Mutation and expression of the p53 tumor suppressor gene in tumor samples and cancer cell-lines - comparison of nonisotopic direct DNA-sequencing, immunoblotting and immunohistochemistry.

Mutations in the nuclear phosphoprotein p53 are the most frequent genetic alterations in human solid tumors detected so far. These mutations are clustered in highly conserved domains spanning from exon 4 to 9 of the gene. A very precise method of detecting p53 mutations is to sequence these domains. However, 2 to 3 overlapping PCR-amplifications were needed to span the whole mutation-prone region. We used a very rapid non radioactive solid-phase DNA sequencing method starting from mRNA to sequence the p53 domains in both directions with T7 DNA-polymerase allowing detection of the heterozygous state, where one allele shows the wild-type sequence, the other a mutated one. First we sequenced four colon carcinoma cell lines with known p53 mutations and one T-cell-leukemia cell line with a heterozygous situation to validate our method. Using this method we sequenced the p53 gene (exons four to nine) from 16 primary colon carcinomas. Seven of these 16 (44%) carcinomas showed mutations in the p53 gene resulting in amino acid exchanges. One showed a silent mutation, another one showed two point mutations in the highly conserved domain of the p53 gene. These colorectal carcinomas have been examined for overexpression of the p53 protein using a panel of monoclonal antibodies directed against p53 (PAb1801, PAb240, PAb421, PAb1620) by immunohistochemical analysis and immunoblotting. Furthermore, four colorectal cancer cell lines were examined by indirect immunofluorescence technique with the same mAb PAb1801 as used in histological staining. Analysis of 6 out of 15 (40%) tumor specimens revealed markedly positive p53 nuclear staining patterns using monoclonal antibody PAb1801. These data suggest that there is quite a good correlation between point mutation of the p53 gene and nuclear staining with monoclonal antibody PAb1801 detecting overexpressed p53 protein. Moreover, there is no convincing evidence that wild-type protein can be detected using the monoclonal antibodies PAb 1801 and PAb 1620.

Testicular sex cord stromal tumour with granulosa cell differentiation: detection of steroid hormone receptors as a possible basis for tumour development and therapeutic management.

A testicular sex cord stromal tumour with granulosa cell differentiation, typical of granulosa cell tumours of the adult type, was investigated immunohistologically on snap frozen and paraffin wax embedded material. The predominance of vimentin and the additional expression of cytokeratin subtypes 8 and 18, as well as the negative staining for epithelial membrane antigen, accorded with results previously reported, for ovarian granulosa cell tumours; the lack of expression of desmoplakin, however, was a distinctive feature. Together with negative staining for leucocyte common antigen, the antigen pattern facilitates the differential diagnosis between granulosa cell tumour and undifferentiated carcinoma or gonadal lymphoma, although its suitability for differentiating within the group of gonadal stromal tumours seems to be limited. The small growth fraction, shown by the monoclonal antibody Ki-67, is typical of the clinical behaviour of granulosa cell tumours. The expression of oestrogen and progesterone receptors, also recently found in testicular Leydig cell tumours, may provoke new approaches to the management of testicular granulosa cell tumours, as well as a new hypothesis on the development of these tumours.

[External validity of clinical trials for treatment of dementia with ginkgo biloba extracts]. / Die Rolle der externen Validität bei der Beurteilung klinischer Studien zur Demenzbehandlung mit Ginkgo-biloba-Extrakten.

