Acute intraoperative heparin-induced thrombocytopenia (HIT) and thrombosis during coronary artery bypass grafting: Two case reports providing evidence for the role of preoperative LMWH in triggering sensitization.

INTRODUCTION: Systemic anticoagulation is necessary during cardiac surgery. To date, the only well established anticoagulation protocol involves the use of heparin. However, heparin can cause heparin-induced thrombocytopenia (HIT) a potentially life threatening immune-mediated thromboembolic syndrome. Until now, devastating consequences of HIT syndrome in patients undergoing heart surgery have been described, but only postoperatively. Here we report the development of HIT syndrome during cardiac revascularization by intra-operative heparin administration in two patients previously exposed to LMWH. PATIENTS/METHODS: We report on two patients who developed rapid and profound intravascular coagulation with severe thrombocytopenia (platelet count decreased from ≥250×109/L to 50×109/L) due to HIT development caused by heparin administration during coronary artery bypass graft surgery. In addition we report that fondaparinux, given intra-operatively in association with antithrombin, may be a suitable alternative anticoagulant for successfully preventing the devastating consequences of intra-operative HIT development. CONCLUSION: To our knowledge, this is the first report describing the development of acute intra-operative HIT, secondary to high-dose UFH administered for coronary revascularization, in which the unexpected presence of platelet-activating anti-PF4/heparin antibodies at surgery was explained by preoperative administration of a one-week course of LMWH but without any preoperative evidence for HIT.

Differential telomerase expression in idiopathic pulmonary fibrosis and non-small cell lung cancer.

Telomerase is a reverse transcriptase ribonucleo-protein (h-TERT) that synthesizes telomeric repeats using its RNA component (h-TERC) as a template. Telomerase dysfunction has been associated with both fibrogenesis and carcinogenesis. In this study, we aimed to evaluate the telomerase mRNA expression levels of both subunits (h-TERT and h-TERC) in lung tissue and bronchoalveolar lavage fluid (BALF) from patients with idiopathic pulmonary fibrosis (IPF) and non-small cell lung cancer (NSCLC), since there are indications of common pathogenetic pathways in these diseases. We prospectively examined lung tissue samples from 29 patients with IPF, 10 patients with NSCLC and 21 controls. Furthermore, we examined BALF samples from 31 patients with NSCLC, 23 patients with IPF and 12 control subjects. The mRNA expression for both h-TERT and h-TERC was measured by real-time RT-PCR. In the lung tissue samples, both h-TERT and h-TERC mRNA expression levels varied among the 3 groups (p=0.036 and p=0.002, respectively). h-TERT mRNA levels in the patients with IPF were lower compared with those in the controls (p=0.009) and patients with NSCLC (p=0.004). h-TERC mRNA levels in the patients with IPF were lower compared with those in the controls (p=0.0005) and patients with NSCLC (p=0.0004). In the BALF samples, h-TERT mRNA expression levels varied among the groups (p=0.012). More specifically, h-TERT mRNA levels in the patients with IPF were higher compared with those in the controls (p=0.03) and patients with NSCLC (p=0.007). The attenuation of telomerase gene expression in IPF in comparison to lung cancer suggests a differential role of this regulatory gene in fibrogenesis and carcinogenesis. Further functional studies are required in order to further elucidate the role of telomerase in these devastating diseases.

mRNA expression of G(1)-phase cell cycle regulatory molecules in bladder cancer.

PURPOSE: Cell cycle regulation, which is important for normal cellular proliferation, is controlled by a complex network of intracellular proteins, with cyclins, cyclin-dependent kinases (CDKs) and cyclin-dependent kinase inhibitors (CD-KIs) playing a central role. This equilibrium is interrupted in cancer cells, resulting in uncontrolled cellular proliferation. METHODS: In the present study we examined, by means of semi-quantitative RT-PCR, the expression of G(1)-phase cell cycle regulators MDM2, E2F1, Cyclin D1 (CCND1), CDK4, p19(INK4D), p21(WAF1/CIP1) and p27(KIP1) in a series of 32 bladder cancer specimens paired with adjacent normal tissues. RESULTS: Cyclin D1 was overexpressed in 10/32 (31.2%) and downregulated in 8/32 (25.0%) bladder cancer specimens. Additionally, p21 was overexpressed in 9/32 (28.1%) and downregulated in 10/32 (31.3%) cancer samples. On the contrary, MDM2, E2F1, CDK4, p19 and p27 expression was normal in the majority of malignant specimens. Further statistical analysis revealed significant associations between increased p21 levels and bladder cancer patients with no exposure to chemicals (p=0.048), as well as with patients with no artificial sweetener intake (p=0.012), and between increased Cyclin D1 levels and study subjects with no artificial sweetener intake (p=0.012). CONCLUSION: Based on these results, we conclude that Cyclin D1 and p21 mRNA deregulation seems to be an important event in bladder carcinogenesis. However, further studies are needed, in order to determine whether these two cell cycle regulators can be used as markers for the early detection of bladder cancer and to monitor its progression and recurrence.

