with minimal or no glandular differentiation constitutes two entities with different prognosis. In a series of 20 predominantly nonglandular, poorly differentiated adenocarcinomas, histological features, DNA content, p53 protein expression, Ki-ras mutation, and microsatellite instability were analyzed and correlated to the biology of the tumors. In addition, the presence of Epstein-Barr virus (EBV) transcripts was tested by RNA in situ hybridization and EBV DNA was demonstrated by nested polymerase chain reaction. Histologically, 13 tumors showed small uniform cells and 7 tumors showed large pleomorphic cells. Tumors with uniform cells exhibited more commonly an expansive growth pattern (69.2% versus 0%; P < 0.025) and a dense peritumor lymphoid infiltrate (84.6% versus 14.3%; P < 0.01) resembling their gastric counterpart, solid or medullary carcinoma. These tumors showed less frequent lymph node as well as hematogeneous metastases than pleomorphic carcinomas. In addition, they were usually diploid (84.6% versus 28.6%; P < 0.05) and lacked stabilization of the p53 protein (0% versus 42.9%; P < 0.05). No significant difference between the medullary and the pleomorphic tumor type was found with respect to bcl2 expression and the occurrence of Ki-ras mutations at codon 12. In contrast, microsatellite instability was almost totally restricted to poorly differentiated adenocarcinomas of the medullary type (100% versus 14.3%; P < 0.001). Finally, polymerase chain reaction revealed EBV DNA in 5 tumor specimens, which was, however, restricted to the peritumor lymphoid infiltrate as shown by in situ hybridization. Correlation with the biology of the tumors revealed that only one patient with the uniform cell type died due to metastastic disease during the follow-up period (median, 31 months), which was the case in five of the seven patients with the pleomorphic-type carcinoma (P < 0.025). Our results clearly indicate that the poorly differentiated colonic carcinoma with minimal or no glandular structures constitute two different entities, a medullary and a pleomorphic variant, which markedly differ in their phenotype, genotype, and prognosis.

[Endosonographic demonstration of extrapancreatic and extraintestinal gastrinoma]

HISTORY AND CLINICAL FINDINGS

No cause had been found for chronic diarrhoea in a 57-year-old man. Up to 15 watery stools daily had been without relation to food intake and without blood admixture. But muscular cramps had developed, especially in the legs. The patient had a history of recurrent peptic ulcers for which a selective proximal vagotomy had been performed 13 years ago. Physical examination was unremarkable.

INVESTIGATIONS

Alkaline phosphatase activity (182 U/l) and C-reactive protein (9.3 mg/l) were slightly raised; serum iron was 42 micrograms/dl, while all other routine laboratory tests, including protein electrophoresis, blood picture and differential count were within normal limits. Gastroscopy revealed ulcerative duodenitis, gastritis with erosions and numerous ulcers and reflux oesophagitis, grade III-IV. Endosonography showed enlarged gastric mucosal relief as sign of foveolar hyperplasia and a ca. 4 x 3 cm tumour next to the duodenal bulb. Gastrin level was 7537 pg/ml (normal < 150 pg/ml). Computed tomography and somatostatin receptor scintigraphy confirmed the site and size of the gastrinoma.

TREATMENT AND COURSE

Treatment with omeprazole (40 mg three times daily) slightly improved the symptoms. The tumour was excised a week after diagnosis. The patient has been symptom-free since then.

CONCLUSION

Chronic diarrhoea of unknown aetiology can be caused by an endocrine tumour; endosonography can often provide information on the diagnosis and location of such a tumour.

