The structure of eukaryotic and prokaryotic complex I

The structures of the NADH dehydrogenases from Bos taurus and Aquifex aeolicus have been determined by 3D electron microscopy, and have been analyzed in comparison with the previously determined structure of Complex I from Yarrowia lipolytica. The results show a clearly preserved domain structure in the peripheral arm of complex I, which is similar in the bacterial and eukaryotic complex. The membrane arms of both eukaryotic complexes show a similar shape but also significant differences in distinctive domains. One of the major protuberances observed in Y. lipolytica complex I appears missing in the bovine complex, while a protuberance not found in Y. lipolytica connects in bovine complex I a domain of the peripheral arm to the membrane arm. The structural similarities of the peripheral arm agree with the common functional principle of all complex Is. The differences seen in the membrane arm may indicate differences in the regulatory mechanism of the enzyme in different species.

Evaluation of the safety and pharmacokinetics of the multi-targeted receptor tyrosine kinase inhibitor sunitinib during embryo-fetal development in rats and rabbits

BACKGROUND

Angiogenesis plays a key role in embryo-fetal development and, based on nonclinical safety data, the majority of vascular endothelial growth factor (VEGF)-targeted antiangiogenic agents used in cancer therapy are not recommended during pregnancy. We investigated the effects of sunitinib (an oral inhibitor of multiple receptor tyrosine kinases [RTKs] including VEGF-receptors) on embryo-fetal development.

METHODS

Presumed-pregnant Sprague-Dawley rats and New Zealand White rabbits received repeated daily oral doses of sunitinib (0-30 mg/kg/day), during the major period of organogenesis. Clinical/physical examinations were performed throughout the gestation phase, and blood samples were collected to determine systemic exposure. Necropsy (including uterine examination) was performed on all animals and fetal morphology was examined.

RESULTS

The no-observed-adverse-effect level was 1-5 mg/kg/day for maternal toxicity and 3 mg/kg/day for developmental toxicity in rats; 1 and 0.5 mg/kg/day, respectively, in rabbits. Embryo-fetal toxicity included decreases in the number of live fetuses and increases in the numbers of resorptions and post-implantation/complete litter losses; these were observed at doses of > or =5 mg/kg/day in rats and 5 mg/kg/day in rabbits. Malformations included fetal skeletal malformations (generally thoracic/lumbar vertebral alterations) in rats and cleft lip/palate in rabbits. These developmental effects were observed at approximately 5.5- (rats) and approximately 0.3-times (rabbits) the human systemic exposure at the approved sunitinib dose (50 mg/day).

CONCLUSIONS

Similar effects have been reported with the prototype monoclonal antibody bevacizumab. As is typically observed for potent inhibitors of RTKs involved in angiogenesis, sunitinib was associated with embryo-fetal developmental toxicity in rats and rabbits at clinically relevant dose levels.

A phase I study of pemetrexed plus carboplatin or cisplatin with concurrent chest radiation therapy (CRT) for patients with locally advanced non-small cell lung cancer (LANSCLC)

7545

Background: Pemetrexed is a multi-targeted antifolate that inhibits the synthesis of both pyrimidines and purines. Pemetrexed is an effective new chemotherapeutic agent in advanced non-small cell lung cancer. Pemetrexed has also shown preclinical activity as a radiosensitizer in lung cancer. A phase I study was performed to establish the maximum tolerated dose (MTD) and phase 2 dose of carboplatin or cisplatin given with pemetrexed and CRT in LANSCLC. Methods: Patients (pts) with LANSCLC were enrolled. Initial intent was to establish the MTD of both weekly cisplatin and weekly carboplatin in combination with pemetrexed and CRT as an alternating two-arm phase I trial. Subsequently and based on early results from the CALGB 30407 trial (also evaluating the MTD of carboplatin), the protocol was amended to establish the safety of the planned phase II doses of cisplatin and carboplatin combined with pemetrexed 500 mg/m2 and given every 3 weeks with concurrent CRT. Dose limiting toxicity (DLT) was defined as ≥ Grade 3 hematologic or nonhematologic toxicity based on Common Terminology Criteria for Adverse Events (CTCAE) version 3.0. MTD was determined by occurrence of 2 DLTs among 6 pts in each cohort. Results: 22 pts were enrolled on 3 cohorts. All pts received pemetrexed, 9 with carboplatin AUC=2, 9 with cisplatin 30 mg/m2, and 4 with cisplatin 75 mg/m2. One DLT occurred in each of the carboplatin and cisplatin 30 mg/m2 cohorts, prompting enrollment of 3 additional patients. No DLTs were seen in the cisplatin 75 mg/m2 cohort. Conclusions: The MTD of cisplatin in combination with pemetrexed and CRT was not reached. Based on these results and those from CALGB 30407, either carboplatin AUC=5 or cisplatin 75 mg/m2 in combination with pemetrexed 500 mg/m2 given every 3 weeks with CRT appears to be well tolerated, and are currently being studied in a randomized phase II trial in pts with LANSCLC.