OBJECTIVES: Ginkgo bilobaextracts have been applied in the treatment of dementia of vascular origin and Alzheimer disease for a long time. However, in the most elaborated systematic review to date, Birks and colleagues drew quite a moderate conclusion in spite of the overall positive results. The reason for such a moderate interpretation often lies in the preference of internal validity such as randomisation and blinding, sometimes at the expense of external validity (conditions of everyday practice). Because of this, we analysed the clinical trials evaluated by Birks et al. in the light of the following questions: 1) To what extent are criteria of external validity considered? 2) Does the additional evaluation of external validity lead to differences in the estimation of efficacy? 3) What are the results of our analysis in regard to the efficacy of ginkgo biloba extract? MATERIAL AND METHODS: The selection of the clinical trials was based upon those included in the review carried out by Birks et al. (2002). The criteria for evaluating external validity were developed by consulting physicians specialised in geriatrics, experts in herbal pharmaceutics and affected/ related individuals (patients and relatives). RESULTS: We analysed 34 placebo-controlled clinical trials with a total of 37 comparisons. 21 trials showed significant results in favour of the ginkgo application in more than 50% of investigated outcome parameters, eight were significant for less than 50% of the parameters, four showed a trend in favour of ginkgo, and only two studies (with 4 comparisons) found no advantage for ginkgo. One of these negative studies used daily doses far below the usual dose range [corrected] We found no evidence for publication bias. None of the studies considered all criteria of external validity. Out of the seven studies with relatively high external validity and good overall quality, five showed a significant result in more than 50% of parameters, two in < or = 50%. Severe adverse effects were not mentioned in the studies. DISCUSSION AND CONCLUSIONS: 1) In the clinical studies analysed external validity was taken into account only moderately, especially with respect to additional non-pharmaceutical interventions and selection of participants. 2) The evaluation according to external validity led to a different selection of studies that were used for estimation of the ginkgo efficacy without effects on the overall result. 3) Sufficient evidence of the efficacy of ginkgo bilobaextracts in the treatment of dementia of vascular origin and Alzheimer disease is provided in spite of methodological limitations. Further studies should focus on effectiveness, ginkgo-sensitive subgroups, more individualised therapeutic goals and corresponding outcome measurements.

Renal cell cancer and concomitant transitional cell cancer of the renal pelvis and ureter in the same kidney--report of 4 cases and review of the literature.

Three patients (1 man, 81 years old; 2 women, 56 and 61 years old) had renal cell cancer and transitional cell cancer in the same kidney, and another patient (female, 77 years old) had renal cell cancer and transitional cell cancer in the ipsilateral ureter. Simultaneous occurrence of renal cell cancer and transitional cell cancer is an extremely rare entity with only 15 cases having been reported.

Identification of different laminin binding proteins in basolateral cell membranes of human colorectal carcinomas and normal colonic mucosa.

The adhesive properties of tumour cells to laminin, the major glycoprotein of basement membranes, play a crucial part in the complex process of tumour invasion and metastasis. We therefore investigated the expression of laminin binding proteins in isolated basolateral cell membranes of human colorectal carcinomas and the adjacent normal colonic mucosa. Cell membrane binding assays and immunoblotting experiments showed appreciable quantitative and qualitative differences in the expression of these proteins in neoplastic and normal tissue. Epithelial basolateral cell membranes of colorectal carcinomas bound five to eight times more radioactive labelled laminin than basolateral cell membranes of the adjacent normal colonic epithelium. The expression of laminin binding proteins with Mr 66,000-69,000 daltons corresponding to the so called 'Mr 67,000 dalton laminin receptor' was three to four times higher in colorectal carcinomas than in normal colonic epithelium. In addition, laminin binding proteins with higher molecular weights, which may be related to the family of integrins, were also increased in colorectal carcinomas. In particular, laminin binding proteins with Mr 180,000 daltons were exclusively expressed on neoplastic epithelial cells of human colorectal carcinomas. Our data suggest that certain classes of laminin binding proteins may be selectively expressed on colonic tumour cells, leading to an increased capacity for migration, invasion, and metastasis.

Diminished expression of integrin adhesion molecules on human colonic epithelial cells during the benign to malign tumour transformation.

