Isolation of rat embryonic stem-like cells: a tool for stem cell research and drug discovery.

The establishment of rat embryonic stem cells constitutes a precious tool since rat has been extensively used in biomedical research, in particular for the generation of human neurodisease animal models. Up to now only a few studies have described the isolation of rat embryonic stem-like cells. One out of 9 isolated rat embryonic stem-like cell lines (B1-RESC) obtained from a 4.5-day post-coitum blastocyst were extensively characterized and kept in culture for up to 80 passages on feeders with LIF. The stable growth of these cells and the expression of pluripotent markers were confirmed up to a high number of passages in culture, also in the absence of feeders and LIF. B1-RESC expresses the three germ layers markers both in vitro, within differentiating embryoid bodies, and in vivo through teratoma formation. Collectively, the B1-RESC line with a stable near-diploid karyotype can be used as a highly sensitive tool for testing anti-proliferative molecules.

Immunohistochemical expression of p16(INK4A) protein in oral lichen planus.

The expression of p16(INK4A) has been investigated in oral leukoplakias (OLK), but no data are available about oral lichen planus (OLP). In this study, p16(INK4A) immunohistochemical expression was evaluated in 56 OLP and 36 OLK (12 without inflammation [NI-OLK] and 24 with chronic inflammation [I-OLK]) and compared with 23 reactive nonspecific inflammations (INF) and 14 normal control samples. The p16(INK4A) immunostaining was considered to be positive when >5% of keratinocytes were stained. All normal control samples were negative. Positive p16(INK4A) was detected in OLP, IOLK, and INF. Significant differences in p16(INK4A) positivity were found between OLP (64%) and OLK (28%) (χ(2) = 17.7; P < .01), and between I-OLK and NI-OLK (χ(2) = 4.5; P < .05). No significant difference was found between OLP and INF (43%). In conclusion, positive p16(INK4A) in OLP patients seems to be related to reactive inflammatory processes rather than to a risk of progression to oral squamous cell carcinoma.

Fast track biopsy method: a rapid approach to preoperative diagnoses.

INTRODUCTION: It is well known that the use of a microwave oven greatly reduces the time for histoprocessing. OBJECTIVE: Apply the microwave-based histoprocessing method "Fast Track Biopsy" (FTB), previously described for breast needle-core biopsies, to samples of other organs. METHODS: From 01/09/2008 to 31/12/2008, 125 normal and neoplastic tissue samples (thickness from 0.2 and 1.2 cm) were collected, processed according to the FTB technique, stained with haematoxylin/eosin (H/E) and analysed with tissue-specific immunohistochemical (IHC) markers. RESULTS: The quality of both H/E and IHC stained sections was comparable to that obtained with standard methods. Sample thickness less than 0.5 cm gave better results. DISCUSSION: the FTB method is suitable for most tissue types, and is thus useful for preoperatory diagnoses.

Prognostic value of Ki67 from clinically and histologically 'normal' distant mucosa in patients surgically treated for oral squamous cell carcinoma: a prospective study.

The frequent spread of oral squamous cell carcinoma (OSCC) has been explained by the persistence of genetically altered mucosa after surgery. This study examined whether clinically and histologically 'normal' mucosa distant from the primary tumour (from the opposite cheek) has an abnormal proliferative status, and whether this is associated with poor prognosis in terms of local recurrence or lymph node metastasis. The prospective study included 47 consecutive patients with OSCC. Disease-free survival endpoints were defined as the duration between surgical resection and the diagnosis of recurrence, lymph node metastasis, death or last follow-up. Proliferative status was evaluated by Ki67 expression. The mean Ki67 value (16.5+/-8.9) in the distant mucosa was statistically higher than that in controls (8.8+/-2.9). Abnormally high Ki67 values (>20%) were detected in 11 OSCC patients (23%). Multivariate analysis showed that Ki67 value in distant mucosa was a powerful independent prognostic factor, greater than tumour differentiation or clinical stage for the disease-free survival rate; it was statistically negative regarding local recurrence. Some patients surgically treated for OSCC have an abnormal proliferative status in areas distant from the primary tumour. The Ki67 value in these areas is a promising prognostic factor.

[Choroid plexus tumours: cytogenetic analysis of a single case and literature review]. / Papilloma dei plessi corioidei: analisi citogenetica di un caso e revisione della letteratura.

Choroid plexus tumours are intraventricular papillary lesions that are observed in typical papillomas, atypical papillomas and carcinomas. They usually occur in childhood, and can result in hydrocephalus and increased intracranial pressure. The present paper describes a case of choroid plexus papilloma in an adult woman; cytogenetic analysis of the lesion is also presented, which demonstrated the presence of tumour mosaicism. Compared to the chromosomal aberrations observed in previous cases, those in the present tumour do not show significant differences between papillomas harboured in adults and paediatric patients. Moreover, there was no apparent correlation between genetic alternations in typical and atypical papillomas and prognosis or recurrence.

High proliferative activity and chromosomal instability in oral lichen planus.

The study aimed to assess the proliferative activity and karyotype in Oral Lichen Planus (OLP) lesions. G-banding chromosomal analysis of short-term primary cultures, and immunohistochemical expression of Ki67 and p53 were applied in 30 consecutive OLP patients divided into two groups according to clinical presentation of the lesions, and in nine subjects as negative controls. Mean values of Ki67 and p53 expression differed significantly (P<.01) between controls and patients groups with reticular or atrophic-erosive forms of OLP, whereas there was no significant difference between the two groups of patients with reticular or atrophic-erosive lesions. Six OLP patients showed clonal chromosome alterations, four of them associated with p53 overexpression. In conclusion, OLP is characterized by a high cellular turnover in most patients irrespective of clinical disease presentation. The genetic instability found in some patients should be interpreted as a consequence of the enhanced epithelial turnover, although we cannot rule out the possibility that some of the cytogenetic non-random anomalies observed represent early steps in cancer development.