[Table: see text]

Sniffing out cancer from real breath samples by means of nanomaterial-based electronic nose device

e17552

Background: Several studies have shown that characteristic patterns of volatile organic compounds (VOCs) appear to be elevated in the alveolar breath of cancer patients, as compared to healthy controls. It has been shown, that VOCs’ composition acts as a fingerprint for the distinction of a certain cancer from other cancers, including the cases where various cancers have similar type of biomarkers. The goal of the current study is to establish a background to ultimately achieve a simple-to-use device that can detect such patterns of cancer when exhaling into it. Methods: Breath samples were collected from 40 healthy volunteers and 75 patients having known conditions in six main categories: (I) 40 healthy controls; (II) 30 patients with lung cancer; (III) 15 patients with breast cancer; (IV) 20 patients with colon cancer; (V) 5 patients with prostate cancer; and (VI) 5 patients with head and neck cancer. The breath of the volunteers was examined by means of gas chromatography linked with mass spectrometry technique (GC-MS) as well as by an electronic nose device that is based on molecularly modified Au nanoparticles to check the feasibility of the electronic nose in cancer detection via breath samples Results: GC-MS results showed that each category of cancer has a unique pattern (or mixture) of VOCs. In parallel to these findings, results indicate the ability of nanomaterial-based electronic nose devices to differentiate between “healthy” and “cancerous” breath, and, furthermore, between the breath of patients with different cancer types, with >92% sensitivity. Conclusions: The electronic nose technology has a high potential for assessing various types of cancer via simple exhalation procedure. The results provide a launching pad towards obtaining an inexpensive, compact tool that is amenable to widespread screening and that has a potential for direct and real-time monitoring (2–3 minutes only).

No significant financial relationships to disclose.

Salacia oblonga root decreases cardiac hypertrophy in Zucker diabetic fatty rats: inhibition of cardiac expression of angiotensin II type 1 receptor

AIMS

We investigated the effect of the water extract of Salacia oblonga (SOE), an ayurvedic antidiabetic and antiobesity medicine, on obesity and diabetes-associated cardiac hypertrophy and discuss the role of modulation of cardiac angiotensin II type 1 receptor (AT(1)) expression in the effect.

METHODS

SOE (100 mg/kg) was given orally to male Zucker diabetic fatty (ZDF) rats for 7 weeks. At the end-point of the treatment, the hearts and left ventricles were weighed, cardiomyocyte cross-sectional areas were measured, and cardiac gene profiles were analysed. On the other hand, angiotensin II-stimulated embryonic rat heart-derived H9c2 cells and neonatal rat cardiac fibroblasts were pretreated with SOE and one of its prominent components mangiferin (MA), respectively. Atrial natriuretic peptide (ANP) mRNA expression and protein synthesis and [(3)H]thymidine incorporation were determined.

RESULTS

SOE-treated ZDF rats showed less cardiac hypertrophy (decrease in weights of the hearts and left ventricles and reduced cardiomyocyte cross-sectional areas). SOE treatment suppressed cardiac overexpression of ANP, brain natriuretic peptide (BNP) and AT(1) mRNAs and AT(1) protein in ZDF rats. SOE (50-100 microg/ml) and MA (25 micromol) suppressed angiotensin II-induced ANP mRNA overexpression and protein synthesis in H9c2 cells. They also inhibited angiotensin II-stimulated [(3)H]thymidine incorporation by cardiac fibroblasts.

CONCLUSIONS

Our findings demonstrate that SOE decreases cardiac hypertrophy in ZDF rats, at least in part by inhibiting cardiac AT(1) overexpression. These studies provide insights into a potential cardioprotective role of a traditional herb, which supports further clinical evaluation in obesity and diabetes-associated cardiac hypertrophy.