[Microsatellite instability--a new aspects in genetics and molecular biology of hereditary nonpolyposis and sporadic colorectal tumors]

Microsatellite instability (or replication error phenotyp) is a new molecular phenotyp of a substantial fraction of human cancers. The microsatellite instability in these cancers arises from alterations in normal regions of the genome consisting short sequences of repeated DNA. Ubiquitous changes in length of microsatellite sequences between constitutional and tumor DNA occur in about 90% of cases of HNPCC and in about 15% of cases of non-familial, sporadic colorectal cancer. Microsatellite instability is also found in a substantial percentage of sporadic endometrial, and gastric cancer, as well as in additional sporadic cancers, such as lung cancer which is usually not associated with HNPCC. Thus far, four different mismatch repair genes (hPMS1, hPMS2, hMLH1 hMSH2), all homologous to bacterial DNA repair genes have been identified as involved in HNPCC kindreds, and consequently they are associated with microsatellite instability. In conclusion, these basic genetic informations provide new insights into a new molecular pathway in oncogenesis, i.e. the occurrence of mutations in genomic stability genes leading to an increased cellular mutation rate (replication error phenotyp) and thus to cancer.

[Argon laser therapy of multiple eccrine cysts of sweat gland efferent ducts (eccrine hidrocystomas)]

BACKGROUND

Eccrine hidrocystomas are usually benign, solitary cystic tumors which are mainly treated by surgical measures. Treatment of the rare multiple lesions gets into difficulties because of complications.

PATIENT AND METHODS

A 74-year-old woman showed multiple bilateral lesions on the eyelids. Histology revealed eccrine hidrocystomas. The lesions were treated by Argon laser. Laser parameters were as follows: 600-1000 microns spot size, 500-600 mW power, 0.1-0.2 s time.

RESULTS

After 6 months follow up no recurrence of any of the tumors was observed.

CONCLUSION

Argon laser proved to be successful to treat multiple eccrine hidrocystomas.

[Miliary tuberculosis and silicosis with predominantly cerebral symptoms]

HISTORY AND CLINICAL FINDINGS

About 10 weeks before admission to hospital a 73-year-old woman developed a fever of up to 40 degrees C for three days. She then had subfebrile temperature for several weeks with some rises to 39 degrees C. She was known to have type II a diabetes mellitus and pulmonary silicosis, having worked in a porcelain and ceramic factory for many years. Before admission her cerebral functions were rapidly deteriorating, especially short-term memory. This was followed by increasing paraplegia of the legs with inability to walk. She finally had urinary and faecal incontinence and swallowing difficulties with tendency to aspiration, which necessitated hospitalisation.

INVESTIGATIONS

Both lactate dehydrogenase (339 U/l) and C-reactive protein (112 mg/l) were elevated; the platelet count was low (73000/microliters). Cerebrospinal fluid was unremarkable, as was computed tomography of the skull. But magnetic resonance imaging revealed multiple spotty lesions with low contrast-medium uptake throughout the brain, pointing to a disseminated bacterial or mycotic infection. 3 days later the chest-ray showed small nodular soft shadows in the lungs, and lung functions had decreased. Mycobacteria were found in the urine and liver biopsy showed granulomatous hepatitis, establishing the diagnosis of miliary tuberculosis in the presence of silicosis.

TREATMENT AND COURSE

Tuberculostatic treatment was instituted with four drugs (pyrazinamide, ethambutol, isoniazid and streptomycin. After 6 weeks the patient was again able to walk and continent of urine during the day. All cerebral functions gradually improved.

CONCLUSION

Miliary tuberculosis should be included in the differential diagnosis of ill-defined feverish disease, especially in the elderly.

Genomic instability in colorectal carcinomas: comparison of different evaluation methods and their biological significance