Genomic instability, mutations and expression analysis of the tumour suppressor genes p14(ARF), p15(INK4b), p16(INK4a) and p53 in actinic keratosis.

Actinic keratosis (AK) is a well-established pre-cancerous skin lesion that has the potential to progress to squamous cell carcinoma (SCC). We investigated the involvement of the CDKN2A, CDKN2B and p53 genes in AK and in the progression of AK to SCC. Mutational analysis on exons 1a, 1b and 2 of the CDKN2A locus and exon 1 of the CDKN2B locus as well as allelic imbalance was performed in 26 AK specimens. Expression levels of the genes p14(ARF), p15(INK4b), p16(INK4a) and p53 were examined in 16 AKs and 12 SCCs by real-time RT-PCR. A previously described polymorphism of p16(INK4a) (Ala148Thr) was detected at an allelic frequency of 12%. Six samples carried novel mutations at codon 71 of the CDKN2A locus and one sample presented an additional mutation at codon 65. Two AK samples carried a not-previously described non-UV type missense mutation at codon 184 (Val184Glu) of exon 1b in the p14(ARF) gene. Regarding the CDKN2B locus a new mutation at codon 50 (Ala50Thr) and another at codon 24 (Arg24Arg), were detected. Microsatellite instability (MSI) was found in 15% of AKs in at least one marker, indicating that genetic instability has some implication in the development of AK. Down-regulation of p16(INK4a) and p53 mRNA levels was noted in SCC compared to AK. TSGs expression levels in sun-exposed morphologically normal-appearing skin, suggests that abnormal growth stimuli might exist in these tissues as well. Furthermore, we suggest a possible role of p15(INK4b), independently from the intracellular pathway mediated by p16(INK4a), and of p14(ARF) in AK development, as well as in the progression of AK to SCC. The deregulation of the expression profiles of the CDKN2A, CDKN2B and p53 genes may, independently of mutations and LOH at 9p21, play a significant role in AK and progression of AK to SCC.

Transcriptional inactivation of p53, Bax, Bcl-2 and Mdm2 correlates with malignant transformation of the uterine cervix.

Deregulation of the apoptotic machinery plays a major role in cell death, cellular transformation and cancer. p53, Bcl-2, Bcl-XL, Bax and Mdm2 mRNA expression patterns were evaluated in tissue samples with cervical intraepithelial neoplasia (CIN) and cervical cancer compared to those of normal cervical tissues, and correlated with the underlying cervical lesions. Transcript levels of the above genes were assessed by RT-PCR analysis in a total of 44 cervical specimens. p53, Bcl-2, Bax and Mdm2 transcript levels were significantly different in the normal, CIN and cancer specimen groups (p=0.003, p=0.009, p=0.040 and p=0.001, respectively). Specifically, p53, Bax and Bcl-2 exhibited substantially lower transcript levels in CIN lesions compared to controls, whereas Bax mRNA levels showed a significant decrease in cancer compared to normal specimens. Mdm2 mRNA expression was considerably lower in cancer than in CIN lesions or normal cervix. High-grade squamous intraepithelial lesions exhibited lower p53 and Bcl-2 mRNA levels than controls (p=0.002, p=0.016). Coexpression analysis revealed more correlations between the above apoptosis-related molecules in normal tissues compared to CIN or cancer specimens. p53 showed significant coexpression with Bax, Bcl-2 and Mdm2 (p=0.040, p=0.013 and p=0.015, respectively) in normal cervical specimens. Bax and Bcl-XL mRNA expression was negatively correlated. Mdm2 transcriptional levels correlated significantly with those of Bax, Bcl-XL and Bcl-2. Our findings show that p53, Bax, Bcl-2 and Mdm2 mRNA expression levels correlate with the malignant transformation of the uterine cervix. mRNA coexpression patterns of the members of the pro- and anti-apoptotic family examined in cervical carcinogenesis were found to be disrupted in CIN and cancer, as already demonstrated at the protein level.