A randomized phase 3 trial of gemcitabine with or without carboplatin in performance status 2 (PS2) patients (pts) with advanced (stage IIIB with pleural effusion or stage IV) non-small cell lung cancer (NSCLC)

7533

Background: The optimal treatment of patients with advanced NSCLC and PS2 has not been resolved. A retrospective analysis of 99 pts with PS2 in CALGB 9730 (Lilenbaum, JCO 2005) demonstrated improved survival associated with combination carboplatin- paclitaxel versus paclitaxel alone (median overall survival=4.7 vs. 2.4 mos., p=.019). Gemcitabine-carboplatin (GC) is an active doublet in advanced NSCLC and is at least as active as paclitaxel-carboplatin (PC) in PS2 pts (ECOG 1599, Tester ASCO 2004). A prospective validation of the activity of GC is needed, which is addressed by comparing GC versus gemcitabine (G) alone in this setting. Methods: 161 chemonaïve pts with advanced NSCLC and PS2 were randomly assigned to G 1250 mg/m2 alone on Days 1,8 or GC (G 1000mg/m2 Days 1,8 followed by C AUC 5 on Day 1). Cycles were repeated every 21 days for 6 cycles or until disease progression or intolerable toxicity. Primary endpoint was median survival. Conclusions: GC resulted in an improved response rate among NSCLC pts with PS2 over G alone. As expected, G3–4 toxicities were greater with GC. Overall survival data will be reported at the time of the meeting.

[Table: see text] [Table: see text]

Insulin-like growth factor signaling regulates zebrafish embryonic growth and development by promoting cell survival and cell cycle progression

Although much is known about the global effects of insulin-like growth factor 1 receptor (IGF1R)-mediated signaling on fetal growth and the clinical manifestations resulting from IGF/IGF1R deficiencies, we have an incomplete understanding of the cellular actions of this essential pathway during vertebrate embryogenesis. In this study, we inhibited IGF1R signaling during zebrafish embryogenesis using antisense morpholino oligonucleotides or a dominant-negative IGF1R fusion protein. IGF1R inhibition resulted in reduced embryonic growth, arrested development and increased lethality. IGF1R-deficient embryos had significant defects in the retina, inner ear, motoneurons and heart. No patterning abnormalities, however, were found in the brain or other embryonic tissues. At the cellular level, IGF1R inhibition increased caspase 3 activity and induced neuronal apoptosis. Coinjection of antiapoptotic bcl2-like mRNA attenuated the elevated apoptosis and rescued the retinal and motoneuron defects, but not the developmental arrest. Subsequent cell cycle analysis indicated an increased percentage of cells in G1 and a decreased percentage in S phase in IGF1R-deficient embryos independent of apoptosis. These results provide novel insight into the cellular basis of IGF1R function and show that IGF1R signaling does not function as an anteriorizing signal but regulates embryonic growth and development by promoting cell survival and cell cycle progression.

Experimental infections of pigs and mice with selected genotypes of Ascaris

Extending a previous investigation of the genotypic variability within Ascaris from humans and pigs, experimental infections of mice and pigs with selected genotypes of Ascaris were performed in the present study to explore possible host affiliation. Initial findings indicate that there is a significant difference in the ability of Ascaris eggs of genotype G1 (derived from human) and G3 (derived from pig) to infect and establish as larvae in mice and as adults in pigs, supporting the difference in the frequencies of the genotypes reported previously in natural Ascaris populations in pigs and humans in areas in China endemic for ascariasis.

Effect of Moisture and Temperature on Disease of Green Foxtail Caused by Drechslera gigantea and Pyricularia setariae

Leaf wetness duration, temperature, intermittent leaf wetness, and delayed leaf wetness were investigated for their influence on disease of green foxtail caused by Drechslera gigantea and Pyricularia setariae to determine the potential of these two fungi as bioherbicide agents in the Canadian prairies. For both fungi, disease severity increased with increasing leaf wetness duration at 15, 20, 25, 30, and 32°C. At 10°C, conidia of both fungi showed minimal germination, regardless of leaf wetness duration; however, an increase in conidial germination, appressoria formation, and disease occurred at 15°C. Conidia of both species showed 80% or greater germination at all temperatures above 15°C, whereas the optimum temperatures for appressoria formation by D. gigantea and P. setariae were 23 and 25°C, respectively. Maximum disease occurred after 48 h of leaf wetness at 32°C for D. gigantea and at 25°C for P. setariae. Disease caused by both fungi decreased when 4 h of continuous leaf wetness was followed by a 20-h dry period, and after an 8-h delay in leaf wetness following inoculation. Both fungi required immediate and prolonged periods of leaf wetness at temperatures of 15°C and above to cause severe disease on green foxtail. The moisture requirements of these fungi may limit their effectiveness as bioherbicide agents in the semi-arid Canadian prairies.