In order to demonstrate the relationship between microsatellite instability and other types of genomic instability, a series of 56 sporadic colorectal carcinomas was investigated by flow cytometrical ploidy analysis, oligonucleotide fingerprinting, and microsatellite polymerase chain reaction (PCR). Stabilization of the p53 gene product was analysed by immunohistochemistry and proliferative activity was determined flow cytometrically and by silver staining of nucleolar organizer regions (AgNORs). Of the 56 carcinomas, 11 (19 per cent) exhibited microsatellite instability; 33 of the cases were aneuploid (59 per cent) and 29 (52 per cent) showed alterations of the oligonucleotide fingerprints. There was a significant correlation of microsatellite instability with localization of these tumours proximal to the splenic flexure, diploid DNA content, and less frequent p53 stabilization. A solid growth pattern, mucinous differentiation, and a Crohn's-like lymphoid infiltrate were also characteristic for those tumours. The results demonstrate for the first time a significantly lower proliferative activity in tumours with microsatellite instability. Data obtained from DNA flow cytometry or from oligonucleotide fingerprinting did not correlate with such tumour characteristics. It is proposed that the use of microsatellite PCR facilitates specifically the detection of a group of colorectal cancers which may differ in pathogenesis and perhaps prognosis.

Expression of proliferating cell nuclear antigen (PCNA) and Ki-67 in dysplasia in inflammatory bowel disease

OBJECTIVE

Previous studies have revealed large variations in the interobserver agreement of dysplasia grading in inflammatory bowel disease. Therefore, we investigated the diagnostic value of two novel monoclonal antibodies (MIB 1 against Ki-67 and PC 10 against PCNA) in the detection of dysplasia.

METHODS

A total of 62 biopsies were investigated and histologically classified as follows: 13 probably positive for dysplasia; 15 low-grade dysplasia; five high-grade dysplasia; and 15 inflammation without dysplasia and 14 normal controls. The percentage of positive Ki-67- or PCNA-stained nuclei (= labelling index) was determined in relation to the distribution throughout the mucosa.

RESULTS

In all biopsies PCNA-labelling index exceeded that of Ki-67-labelling index. In the superficial half of the crypt PCNA- and Ki-67-labelling indices in the biopsies with 'indefinite for dysplasia, probably positive' or low-grade dysplasia exceeded that of normal tissue (P < 0.001). However, an unequivocal discrimination between biopsies with 'indefinite for dysplasia, probably positive' or low-grade dysplasia and inflammation was not possible. PCNA- and Ki-67-labelling indices were significantly higher in high-grade than in low-grade dysplasia (PCNA 81.4% vs. 44.3%, Ki-67 54.8% vs 30.9%, P < 0.001). Most interestingly, labelling indices of both markers were significantly (P < 0.0001) higher in biopsies with high-grade dysplasia than with active inflammation in the superficial half of the crypt.

CONCLUSION

PCNA and Ki-67 are useful adjuncts in the diagnosis of high-grade dysplasia, because high-grade dysplasia can easily be distinguished from low-grade dysplasia or active inflammation if the distribution of the positive-stained cells within the mucosa is taken into account. Lower unspecific binding and lower influence on proliferation activity by inflammation prompts us to prefer Ki-67 (MIB 1).

Prognostic significance of molecular biological and immunohistological parameters in gastrointestinal carcinomas

Histological type, malignancy grade, and tumor stage are among the most important parameters predicting outcome in cancer patients. Making use of immunocytochemistry as well as polymerase chain reaction-based techniques the demonstration of micrometastatic tumor spread, for example, into bone marrow, lymph nodes, and peritoneal cavity, is a new staging parameter of prognostic significance. In contrast, the prognostic value of different proliferation markers such as Ki67 (Mib 1), PCNA, and AgNOR has not yet been unequivocally established. A series of genetic change has been described in the development of cancer. In general, these changes seem to be of predictive value within defined tumor stages and it might be helpful to determine several genetic lesions within one tumor. Very recently a new mechanism of carcinogenesis closely related to the hereditary nonpolyposis cancer syndrome (HNPCC) was detected. Due to mutations in mismatch repair genes (hMSH 2, hMLH1, hPMS1,2) instabilities in simple repetitive genomic sequences occur, which are the genetic hallmark of most HNPCC tumors. This opens a new field to cancer prevention.

