Evidence of Intergenomic Relationships in Triploid Hybrids of Coffee (<Emphasis Type="Italic">Coffea sp.)</Emphasis> as Revealed by Meiotic Behavior and Genomic in Situ Hybridization

Interspecific hybrids involving the cultivated C. arabica (2n = 4x = 44, E^aE^aC^aC^a) and two related diploid species (2n = 2x = 22), C. eugenioides (EE) and C. liberica (LL), were produced and analyzed for their relative genome affinity using different complementary approaches, including chromosome association analysis, genomic in situ hybridization (GISH) and pollen fertility. The mean arm pairing frequency (c) and the relative affinity index (x) of triploid hybrids with known genome combinations were used as a measure of chromosome homology. Triploid hybrids were highly sterile as a result of meiotic abnormalities (fertility ranged from 1 to 15 %). Nevertheless, all hybrids exhibited a significant occurrence of genome affinities (x = 0.96 for E^aC^aE and 0.81 for E^aC^aL). Further analysis using the GISH approach revealed that C. eugenioides was more closely related to C. arabica than to C. liberica, which was in agreement with the ancestral history of the allotetraploid C. arabica. The absence of incompatibility barriers at the stylar level in the flowers of the triploid hybrids indicates the possibility of desirable gene transfer through breeding strategies.     

Optimisation of a quantitative polymerase chain reaction-based strategy for the detection and quantification of human herpesvirus 6 DNA in patients undergoing allogeneic haematopoietic stem cell transplantation

Human herpesvirus 6 (HHV-6) may cause severe complications after haematopoietic stem cell transplantation (HSCT). Monitoring this virus and providing precise, rapid and early diagnosis of related clinical diseases, constitute essential measures to improve outcomes. A prospective survey on the incidence and clinical features of HHV-6 infections after HSCT has not yet been conducted in Brazilian patients and the impact of this infection on HSCT outcome remains unclear. A rapid test based on real-time quantitative polymerase chain reaction (qPCR) has been optimised to screen and quantify clinical samples for HHV-6. The detection step was based on reaction with TaqMan^® hydrolysis probes. A set of previously described primers and probes have been tested to evaluate efficiency, sensitivity and reproducibility. The target efficiency range was 91.4% with linearity ranging from 10-10⁶ copies/reaction and a limit of detection of five copies/reaction or 250 copies/mL of plasma. The qPCR assay developed in the present study was simple, rapid and sensitive, allowing the detection of a wide range of HHV-6 loads. In conclusion, this test may be useful as a practical tool to help elucidate the clinical relevance of HHV-6 infection and reactivation in different scenarios and to determine the need for surveillance.     

Effect of neurotensin on pancreatic function in man

The effect of neurotensin on submaximally-stimulated hepatobiliary and pancreatic secretion was studied in 6 healthy subjects. An intravenous infusion of neurotensin 1.4 ± 0.3 pmol/kg/min, designed to reproduce plasma neurotensin immunoreactivity levels within the physiological range, produced a significant increase in pancreatic bicarbonate output. Plasma concentrations of pancreatic polypeptide rose by 83 ± 16 pmol/l and were associated with a small reduction in trypsin, but no significant change in bilirubin outputs.