[Measurement of cyclosporine A in whole blood by high performance liquid chromatography(HPLC)]

Whole blood was extracted by ether under base using cyclosporine D as internal standard. The extraction was evaporated and reconstituted. The interferences were further removed by hexane. The reconstitution was injected into a C18 reversed-phase column at 70 degrees C, which was eluted with a mobile phase of acetonitrite/methanol/water(60/10/30, v/v) at flow rate 1.6 ml.min-1 and monitored at 210 nm. Three levels of BIO-RAD cyclosporine A(whole blood) calibrator were measured, all the results were within expected range. The detection limit was 25 ng.ml-1. The linearity was at least within 50-1,000 ng.ml-1. Analytical recoveries were 99.6%-108.8%. The within-run cv and between-run CV were 7.2% and 9.3%, respectively.

NMR structure reveals intramolecular regulation mechanism for pheromone binding and release

Odorants are transmitted by small hydrophobic molecules that cross the aqueous sensillar lymph surrounding the dendrites of the olfactory neurons to stimulate the olfactory receptors. In insects, the transport of pheromones, which are a special class of odorants, is mediated by pheromone-binding proteins (PBPs), which occur at high concentrations in the sensillar lymph. The PBP from the silk moth Bombyx mori (BmPBP) undergoes a pH-dependent conformational transition between the forms BmPBP(A) present at pH 4.5 and BmPBP(B) present at pH 6.5. Here, we describe the NMR structure of BmPBP(A), which consists of a tightly packed arrangement of seven alpha-helices linked by well defined peptide segments and knitted together by three disulfide bridges. A scaffold of four alpha-helices that forms the ligand binding site in the crystal structure of a BmPBP-pheromone complex is preserved in BmPBP(A). The C-terminal dodecapeptide segment, which is in an extended conformation and located on the protein surface in the pheromone complex, forms a regular helix, alpha(7), which is located in the pheromone-binding site in the core of the unliganded BmPBP(A). Because investigations by others indicate that the pH value near the membrane surface is reduced with respect to the bulk sensillar lymph, the pH-dependent conformational transition of BmPBP suggests a novel physiological mechanism of intramolecular regulation of protein function, with the formation of alpha(7) triggering the release of the pheromone from BmPBP to the membrane-standing receptor.

Analysis of the 1991-2000 influenza epidemic in Guangdong Province, China

Influenza surveillance networks in Guangdong were established to investigate the epidemiological characteristics of influenza and influenza epidemics. Influenza activity peaked annually from March to July in Guangdong in 1991-2000; influenza H3N2 predominated in the epidemic (7 years of 10); the outbreak of influenza in 1996 was the remarkable result of antigenic drift of H3N2 strain. Ten isolates of H9N2 strains were discovered from human subjects in 1998 and 1999: chicken strains isolated after the Hong Kong fowl influenza outbreak. It was found that there was just one influenza activity season per annum in Guangdong and that the influenza H3N2 subtype still predominates in Guangdong. Further research into the pathogenicity of influenza H9N2 in humans warranted.

Identification and cloning of a pheromone-binding protein from the Oriental beetle, Exomala orientalis

We have identified and cloned a pheromone-binding protein (EoriPBP) from the Japanese and American populations of the Oriental beetle, Exomala orientalis (Coleoptera: Scarabaeidae). The protein showed more than 90% amino acid identity to the previously identified pheromone-binding proteins from Popilliajaponica (PjapPBP) and Anomala osakana (AosaPBP), as well as to one of the odorant-binding proteins from Phyllopertha diversa (PdivOBP1). EoriPBP has 116 amino acids, with a calculated molecular mass of 12,981 Da. pI of 4.3, and six highly conserved cysteine residues. 5'-RACE amplifications led to the characterization of a signal peptide with 19 amino acids. The signal peptide showed high amino acid identity to the signal peptide for AosaPBP. Comparison of the amino acid sequences of the PBPs involved in the detection of similar ligands, i.e., monounsaturated lactones and ketone, suggests that the most variable residues among the PBPs from E. orientalis, P. japonica, and A. osakana are probably the most discriminating residues. As with the pheromone-binding protein from Bombyx mori, the residues at positions 61, 64, 71, and 82 in EoriPBP, PajpPBP, and AosaPBP, which are either valine, leucine, isoleucine, or methionine, are likely to be specificity determinants.