Penicillium persicinum, a new griseofulvin, chrysogine and roquefortine C producing species from Qinghai province, China

A unique Penicillium isolate from Chinese soil with terverticillate penicilli and ellipsoidal to cylindrical smooth-walled conidia, produces, in addition to the common metabolite ergosterol, copious amounts of an unknown peach-red pigment and the following secondary metabolites: griseofulvin, dechlorogriseofulvin, lichexanthone, roquefortine C, roquefortine D, chrysogine, 2-pyrovoylaminobenzamide, 2-acetyl-quinazolin-4(3H)-one. This isolate, CBS 111235, is described as Penicillium persicinum sp. nov., which belongs to subgenus Penicillium section Chrysogena but is morphologically similar to P. italicum. On the basis of the production of secondary metabolites it resembles P. griseofulvum and P. coprophilum. Sequence data using part of the beta-tubulin gene showed that it is phylogenetically related to P. chrysogenum and P. aethiopicum in section Chrysogena with which it shares both secondary metabolites and ability to grow at 37 degrees C.     

Oxanine DNA glycosylase activity from Mammalian alkyladenine glycosylase

Oxanine (Oxa) is a deaminated base lesion derived from guanine in which the N(1)-nitrogen is substituted by oxygen. This work reports the mutagenicity of oxanine as well as oxanine DNA glycosylase (ODG) activities in mammalian systems. Using human DNA polymerase beta, deoxyoxanosine triphosphate is only incorporated opposite cytosine (Cyt). When an oxanine base is in a DNA template, Cyt is efficiently incorporated opposite the template oxanine; however, adenine and thymine are also incorporated opposite Oxa with an efficiency approximately 80% of a Cyt/Oxa (C/O) base pair. Guanine is incorporated opposite Oxa with the least efficiency, 16% compared with cytosine. ODG activity was detected in several mammalian cell extracts. Among the known human DNA glycosylases tested, human alkyladenine glycosylase (AAG) shows ODG activity, whereas hOGG1, hNEIL1, or hNEIL2 did not. ODG activity was detected in spleen cell extracts of wild type age-matched mice, but little activity was observed in that of Aag knock-out mice, confirming that the ODG activity is intrinsic to AAG. Human AAG can excise Oxa from all four Oxa-containing double-stranded base pairs, Cyt/Oxa, Thy/Oxa, Ade/Oxa, and Gua/Oxa, with no preference to base pairing. Surprisingly, AAG can remove Oxa from single-stranded Oxa-containing DNA as well. Indeed, AAG can also remove 1,N(6)-ethenoadenine from single-stranded DNA. This study extends the deaminated base glycosylase activities of AAG to oxanine; thus, AAG is a mammalian enzyme that can act on all three purine deamination bases, hypoxanthine, xanthine, and oxanine.     

Multi-generational persistence of traditions in neighbouring meerkat groups

Reports of socially transmitted traditions based on behavioural differences between geographically separated groups of conspecifics are contentious because they cannot exclude genetic or environmental causes. Here, we report persistent differences between neighbouring groups of meerkats (Suricata suricatta) where extensive gene flow precludes genetic differentiation. Over 11 years, some groups consistently emerged later from their sleeping burrows in the morning than others, despite complete turnovers in group membership and the influx of immigrants. Group territories overlapped and, in many cases, the same sleeping burrows were used by different groups. Differences persisted even after accounting for effects of group size, weather and burrow characteristics, and were unrelated to food availability within territories. These results provide compelling evidence that the emergence times of meerkat groups represent conservative traditions.     

