Ameliorating role of caffeic acid phenethyl ester (CAPE) against isoniazid-induced oxidative damage in red blood cells

Isoniazid (INH) still remains a first-line drug both for treatment and prophylaxis of tuberculosis, but various organs toxicity frequently develops in patients receiving this drug. We aimed to investigate possible toxic effects of INH on rat red blood cells (RBCs), and to elucidate whether Caffeic acid phenethyl ester (CAPE) prevents a possible toxic effect of INH. Experimental groups were designed as follows: control group, INH group, INH + CAPE group. Compared with the control, the INH caused a significant increase in superoxide dismutase (SOD) activity and malondialdehyde (MDA) levels, and a decrease in glutathione peroxidase (GSH-Px) and catalase (CAT), which are recently used to monitor the development and extent of damage due to oxidative stresses. CAPE administration to INH group ameliorated above changes due to INH.     

Beneficial role of aminoguanidine on acute cardiomyopathy related to doxorubicin-treatment

Doxorubicin (DOX) is a broad-spectrum anthracycline antibiotic that has cardiotoxicity as a major side effect. One mechanism of this toxicity is believed to involve the reactive oxygen radical species (ROS); these agents likely account for the pathophysiology of DOX-induced cardiomyopathy. Aminoguanidine (AG) is an effective antioxidant and free radical scavenger which has long been known to protect against ROS formation. We investigated the effects of AG on DOX-induced changes in thiobarbituric acid reactive substances (TBARS) and reduced glutathione (GSH) content. The rats were divided into four groups:1) Control; 2) DOX group; injected intraperitoneally (i.p.) with DOX 20 mg/kg in a single dose 3) AG-treated group; injected i.p. in single dose of 20 mg/kg DOX plus 100 mg/kg AG 1 h before the DOX for 3 days, 4) AG group; injected i.p. with AG 100 mg/kg for 3 days. DOX administration to control rats increased TBARS and decreased GSH levels. AG administration before DOX injection caused significant decrease in TBARS and increase in GSH levels in the heart tissue when compared with DOX only. Morphological changes, including severe myocardial fibrosis and inflammatory cell infiltration were clearly observed in the DOX-treated heart. AG reversed the DOX-induced heart damage. Therefore AG could protect the heart tissue against free radical injury. The application of AG during cancer chemotherapy may attenuate tissue damage and improve the therapeutic index of DOX.     

Physiological and chemical indicators for early and late stages of sepsis in conscious rats

Endotoxin shock is a major cause of death in patients with septicemia. Endotoxin induces nitric oxide (NO) production and causes tissue damage. In addition, the release of oxygen free radicals has also been observed in endotoxin shock and was found to be responsible for the occurrence of multiple organ failure. The purpose of the present study was to evaluate suitable indicators for early and late stages of endotoxin shock. The experiments were designed to induce endotoxin shock in conscious rats by means of anEscherichia coli lipopolysaccharide (LPS) injection. Arterial pressure (AP) and heart rate (HR) were continuously monitored for 72 h after LPS administration. The maximal decrease in AP and increase in HR and nitrate/nitrite level occurred at 9–12 h following LPS administration. The white blood cell (WBC) count had decreased at 3 h. Hydroxyl radical (methyl guanidine, MG) decreased rapidly after LPS administration. Plasma levels of blood urea nitrogen (BUN), creatinine (Cr), lactic dehydrogenase (LDH), creatine phosphokinase (CPK), and glutamic oxaloacetic transaminase increased before the rise of amylase. Our results suggest that changes in AP, HR, WBC, free radicals, and chemical substances (BUN, Cr) can possibly serve as approximate indicators for the early stage of endotoxin shock. Severe multiple organ damage may be caused by amylase release in the late stage of endotoxin shock.     

A journey through time: exploring temporal patterns amongst digitized plant specimens from Australia

Online access to species occurrence records has opened new windows into investigating biodiversity patterns across multiple scales. The value of these records for research depends on their spatial, temporal, and taxonomic quality. We assessed temporal patterns in records from the Australasian Virtual Herbarium, asking: (1) How temporally consistent has collecting been across Australia? (2) Which areas of Australia have the most reliable records, in terms of temporal consistency and inventory completeness? (3) Are there temporal trends in the completeness of attribute information associated with records? We undertook a multi-step filtering procedure, then estimated temporal consistency and inventory completeness for sampling units (SUs) of 50?km ×?50?km. We found temporal bias in collecting, with 80% of records collected over the period 1970–1999. South-eastern Australia, the Wet Tropics in north-east Queensland, and parts of Western Australia have received the most consistent sampling effort over time, whereas much of central Australia has had low temporal consistency. Of the SUs, 18% have relatively complete inventories with high temporal consistency in sampling. We also determined that 25% of digitized records had missing attribute information. By identifying areas with low reliability, we can limit erroneous inferences about distribution patterns and identify priority areas for future sampling.     

Consistent associations with beneficial bacteria in the seed endosphere of barley (Hordeum vulgare L.)