Comparative genomic in situ hybridization of colon carcinomas with replication error

The aim of the present study was to detect complex genetic alterations in colorectal carcinomas with and without microsatellite instability (MIN) by comparative genomic in situ hybridization. MIN due to replication errors is the hallmark of hereditary nonpolyposis colon cancer. None of 6 MIN-positive tumors showed amplifications, and only 2 tumors displayed deletions of one chromosomal segment each. In contrast, different gains and losses were observed in 11 of 12 MIN-negative carcinomas. The most frequent gains affected chromosomes 7, 13, and 20q, whereas deletions were observed on chromosomes 17, 18, and 9p. These results demonstrate different mechanisms of genetic instability in subgroups of colorectal carcinomas and may, therefore, support the hypothesis of different etiologies in tumors with and without MIN.

Sequential appearance and ultrastructure of amphophilic cell foci, adenomas, and carcinomas in the liver of male and female rats treated with dehydroepiandrosterone

Dehydroepiandrosterone (DHEA), a hormone of the adrenal cortex, acts as a peroxisome proliferator and hepatocarcinogen in rats upon long-term treatment with high doses in the diet. The aim of the present study was to identify the site of origin of hepatocellular neoplasms and the sequence of preneoplastic lesions. Twenty-five female and 25 male rats were given 0.6% DHEA in the diet; 25 animals of each sex were controls. Groups of 5 treated and untreated animals were sacrificed after 4, 20, 32, 70, and 84 wk. Amphophilic cell foci were detected after 32 wk of treatment; they developed from the liver parenchyma almost exclusively in the vicinity of portal tracts. Adenomas of the amphophilic or amphophilic/tigroid cell phenotype were observed at 70 wk of treatment. Highly differentiated hepatocellular carcinomas presenting a similar cellular phenotype occurred after 70-84 wk. The incidence of hepatocellular carcinomas was 44% in female and 11% in male rats. Ultrastructural studies of the amphophilic cell foci and tumors revealed a marked proliferation of mitochondria and a moderate proliferation of peroxisomes in all lesions. In addition, a very strong peroxisome proliferation was observed in perivenular hepatocytes in the liver of female rats. Peroxisomes usually lacked core and showed flocculent matrices. In male rats, weak peroxisomal proliferation was observed. Typical morphological abnormalities of these peroxisomes were paracrystalline inclusions of striated appearance. Although the most prominent peroxisome proliferation was observed in perivenular hepatocytes, these cells did not seem to be involved in tumor development. In contrast, the morphological similarity of the amphophilic cell foci and the amphophilic/tigroid cell adenomas and carcinomas, their coincident localization near portal tracts, and the sequential appearance of these lesions suggest that the amphophilic cell foci represent an early stage in DHEA-induced hepatocellular neoplasia. Mitochondrial proliferation as the most prominent feature in all stages of this model of hepatocarcinogenesis may offer a new approach for analysis of hepatocarcinogenesis induced by DHEA and possibly other peroxisomal proliferators.

Indirect gene diagnoses for complex (multifactorial) diseases--a review

The analysis of multifactorial diseases requires the efficient investigation of large numbers of (gene) loci and patient (family) samples. Since simple repetitive DNA markers are dispersed all over the chromosomes, molecular techniques employing these tools render most conventional screening procedures obsolete. Examples of tumors, autoimmune diseases and infections are presented to validate concepts of indirect gene diagnoses via simple, tandemly arranged, repetitive DNA sequences. The salient advantages of microsatellite technologies vs. those of multilocus DNA fingerprinting are weighed.