Low-dose simvastatin improves survival and ventricular function via eNOS in congestive heart failure

3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors increase endothelial nitric oxide synthase (eNOS) activity by multiple mechanisms. We previously reported that genetic overexpression of eNOS improves survival and cardiac function in congestive heart failure (CHF). In the present study, we tested the hypothesis that low-dose treatment with an 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor exerts beneficial effects on survival and/or cardiac function in a murine model of CHF. Mice were subjected to permanent ligation of the left coronary artery and randomized to receive either saline vehicle or simvastatin (0.25 mg/kg) 2 h after myocardial infarction and daily (0.25 mg/kg) for 7 days, followed by 21 days of administration every other day for a total duration of 28 days. Myocardial infarct size was not reduced by simvastatin therapy (P = not significant between groups). Simvastatin treatment did significantly (P < 0.05) improve survival (45%) compared with vehicle treatment (25%). In addition, simvastatin treatment significantly improved (P < 0.01) left ventricular function and significantly (P < 0.01) abrogated cardiac hypertrophy and pulmonary edema compared with vehicle treatment. The protective effects of simvastatin were abrogated by delayed initiation of treatment or genetic ablation of eNOS. In conclusion, low-dose simvastatin therapy significantly improves survival and cardiac function and reduces both cardiac hypertrophy and pulmonary edema via an eNOS-dependent mechanism in a murine model of CHF.     

Serotonin Turnover in Discrete Regions of Young Rat Brain After 24 h REM Sleep Deprivation

The present study has attempted to elucidate the alteration of serotonin turnover after 24 h REM sleep deprivation in different regions in brain of young rat. Sleep deprivation was induced by the inverted flowerpot technique. Results of this study show increased serotonin turnover after 24 h REM sleep deprivation in all the brain regions except in the hypothalamus. The decreased 5-HT ratio shows increased serotonin in the hypothalamus after 24 h sleep deprivation. This study indicates increased activity of serotonergic neurons in the hypothalamus after 24 h sleep deprivation. This also indicates that the hypothalamus plays a role in the immediate compensatory mechanism during 24 h REM sleep deprivation in young rats.     

A novel approach for screening immunogenic proteins in Penicillium marneffei using the DeltaAFMP1DeltaAFMP2 deletion mutant of Aspergillus fumigatus

Using serum from guinea-pigs immunized with a DeltaAFMP1DeltaAFMP2 deletion mutant of Aspergillus fumigatus to screen a cDNA library of A. fumigatus, we cloned a novel immunogenic 57-kDa protein in A. fumigatus. We also cloned its 55-kDa homologue in Penicillium marneffei, which was possibly related to amino acid biosynthesis and metabolism, with homologues present only in the subphylum Pezizomycotina of Ascomycota. The recombinant 55-kDa protein of P. marneffei reacted strongly with guinea-pig serum immunized with P. marneffei and with the sera of patients with P. marneffei infection. A similar approach could be applied to immunogenic protein screening in other microorganisms for serological diagnosis, epidemiological studies and the study of vaccines.     

Chlorophyll fluorescence performance of sweet almond [Prunus dulcis (Miller) D. Webb] in response to salinity stress induced by NaCl

One-year old sweet almond (Prunus dulcis) seedlings were submitted to four levels of salt stress induced by NaCl, namely 0.3, 0.5, 0.7, and 1.0 S m⁻¹. Effects of salt stress on a range of chlorophyll (Chl) fluorescence parameters (Chl FPs) and Chl contents were investigated in order to establish an eco-physiological characterization of P. dulcis to salinity. Salt stress promoted an increase in F₀, F_s, and F₀/F_m and a decrease in F_m, F′_m, F_v/F_m, q_P, ΔF/F′_m, F_v/F₀, and UQF_(rel), in almost all Chl fluorescence yields (FY) and FPs due to its adverse effect on activity of photosystem 2. No significant changes were observed for quenchings q_N, NPQ, and q_N(rel). The contents of Chl a and b and their ratio were also significantly reduced at increased salt stress. In general, adverse salinity effects became significant when the electric conductivity of the nutrient solution (EC_n) exceeded 0.3 S m⁻¹. The most sensitive salt stress indicators were F_v/F₀ and Chl a content, and they are thus best used for early salt detection in P. dulcis. Monitoring of a simple Chl FY, such as F₀, also gave a good indication of induced salt stress due to the significant correlations observed between the different Chl FYs and FPs. Even essential Chl FYs, like F₀, F_m, F′_m, and F_s, and mutually independent Chl FPs, like F_v/F₀ and q_P, were strongly correlated with each other.