A New Real-Time PCR for the Detection of Plasmodium ovale wallikeri

It has been proposed that ovale malaria in humans is caused by two closely related but distinct species of malaria parasites: P. ovale curtisi and P. ovale wallikeri. We have extended and optimized a Real-time PCR assay targeting the parasite’s small subunit ribosomal RNA (ssrRNA) gene to detect both these species. When the assay was applied to 31 archival blood samples from patients diagnosed with P. ovale, it was found that the infection in 20 was due to P. ovale curtisi and in the remaining 11 to P. ovale wallikeri. Thus, this assay provides a useful tool that can be applied to epidemiological investigations of the two newly recognized distinct P. ovale species, that might reveal if these species also differ in their clinical manifestation, drugs susceptibility and relapse periodicity. The results presented confirm that P. ovale wallikeri is not confined to Southeast Asia, since the majority of the patients analyzed in this study had acquired their P. ovale infection in African countries, mostly situated in West Africa.     

Pectolytic clostridia isolated from sugar beet pulp silages in Italy

Twenty-eight strains of pectolytic clostridia were isolated from sugar beet pulp silages. Seventeen non-pigmented strains were presumed to be Clostridium acetobutylicum ; the remaining 11 pigmented strains were similar to Cl. felsineum. The addition of molasses to sugar beet pulps favoured the growth of other bacteria, particularly lactic acid organisms, whereas pectolytic clostridia were only occasionally found. The pectolytic clostridia promoted the structure loss of simulated silages. The use of molasses in sugar beet pulp ensiling was suggested to prevent texture loss of the ensiled mass.     

Importance of some factors on the dimorphism of Candida albicans

The passage between the yeast and mycelial forms of Candida albicans B 311-10 was studied by using the minimal syntehtic medium of Shepherd et al. [19] modified without biotin and with low glucose concentrations. It was observed that biotin, aminoacids and particularly pH are not important factors in the dimorphism of C. albicans. The only factor of notable importance in the passage of yeast form to mycelial form in C. albicans was glucose concentration.     

Anthocyanin production in chl-rich and chl-poor seedlings

Screening by chlorophyll (Chl) affects photoconversion rates and photoequilibrium ratios of phytochrome in vivo and may cause distortion of the action spectra of photomorphogenesis (N Kazarinova-Fukshansky, M Seyfried, E Schäfer 1985 Photochem Photobiol 41: 689-702). Inhibitors that reduce the Chl content of seedlings are sometimes used in photomorphogenesis research to decrease the effects of Chl screening on the state of phytochrome in vivo. Streptomycin is one of the inhibitors that can be used for this purpose. The effects of streptomycin on phytochrome-mediated anthocyanin accumulation in young seedlings are significantly different in closely related systems. The use of `Chl-bleachers' in photomorphogenesis studies may produce undesirable side effects. At the level of the expression of a photoregulated response, the effects of differences in the state of phytochrome between water-grown Chl-rich and inhibitor-treated Chl-poor seedlings may be difficult to evaluate because they may be masked by the effects of the inhibitor on the response.     

Development of tool use in a macaque and a gorilla

The development of the capacity to use a stick as a tool was tested in a macaque (Macaca fuscata) and a gorilla (Gorilla gorilla gorilla) infants that had previously shown to be able to use strings and supports as dragging tools. Subjects were tested between 15 and 38 months of age. Different levels of competence between the subjects emerged over testing. The macaque developed a stereotyped strategy to cope with the problem, only getting random successes, whilst the gorilla developed a flexible strategy and revealed to be able to mentally represent the solution of the problem. In fact, when not successful using the stick, the gorilla thought out an alternative strategy, choosing and adapting a new object to use it as a tool.     

Comparison of spectral properties of phytochromes from different preparations

The spectral parameters of phytochrome in vitro described in several recent studies have been determined in purer and less degraded phytochrome samples than those used by Butler, Hendricks and Siegelman more than 20 years ago. There are considerable differences between the old and the new data. It seems logical that the researchers interested in phytochrome-mediated photomorphogenesis should use the new data for `native' phytochrome instead of the old ones, still in common use. A comparison of the spectral properties of phytochrome described in old and recent studies show that the differences among the `new' data are as large or larger, depending on the particular parameter and wavelength region considered, than the differences between `old' and `new' data. Therefore, if one should decide to use the new data instead of the old ones, one must also decide which set of new data should be used. The latter is a difficult choice. No matter what the choice, it should be open to revision in the future, the limitations associated with the choice should be noted, and the use of any set of spectral parameters of phytochrome should be made with extreme caution.     

Light, temperature, and anthocyanin production

Temperature affects the total amount, the time course, and the red/far-red effectiveness ratio of light-dependent anthocyanin production in Brassica oleracea L. seedlings. Some of the effects of temperature on anthocyanin production in cabbage are in agreement with the predictions of a model proposed by JK Wall and CB Johnson (1983 Planta 159: 387-397) for the effects of temperature on the state of phytochrome and on the expression of phytochrome-mediated high irradiance responses, but others are not. The lack of a complete agreement between experimental results and model predictions might be due to factors related to the experimental system used or to limitations of the model or both.