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.

Evolution of antifungal susceptibility among Candida species isolates recovered from human immunodeficiency virus-infected women receiving fluconazole prophylaxis

The effect of fluconazole on the susceptibility of Candida isolates recovered from women infected with human immunodeficiency virus (HIV) was evaluated in a randomized, double-blind, placebo-controlled trial. Women with CD4(+) cell counts of < or =300 cells/mm(3) received either fluconazole (200 mg/week) or placebo as prophylaxis. The antifungal susceptibility of specimens was evaluated. One patient who received fluconazole and 2 patients assigned to placebo had Candida albicans isolates recovered that were resistant to fluconazole (MIC, > or =64 microg/mL). Eleven patients assigned fluconazole and 4 patients assigned placebo had non-albicans Candida strains (all Candida glabrata) recovered that were resistant to fluconazole. There was significant azole cross-resistance among the non-albicans Candida species isolates. Although the rate of azole resistance did not significantly increase after fluconazole prophylaxis, there was a trend toward more in vitro azole resistance in C. glabrata isolates from patients assigned fluconazole. Moreover, the majority of resistant vaginal isolates of Candida species were recovered after initiation of open-label fluconazole use.

[In vitro modulation of the invasive and metastatic potentials of human hepatocellular carcinoma by interlukin-2]

OBJECTIVE

To investigate the effects of interlukin-2 (IL-2) on the in vitro invasiveness and the expression of several cell surface antigens related to invasive and metastatic potentials of human hepatocellular carcinoma (HCC) QGY-7701 cell line.

METHODS

QGY-7701 cells were incubated with high concentration of IL-2 or low concentration of IL-2 in different time. The expression of ICAM-1, CD(44) and HLA-I of the tumor cells was determined by fluorescence-activated cell sorter (FACS) analysis The tumor cell binding affinity to extracellular matrix components was measured by cell attachment assay. The degree of homotypic aggregation was quantified by cell aggregation assay.

RESULTS

IL-2 treatment exhibited enhanced expression of ICAM-1 (from 8.3% to 20.5% after high concentration of IL-2 treatment and 17.3% after low concentration of IL-2 treatment) and HLA-I (from 9.8% to 25.4% and 22.1%, respectively after high and low concentration of IL-2 treatment), suppression of CD(44) (from 26.4% to 12.5% and 11.6%, respectively) on HCC cell line and decreased binding affinity to type IV collagen (from 23.5% to 12.4%, 32.3% to 13.8%, 45.7% to 19.6% at 20 min, 40 min and 60 min, respectively after high concentration of IL-2 treatment, and 9.6%, 12.5% and 17.9%, respectively after low concentration of IL-2 treatment) and fibronectin (from 18.6% to 14.1%, 31.2% to 18.4%, 44.5% to 20.5% at 20 min, 40 min and 60 min, respectively after high concentration of IL-2 treatment, and 14.6%, 17.1% and 18.9%, respectively after low concentration of IL-2 treatment) and the degree of homotypic aggregation (from 58.3% to 26.5%, 85.4% to 37.6%, 88.6% to 42.3% at 20 min, 40 min and 60 min, respectively after high concentration of IL-2 treatment, and 25.0%, 36.4% and 42.6%, respectively after low concentration of IL-2 treatment)of HCC cells.

CONCLUSIONS

IL-2 may directly alter tumor properties associated with invasive and metastatic phenotypes of HCC cells, and can inhibit the invasive and metastatic potentials of HCC cells.

Vitreous cavity-associated immune deviation induced by retinal S antigen

PURPOSE

To determine whether the vitreous cavity (VC) supports the induction of deviant immune responses to retinal soluble(S) antigen and to observe the influence of interleukin-1 (IL-1) on the immunologic properties of the VC.

METHODS

Retinal S antigen was inoculated into the anterior chamber(AC) and the VC in Wistar rats. Seven days after antigen inoculation, the recipient animals were immunized with S antigen and complete Freund's adjuvant. Delayed-type hypersensitivity (DTH) was assessed by footpad challenge. To alter systemic immune conditions, IL-1 was administrated by intraperitoneal injection.

RESULTS

Antigen-specific DTH did not develop in rats in which S antigen was injected into the AC and the VC. By contrast, when IL-1 administrated systemically, S antigen was injected into the AC and VC elicited strong DTH.

CONCLUSION

The VC supports immune deviation for soluble antigen by acitivity suppressing antigen-Specific DTH. Systemic administration of exogenous IL-1 eliminates the capacity of the VC to support immune deviation to soluble antigen locally injected.

[Effect of benzo(a)pyrene on antioxidant enzyme activities in Boleophthalmus pectinirostris liver]

The effect of different BaP concentrations on the activities of superoxide dismutase(SOD), glutathione peroxidase (GPx) and catalase(CAT) in Boleophthalmus pectinirostris liver was studied under experimental condition. The results showed that the activities of antioxidant enzymes did not change too much with BaP exposure in lower concentration, whereas the SOD and GPx activities were increased significantly with BaP exposure in higher concentration. No statistical changes were observed in the effect of BaP exposure in different concentrations on CAT activities throughout the experiment.