Transcriptional inactivation of p53, Bax, Bcl-2 and Mdm2 correlates with malignant transformation of the uterine cervix.

Deregulation of the apoptotic machinery plays a major role in cell death, cellular transformation and cancer. p53, Bcl-2, Bcl-XL, Bax and Mdm2 mRNA expression patterns were evaluated in tissue samples with cervical intraepithelial neoplasia (CIN) and cervical cancer compared to those of normal cervical tissues, and correlated with the underlying cervical lesions. Transcript levels of the above genes were assessed by RT-PCR analysis in a total of 44 cervical specimens. p53, Bcl-2, Bax and Mdm2 transcript levels were significantly different in the normal, CIN and cancer specimen groups (p=0.003, p=0.009, p=0.040 and p=0.001, respectively). Specifically, p53, Bax and Bcl-2 exhibited substantially lower transcript levels in CIN lesions compared to controls, whereas Bax mRNA levels showed a significant decrease in cancer compared to normal specimens. Mdm2 mRNA expression was considerably lower in cancer than in CIN lesions or normal cervix. High-grade squamous intraepithelial lesions exhibited lower p53 and Bcl-2 mRNA levels than controls (p=0.002, p=0.016). Coexpression analysis revealed more correlations between the above apoptosis-related molecules in normal tissues compared to CIN or cancer specimens. p53 showed significant coexpression with Bax, Bcl-2 and Mdm2 (p=0.040, p=0.013 and p=0.015, respectively) in normal cervical specimens. Bax and Bcl-XL mRNA expression was negatively correlated. Mdm2 transcriptional levels correlated significantly with those of Bax, Bcl-XL and Bcl-2. Our findings show that p53, Bax, Bcl-2 and Mdm2 mRNA expression levels correlate with the malignant transformation of the uterine cervix. mRNA coexpression patterns of the members of the pro- and anti-apoptotic family examined in cervical carcinogenesis were found to be disrupted in CIN and cancer, as already demonstrated at the protein level. (Int J Biol Markers 2005; 20: 18-27).

Association between schizophrenia and DRD3 or HTR2 receptor gene variants.

Schizophrenia is a severe and common psychiatric disorder afflicting 1% of the world population. A role of many neurotransmitter receptors in schizophrenia was suggested by an association with several polymorphisms located in their coding regions. In this study we examined the contribution of the T-102C and A-206G transitions in the 5-HTR2a and DRD3 receptor genes respectively to genetic susceptibility and phenotypic expression of schizophrenia disorder within the Greek population. We determined by PCR and RFLP analysis the genotype for the above polymorphisms in 114 schizophrenic hospitalized individuals and 192 control samples. In contrast to previous reports from large European multicentre studies, which indicate significant correlation between schizophrenia and C-102 allele of the T-102C polymorphism, in this study we observed a statistically significant overall association between the disorder and allele T-102 (P<0.0001, odds ratio (OR)=2.11, 95% CI=1.48-3.02). We also found a highly significant excess of the T-102/C-102 and C-102/C-102 genotypes in the normal group (P<0.001). Comparison of the patients with the controls for the DRD3 polymorphism (A-206G transition) showed marginally nonsignificant differences in the genotypic (P=0.054) and no significance in the allelic (P=0.163) frequencies. However, the A-206/A-206 genotype seems to positively contribute to the disorder appearance, when compared to A-206/G-206 as genotype base line risk (P=0.016, OR=1.88, 95% CI=1.09-3.26). In conclusion, from genetic association analysis of this schizophrenic population, a significant association is clearly determined between the HTR2 genetic polymorphism and the presence of schizophrenic disorder, manifested as increased risk of schizophrenia for carriers of the T-102 allele.