In vitro and ex vivo expression of nucleolar proteins B23 and p120 in benign and malignant epithelial lesions of the prostate

The expression of two specific nucleolar antigens, p120 and B23, has been investigated in the prostatic carcinoma cell line LNCaP as well as in 40 frozen and 40 formalin-fixed tissue samples of benign and malignant prostatic lesions (15 benign hyperplasias, 5 grade 1, 15 grade 2, and 5 grade 3 carcinomas). In vitro, immunoreactivity of p120 was confined to nucleoli of proliferating cells, with virtually no negative staining during S and G2/M phases. Unlike p120, B23 was expressed in the nucleoli of all LNCaP cells independently of growth and cell cycle phases. Hence, B23 was detectable in all stromal as well as in normal and malignant epithelial prostatic cells, both in fresh and in formalin-fixed tissue sections after microwave treatment. In contrast, the immunoreactivity of p120 was almost completely restricted to the nucleoli of prostate carcinoma cells: frozen sections of benign prostatic hyperplasia (n = 15) were either totally negative for p120 (n = 13) or had a low percentage of positively stained cells (labeling index = 3.3% in 3 cases). In the carcinoma group 76% (19/25) of the specimens were p120 positive, and there was a significant rise of labeling index from 18.1% in grade 1 to 82.2% in grade 3 carcinomas (P < 0.001). In contrast to B23, p120 could not be reliably demonstrated in formalin-fixed and paraffin-embedded tissue. We therefore conclude that anti-B23 is a general marker of nucleoli, whereas expression of p120 appears to correlate with "hyperactivity" of the nucleolus and provides a new tool for flow cytometrical and immunohistochemical assessment of nucleolar activity in tumor pathology.

Microsatellite instability: new aspects in the carcinogenesis of colorectal carcinoma

Very recently a new molecular mechanism in the tumorigenesis of colorectal carcinoma has been described which is closely linked to hereditary non-polyposis colonic cancer (HNPCC). Ubiquitous changes in the length of simple repetitive DNA sequences between constitutional and tumour DNA occur in about 90% of cases of HNPCC and in about 15% of cases of non-familial, sporadic colorectal carcinoma. Such microsatellite instabilities have been shown to be the phenotypical marker of mutations in the human homologues of prokaryotic mismatch repair genes (MutS, MutL, MutH). These data provide crucial new tools in the detection of patients at high risk of developing colon cancer and other HNPCC-related carcinomas. In addition, these developments provide new insights into a new, presumably primary event in oncogenesis, i.e. the occurrence of mutations in genomic stability genes leading to an increased cellular mutation rate ("mutator phenotype") and thus to cancer.

Detection of microsatellite instability in human colorectal carcinomas using a non-radioactive PCR-based screening technique

The aim of the present study was to establish a rapid, non-radioactive screening method for the detection of microsatellite instability (MIN). MIN is the primary characteristic of the mutator phenotype in tumours constituting hereditary non-polyposis colon cancers (HNPCC). We investigated 30 patients suffering from colorectal cancer using a non-radioactive PCR-based technique. MIN was present in 7 of 30 (23%) of the cases. There was a statistically significant correlation between MIN and localization of the tumour. Five of 7 (72%) tumours with MIN but only 4 of 23 (17%) tumours without MIN were localized in the proximal colon (P < 0.01). There was a tendency to higher MIN frequency in tumours of patients with familial clustering of cancers. However, this was statistically not significant (P > 0.05). In addition, no correlation between MIN and tumour grade and stage was found. For the investigations in the present study we used a non-radioactive PCR-based method followed by denaturating polyacrylamide gel electrophoresis and silver staining. This method is highly sensitive and reproducible. Thus, PCR-based analysis using a non-radioactive staining technique represents a comprehensive tool for MIN screening in diagnostic pathology.