Integrins are transmembrane molecules that mediate cell-cell and cell-substratum adhesion. Because alterations in the adhesive properties of tumour cells are thought to influence tumour cell invasion, the expression of integrin alpha and beta chains in 19 human colorectal carcinomas, eight adenomas, and eight normal colon tissues was examined immunohistochemically using an indirect immunofluorescent technique. Normal colonic epithelial cells were found to express the integrin alpha 3, alpha 5, alpha 6, beta 1, and beta 4 chains, whereas the alpha 2 chain was expressed only on epithelial cells lining the base of the crypts and was absent from cells lining the mouth of the crypts or the surface epithelium. No epithelial staining of the alpha 1, alpha 4, beta 2, and beta 3 chains was observed. A progressive reduction of all normally expressed alpha and beta chains was associated with increasing neoplastic transformation. The expression of the alpha 3 and alpha 5 chains was already noticeably reduced in adenomas, and was completely absent in most colonic carcinomas. In contrast, alpha 6, beta 1, and beta 4 expression was maintained in adenomas, whereas the transformation from benign to malignant neoplasms associated with infiltrative growth was characterised by diminished or lost expression of alpha 6, beta 1, and beta 4 chains. Thus, the decreased expression of integrins in human colon carcinomas may contribute to the altered adhesion and migration properties of these tumour cells.

Neuron-specific enolase: a serum tumor marker in renal cell carcinoma?

In previous reports, neuron-specific enolase (NSE) has been considered to be a useful tumor marker in renal cell carcinoma (RCC). This led us to perform a prospective clinical trial in this field. NSE was checked as a tumor marker for diagnosis and monitoring of patients with RCC. We report on 55 patients and their NSE level before and after radical nephrectomy and correlated the serum level of NSE to immunohistological staining and clinical stage of nephrectomy specimens. In contrast to other researchers, our results on NSE as a tumor marker in RCC are disappointing.

Detection of viral DNA by in situ hybridization using bromodeoxyuridine-labeled DNA probes.

Detection of viral DNA in infected tissues is demonstrated by in situ nucleic acid hybridization employing bromodeoxyuridine (BrdUrd)-labeled probes. BrdUrd is used alternatively to biotinylated nucleotides in the preparation of DNA probes and, after hybridization, developed with a monoclonal anti-BrdUrd antibody and the alkaline phosphatase-anti-alkaline phosphatase technique. The sensitivity using both BrdUrd- and biotin-labeled probes is similar. Furthermore, the simultaneous detection of viral coinfections will be possible by means of this technique in conjunction with biotin-labeled DNA probes.

[Intra-orbital space occupying lesion. Differential diagnostic considerations based on a rare case]. / Intraorbitale Raumforderung. Differentialdiagnostische Uberlegungen anhand eines seltenen Falles.

The differential diagnosis of an intraorbital tumor is discussed on the basis of a rare case of cyst formation that presented clinically in the lacrimal duct. Rapid progression of exophthalmos and visual loss required an immediate surgical intervention. Using a medial orbitotomy, a cystic tumor was extirpated that had no connection to the paranasal sinuses. Postoperatively, the visual defect and exophthalmos resolved completely. This case demonstrates the problems of differential diagnosis within the orbit that require close interdisciplinary cooperation. The final diagnosis can often be made only after surgical exploration and histopathology of tissue specimens.

High-level sensitivity of quantitative pp65 cytomegalovirus (CMV) antigenemia assay for diagnosis of CMV disease in AIDS patients and follow-up.

Cytomegalovirus (CMV) antigenemia was evaluated in 174 patients positive for human immunodeficiency virus. Antigenemia could be detected in 96.7% of patients with CMV disease, 76.9% of patients suffering from a relapse of the disease, and 11.4% of asymptomatic patients with CD4 levels of < 100 cells per microliter. No antigenemia was detected in patients with CD4 levels of 250 to 500 cells per microliter. Specificity and the positive predictive value for CMV disease were increased only if more than 5 positive cells per slide were considered. However, CMV disease may also occur in patients with low-grade antigenemia.