The importance of the plant microbiome for host fitness has led to the concept of the “plant holobiont”. Seeds are reservoirs and vectors for beneficial microbes, which are very intimate partners of higher plants with the potential to connect plant generations. In this study, the endophytic seed microbiota of numerous barley samples, representing different cultivars, geographical sites and harvest years, was investigated. Cultivation-dependent and -independent analyses, microscopy, functional plate assays, greenhouse assays and functional prediction were used, with the aim of assessing the composition, stability and function of the barley seed endophytic bacterial microbiota. Associations were consistently detected in the seed endosphere with Paenibacillus, Pantoea and Pseudomonas spp., which were able to colonize the root with a notable rhizocompetence after seed germination. In greenhouse assays, enrichment with these bacteria promoted barley growth, improved mineral nutrition and induced resistance against the fungal pathogen Blumeria graminis. We demonstrated here that barley, an important crop plant, was consistently associated with beneficial bacteria inside the seeds. The results have relevant implications for plant microbiome ecology and for the holobiont concept, as well as opening up new possibilities for research and application of seed endophytes as bioinoculants in sustainable agriculture.     

Failure of neutralizing gp120 monoclonal antibodies to prevent HIV infection of choriocarcinoma-derived trophoblasts

Although placental trophoblasts, the only fetal cells in direct contact with infectious maternal blood, can be infected with HIV, the precise cause for the low transmission rate of virus across the placental barrier is unknown. One of the most common conjectures is that maternal anti-HIV antibodies (Abs) contribute to the protection of the fetus. This hypothesis has been tested in vitro by infecting the CD4-negative placental trophoblast line, BeWo, with HIV-1_IIIB in the presence of serial dilutions of neutralizing monoclonal Abs against the V3 loop (No. 694) or CD4-binding conformational domain (No. 588). The results, based on measurement of p24 production from virus-exposed cells, reveal that the titers of Abs, adequate in preventing the infection of control MT-4 T lymphocytes, were less effective in protecting trophoblasts. Furthermore, PCR analysis of HIV DNA formed after a single round of infection has shown no significant decrease in the number of viral copies in Ab-protected BeWo cells. An anti-HIV serum from a pregnant woman did also have no effect. Although our in vitro observations do not necessarily apply to the in vivo situation, the results suggest that the humoral immune response sustained by neutralizing Abs may be able to protect T lymphocytes, but not placental trophoblasts. The findings are consistent with recent clinical studies demonstrating a lack of correlation between the presence of neutralizing anti-HIV Abs in pregnant women and HIV transmission in utero.     

Female Choice in the Synchronously Waving Fiddler Crab Uca annulipes

In the fiddler crab, Uca annulipes, males attract receptive females into their burrows by waving their greatly enlarged major claw. We have previously shown that males clustered around a female wave in close synchrony. Females may have a preference for leading signals and synchronised waving may arise as an epiphenomenon of competition between males to signal first. Indeed, the males in clusters that females approach and visit in their burrows are more likely to produce leading waves than are their neighbours. Here we document two other differences in the waving behaviour of visited males and their neighbours. First, visited males complete the downward component of the wave more rapidly than their neighbours. Second, the interval between the end of one wave and the start of the next is shorter for visited males. How can waving be synchronous if visited males wave faster than their neighbours? While only 9% (40/431) of waves by neighbours did not overlap those of the visited male, 22% (110/501) of visited male waves did not overlap the wave of a focal neighbour (111 visited male-neighbour dyads). Hence, while overlapping waves are nearly synchronous, visited males produce additional, ‘nonoverlapping’ waves that result in a higher wave rate than that of their neighbours.     

Photosynthetic activity of developing leaves of Zea mays is less affected by heat stress than that of developed leaves

Various physiological and biochemical characters of a leaf change with stages of its ontogeny. It is likely that the photosynthetic functions of leaves of different ontogeny have different levels of heat tolerance. This study was initiated to analyze the photosynthetic heat tolerance of fully-developed, nearly-developed (more than 2/3 expanded) and developing (10–12 cm visible) leaves of two maize genotypes, F223 and F250. The results indicate that the photosynthetic CO₂ assimilation rate (P_n) of developing leaves was less affected by heat stress (42°C in the dark for 90 min) than that of developed leaves. The impaired P_n recovered within 24 h in the developing leaves, while the P_n of developed and nearly-developed leaves did not reach the non-stress level, even after 72 h. The P_n of the developed leaves of genotype F250 was less affected by heat stress than that of genotype F223. After heat stress, the slightly affected P_n of the developing leaf was associated with the almost unchanged photochemical efficiency of photosystem II (F_v/F_m) and the quantum yield of photosystem II electron transport. The chlorophylls a and b were degraded by heat stress; the degradation was pronounced in the developed leaves. As a result of heat stress, the antheraxanthin and zeaxanthin of the xanthophyll cycle accumulated in both the nearly-developed and developed leaves but not in the developing leaves. Injury to the plasma membrane due to heat stress was much less severe in developing leaves than that in the developed leaves. From the physiological characters which we determined it would appear that the P_n functions of the developing leaves are more resistant to heat stress than those of nearly-developed and developed leaves.