Mutational analysis of the human cyclin-dependent kinase inhibitor p27kip1 in primary breast carcinomas

The human p27^kip1 gene encodes a cyclin-dependent kinase inhibitor implicated in the negative regulation of the cell cycle. In order to elucidate the possible role of p27 mutations in the development or progression of human breast cancer, we have studied the occurrence of genetic abnormalities in this gene in a series of 30 primary breast carcinomas. Direct sequence analysis of the polymerase chain reaction amplified human p27 gene revealed the occurrence of two sequence variations with respect to the reported sequence; both variants were also present in the lymphocyte DNA from the same patients. First, a silent G to A change at codon 142 (Thr) was detected in a single case. Second, a T to G transversion at codon 109, resulting in a Val to Gly change, was observed in eight tumour DNA samples (26%) and in 31 out of 80 unrelated normal individuals (39%). This latter change creates a BglI restriction site that might be useful for genetic analysis of human tumours. Despite the occurrence of these polymorphisms, we did not however find any evidence of somatic mutations in the coding region of the p27 gene. On the basis of these results, we suggest that alterations in the integrity of the human p27 gene are not common events in human breast carcinomas.     

The physiological basis of seed dormancy in Avena fatua. II. On the involvement of alternative respiration in the stimulation of germination by sodium azide

Chromatography on DEAE-cellulose of an extract from etiolated leaves of sorghum ( Sorghum vulgare Pers. cv. INRA 450), a C₄ plant, gave only one form of phosphoenol pyruvate carboxylase with functional and regulatory properties of a C₃ type plant enzyme. Greening of the leaves resulted in a significant increase in activity. This increase was due to the appearance of a new form of the enzyme, which eluted at lower ionic strength and exhibited new properties. This form was glucose-6-P activated and showed a sigmoidal curve response to the concentration of the substrate phosphoerralpyruvate. These kinetic properties are typical of a C₄ plant enzyme.     

Immunomodulatory effects of Streptococcus suis capsule type on human dendritic cell responses, phagocytosis and intracellular survival

Streptococcus suis is a major porcine pathogen of significant commercial importance worldwide and an emerging zoonotic pathogen of humans. Given the important sentinel role of mucosal dendritic cells and their importance in induction of T cell responses we investigated the effect of different S. suis serotype strains and an isogenic capsule mutant of serotype 2 on the maturation, activation and expression of IL-10, IL-12p70 and TNF-α in human monocyte-derived dendritic cells. Additionally, we compared phagocytosis levels and bacterial survival after internalization. The capsule of serotype 2, the most common serotype associated with infection in humans and pigs, was highly anti-phagocytic and modulated the IL-10/IL-12 and IL-10/TNF-α cytokine production in favor of a more anti-inflammatory profile compared to other serotypes. This may have consequences for the induction of effective immunity to S. suis serotype 2 in humans. A shielding effect of the capsule on innate Toll-like receptor signaling was also demonstrated. Furthermore, we showed that 24 h after phagocytosis, significant numbers of viable intracellular S. suis were still present intracellularly. This may contribute to the dissemination of S. suis in the body.     

3-Hydroxy fatty acids in saliva as diagnostic markers in chronic periodontitis

Saturated straight- and branched-chain 3-hydroxy fatty acids (3-OH FAs) of 10-18 carbon chain lengths were determined in saliva from 27 individuals with chronic periodontitis and 18 healthy individuals by using gas chromatography-tandem mass spectrometry. Of the 14 different 3-OH FAs detected, 3-OH-C(i17:0) was the most abundant in the periodontitis samples while 3-OH-C(14:0) was the most abundant in the healthy individuals. Considering the relative percentages of 3-OH-C(12:0), 3-OH-C(14:0), 3-OH-C(i17:0), and 3-OH-C(17:0), 95.6% of all cases were correctly classified as healthy individuals or periodontitis patients by means of discriminant analysis. The sensitivity, specificity, positive predictive value and negative predictive value of 3-OH FA analysis in diagnosing peridontitis were, respectively, 0.92, 1.00, 1.00, and 0.90. The results indicate that 3-OH FA analysis of saliva samples is a useful diagnostic method in chronic periodontitis.     

Necrodane monoterpenoids from Lavandula luisieri

Four new irregular monoterpenoids were identified in the essential oil of Lavandula luisieri (Rozeira) Riv. Mart., a Labiatae endemic to the Iberian Peninsula. By means of spectroscopic and chemical methods, they were characterised as 3,5-dimethylene-1,4,4-trimethylcyclopentene, 5-methylene-2,3,4,4-tetramethylcyclopent-2-enone, 3,4,5,5-tetramethylcyclopenta-1,3-dienecarboxaldehyde and 3,4,5,5-tetramethylcyclopenta-1,3-dienecarboxylic acid. L. luisieri essential oil and extract showed a good activity against Candida albicans and gram positive bacteria: Staphylococcus aureus, S. epidermidis and S. pyogenes.     

Immature T lymphocytes in human cord blood identified by monoclonal antibodies: a model for the study of the differentiation pathway of T cells in humans

The reactivity of human cord blood lymphocytes was assessed against a panel of monoclonal antibodies (MoAb). The mean proportion of OKT3+ cells (pan-T) was significantly lower in cord blood (52 +/- 13.8%; mean +/- SD) compared with that of adult blood (75 +/- 8.9%) and paralleled well with the E-rosette-forming capacity (50 +/- 16.3%). Both the proportions of OKT4+ cells (helper/inducer phenotype) and of OKT8+ cells (suppressor/cytotoxic phenotype) were significantly reduced in cord blood (43 +/- 11.8% vs 50.3 +/- 7.4% and 20 +/- 10.3% vs 25.6 +/- 6.0%, respectively), while the overall OKT4/OKT8 ratio was increased compared with adult blood (2.87 +/- 1.83 vs 2.04 +/- 0.61). Unlike adult blood, in 30 of the 35 samples of cord blood an overlap was observed between the total proportion of OKT4+ and OKT8+ cells (65 +/- 15.2%) and that of OKT3+ cells (52 +/- 14.3%). Although small numbers of cells coexpressing both antigens were occasionally found, double-staining analysis showed that the overlap in cord blood was mostly due to an expanded proportion of OKT3 (Leu-4)-/OKT8 (Leu-2)+ cells. Relevant proportions of OKT6+ (common thymocyte antigen) and OKT10+ (thymocytes, activated T cells, precursor cells) cells were found in cord blood as opposed to adult blood (10.8 +/- 8.6% vs 0.6 +/- 0.6% and 67 +/- 18.0% vs 8 +/- 2.1%, respectively), while terminal deoxynucleotidyl transferase-positive cells were observed only in two samples of cord blood. A small proportion of T cells (E-rosette+) reacted with the MoAb OKIa1 (HLA-DR). Finally, the proportion of cord blood cells recognized by the MoAb Leu-7 (HNK-1 clone) was almost negligible compared with adult blood (2.8 +/- 2.4% vs 15 +/- 7.5%). These data confirm the immaturity and heterogeneity of cord blood lymphocytes and demonstrate the presence at birth of circulating lymphocytes which express a surface phenotype reminiscent of that found in the late stages of intrathymic differentiation and in some human T-cell leukemias. Human cord blood may thus represent a suitable model for the study of the differentiation pathway of normal and pathological T-cells in humans.