Biochemical differentiation between cancerous and normal human colorectal tissues by micro-Raman spectroscopy.

Human colorectal tissues obtained by ten cancer patients have been examined by multiple micro-Raman spectroscopic measurements in the 500-3200 cm-1 range under 785 nm excitation. Distinct spectral profiles are recorded from different spots on the samples: a predominant 'typical' profile of colorectal tissue, as well as those from tissue topologies with high lipid, blood or collagen content. Principal component analysis identified several Raman bands of amino acids, proteins and lipids which allow the efficient discrimination of normal from cancer tissues, the first presenting plurality of Raman spectral profiles while the last showing off quite uniform spectroscopic characteristics. Tree-based machine learning experiment was further applied on all data as well as on filtered data keeping only those spectra which characterize the largely inseparable data clusters of 'typical' and 'collagen-rich' spectra. This purposive sampling evidences statistically the most significant spectroscopic features regarding the correct identification of cancer tissues and allows matching spectroscopic results with the biochemical changes induced in the malignant tissues.

Potentiation by caffeine of cytogenetic damage induced by steroidal derivatives in human lymphocytes in vitro.

We studied the effects of three newly synthesized steroidal derivatives of nitrogen mustards, alone or in combination with caffeine, on sister chromatid exchange (SCE) frequencies and on human lymphocyte proliferation kinetics. The agents have as alkylator functionalities either P-N,N-bis(2-chloroethyl)aminophenyl-buturate (CHL) or P-N,N-bis(2-chloroethyl)aminophenyl-acetate (PHE), esterified with a modified steroidal nucleus. An enhancement of SCE frequency was seen with compounds which contain either PHE or CHL as alkylators and are esterified with a steroidal nucleus having added a cholestene group in the 17-position of the D-ring. The exocyclic insertion of an -NHCO- group in the D-ring of the steroidal nucleus esterified with PHE (amide ester of PHE) gave a compound showing increased SCE frequency. Enhanced cytogenetic damage was observed when lymphocytes were exposed in vitro to caffeine. The compounds, alone or in combination with caffeine, caused a concentration-dependent increase in SCE frequencies and cell division delays, and caffeine was found to act synergistically with the steroidal alkylators.

Evaluation of the LIM homeobox genes LHX6 and LHX8 as candidates for Tourette syndrome.

The etiology and pathophysiology of Tourette Syndrome (TS) remain poorly understood. Multiple lines of evidence suggest that a complex genetic background and the cortico-striato-thalamo-cortical circuit are involved. The role of Lhx6 and Lhx8 in the development of the striatal interneurons, prompted us to investigate them as novel candidate genes for TS. We performed a comparative study of the expression of Lhx6 and Lhx8 and investigated genetic association with TS using two samples of trios (TSGeneSEE and German sample - 222 families). We show that Lhx6 and Lhx8 expression in the forebrain is evolutionarily conserved, underlining their possible importance in TS-related pathophysiological pathways. Our tagging-single nucleotide polymorphism (tSNP)-based association analysis was negative for association with LHX8. However, we found positive association with LHX6 in the TSGeneSEE sample (corrected P-value = 0.006 for three-site haplotype around SNP rs3808901) but no association in the sample of German families. Interestingly, the SNP allele that was identified to be significantly associated in the TSGeneSEE dataset, showed an opposite trend of transmission in the German dataset. Our analysis of the correlation of the LHX6 region with individual ancestry within Europe, revealed the fact that this particular SNP demonstrates a high degree of population differentiation and is correlated with the North to South axis of European genetic variation. Our results indicate that further study of the LHX6 gene in relation to the TS phenotype is warranted and suggest the intriguing hypothesis that different genetic factors may contribute to the etiology of TS in different populations, even within Europe.

Optimal processing of bone marrow trephine biopsy: the Hammersmith Protocol.

Specimens of bone marrow trephine biopsy (BMT) are transported and fixed in acetic acid-zinc-formalin fixative, decalcified in 10% formic acid-5% formaldehyde and processed with other specimens to paraffin-wax embedding. Sections, 1-microm-thick, are cut by experienced histotechnologists and used for haematoxylin and eosin, Giemsa, reticulin silver and other histological stains. Further, all immunohistochemical procedures used in the laboratory, including double immunostaining, can be used on these sections with no or minimal modifications. About 10,000 BMT specimens have been analysed using this procedure since 1997 and diseases involving the bone marrow have been classified successfully. More recently, standardised polymerase chain reaction-based analysis and mRNA in situ hybridisation studies have been conducted. Excellent morphology with good antigen, DNA and RNA preservation is offered by the Hammersmith Protocol.