Social isolation modifies the response of mice to experimental Mengo virus infection

To investigate the effects of social isolation on host resistance male mice were housed either individually (IH) or in groups of four or five (GH). All animals were infected with MengoM,L virus. Incubation time (INCUB), duration of illness (ILL), death rate (DR), histopathological changes, and serum corticosterone levels (CORT) were recorded. First, the effect of IH starting 4 days prior to infection was studied in 5 different inbred strains. Next, the effect of different IH length was examined, and the role of T-cells was investigated by comparing euthymic (+/+) and athymic (nu/nu) NMRI mice. Finally, the effects of the infection on CORT in IH and GH mice were compared in C57BL/6 mice. The major findings were: 1. IH significantly increased ILL in all but the DBA/2 strain, whereas DR was not affected except in C57BL/6. 2. Longer IH (starting 35 [DBA/2] or 10 [NMRI] days prior to virus inoculation) significantly shortened INCUB and prolonged ILL, but IH starting on the day of virus inoculation [DBA/2] significantly prolonged INCUB and shortened ILL. 3. NMRI nude mice exhibited an unaltered DR accompanied by a tremendously prolonged INCUB. 4. Investigations in C57BL/6 mice revealed a significant rise of CORT after infection. This increase was higher in IH compared to GH mice. It is suggested that IH attenuates T-cell mediated inflammatory processes and/or increases macrophage activation, which in turn results in a prolonged course of the disease.

[In vivo and ex vivo expression of nucleolar proliferation-associated antigens (p120, B23) in the prostate]

Expression of two nucleolar antigens, p120 and B23, was studied in a prostatic carcinoma cell line (LNCaP) and in frozen and paraffin embedded tissue sections of 40 benign and malignant prostatic lesions. The percentage of p120 negative G0/G1 phase cells rose significantly during transition from exponential to plateau growth phase in vitro (from 9% to 32%). In contrast, B23 was equally expressed throughout different cell cycle and growth phases. Thus, nucleoli of almost all stromal and epithelial cells were stained by B23 in tissue sections. P120, however, selectively stained nucleoli of proliferating prostatic epithelium. Whereas 88% (13/15) of benign hyperplasia were p120 negative this was the case in only 24% (6/25) of carcinomas. Using microwave procedure both MoAbs reacted in paraffin sections, but the percentage of p120 negative cases doubled. A routine application to formalin fixed and paraffin embedded tissue cannot be recommended thus far.

Diagnosis of transfusion-associated graft-versus-host disease by genetic fingerprinting and polymerase chain reaction

A patient with Hodgkin's disease (clinical stage IIIB) received chemotherapy and total nodal irradiation. After the transfusion of filtered packed red cells, this patient developed transfusion-associated graft-versus-host disease (TA-GVHD). The genetic fingerprint of the patient's peripheral blood lymphocytes (PBLs) differed completely from that of her other body tissues. Normally, after transfusion, only the patient's own genetic fingerprints are observed in the PBLs, as exemplified in more than 10 control cases in which the transfused blood had not been filtered before transfusion. No signal bands corresponding to those of the blood donor could be demonstrated in samples of the patient's tissue DNA. Moreover, chimerism was detected in the hybridization pattern of the patient's PBLs on the ninth day after the onset of symptoms. Polymorphic simple repeats in the HLA-DRB gene after amplification by polymerase chain reaction were also investigated, which confirmed the fingerprinting results. The advantages of these methods for the diagnosis of TA-GVHD include the rapid and unequivocal diagnosis as well as the fact that there is no need for the relatives to be HLA typed.

[The effect of low-dose heparin therapy on patients in an internal medicine intensive care unit]

It is reported on 191 patients of an intensive care unit, in whom for the purpose of the prophylaxis of thromboses and thromboembolic complications a low-dose heparinisation was carried out. For comparison served the documents of 137 patients who were admitted to the same department for homogeneous reasons but had not been treated prophylactically with anticoagulants. In no case more massive haemorrhages developed which might have compelled us to interrupt the therapy. In spite of the low-dose heparinisation 4 pulmonary embolisms as well as thromboses of the abdominal aorta, the radial artery and the coronary arteries were the result; they were confirmed autoptically . Thus the low dose heparinisation does not represent a sufficient protection against the thromboembolic complications for patients with internal diseases who are confined to bed. The demand is made to establish the individual need of heparin and to adjust the heparin dose according to this.