The rationale and design of the CPCRA (Terry Beirn Community Programs for Clinical Research on AIDS) 058 FIRST (Flexible Initial Retrovirus Suppressive Therapies) trial

The CPCRA (Terry Beirn Community Programs for Clinical Research on AIDS) 058 FIRST (Flexible Initial Retrovirus Suppressive Therapies) trial is a large, long-term, randomized, prospective comparison of three different antiretroviral strategies in highly active antiretroviral therapy-naïve, HIV-1-infected persons. The trial was designed as a flexible framework upon which other studies could be added to answer more limited, but still important, questions. This article presents the study design, discusses the challenges we have faced in implementing the trial, and describes our preliminary experiences. Control Clin Trials 2001;22:176-190

[Establishment of EBV-immortalized lymphoblast cell lines from three Chinese Fanconi anemia patient and their subtyping]

OBJECTIVE

To establish EBV-immortalized lymphoblast cell lines from Chinese Fanconi anemia (FA) patients.

METHODS

The establishment of lymphoblast cell lines was by EBV-immortalization and subtyping of the cell lines by cell fusion, mytomycin C (MMC) inhibition analysis and/or immunoprecipitation and Western blot.

RESULT

(1) Three lymphoblast cell lines were established, two of them were sensitive to MMC with a IC (50) < 10 nmol/L. (2) The subtypes of all the three patients belong to FA-A group.

CONCLUSION

Complementation analysis was suitable for all FA patients with MMC-sensitive lymphoblastic cell lines, but this method is time consuming. Immunoprecipitation and Western blot are much faster for subtyping but could only be used for FA patients whose related genes had been cloned and specific antibodies been developed.

[A serological investigation of Legionella infection in eight-species of poultry and domestic animals in Sichuan province]

OBJECTIVE

To understand the prevalence rates of Legionella infection in poultries and domestic animals in Sichuan province.

METHODS

Serological investigation of antibodies against Legionella pneumophila serogroups 1 - 14 and Legionella micdadei was carried out, using microagglutination test (MAT) in eight species of poultries and domestic animals.

RESULTS

Infections with multiple serogroups were identified. However, each species had its own major serogroup with positive rates of different serogroups ranging from 0.83% to 59.18%. Positive rates of the poultry and domestic animals were accounted for 7.73% and 4.25% respectively.

CONCLUSION

It was suggested that poultries and domestic animals were widely infected with Legionella. It is important to carry out epidemiological surveillance in these domestic animals, poultries and environment for a better control program of this disease.

Evidence for Gal3p's cytoplasmic location and Gal80p's dual cytoplasmic-nuclear location implicates new mechanisms for controlling Gal4p activity in Saccharomyces cerevisiae

Genetics and in vitro studies have shown that the direct interaction between Gal3p and Gal80p plays a central role in galactose-dependent Gal4p-mediated GAL gene expression in the yeast Saccharomyces cerevisiae. Precisely how Gal3p-Gal80p interaction effects induction is not clear. It has been assumed that Gal3p interacts with Gal80p in the nucleus upon galactose addition to release Gal80p inhibition of Gal4p. Although Gal80p has been shown to possess nuclear localization signal (NLS) peptides, the subcellular distribution of neither Gal80p nor Gal3p was previously determined. Here we report that Gal3p is located in the cytoplasm and apparently excluded from the nucleus. We show that Gal80p is located in both the cytoplasm and the nucleus. Converting Gal80p into a nucleus-localized protein (NLS-Gal80p) by exogenous NLS addition impairs GAL gene induction. The impaired induction can be partially suppressed by targeting Gal3p to the nucleus (NLS-Gal3p). We document a very rapid association between NLS-Gal3p and Gal80p in vivo in response to galactose, illustrating that the nuclear import of Gal80p is very rapid and efficient. We also demonstrate that nucleus-localized NLS-Gal80p can move out of the nucleus and shuttle between nuclei in yeast heterokaryons. These results are the first indication that the subcellular distribution dynamics of the Gal3 and Gal80 proteins play a role in regulating Gal4p-mediated GAL gene expression in vivo.

Forming supramolecular networks from nanoscale rods in binary, phase-separating mixtures

Simulations show that when low-volume fractions of nanoscale rods are immersed in a binary, phase-separating blend, the rods self-assemble into needle-like, percolating networks. The interconnected network arises through the dynamic interplay of phase-separation between the fluids, through preferential adsorption of the minority component onto the mobile rods, and through rod-rod repulsion. Such cooperative effects provide a means of manipulating the motion of nanoscopic objects and directing their association into supramolecular structures. Increasing the rod concentration beyond the effective percolation threshold drives the system to self-assemble into a lamellar morphology, with layers of wetted rods alternating with layers of the majority-component fluid. This approach can potentially yield organic/inorganic composites that are ordered on nanometer scales and exhibit electrical or structural integrity.

Acute fatty liver of pregnancy: diagnosis and management of 8 cases

OBJECTIVE

To investigate the early recognition and management of acute fatty liver of pregnancy (AFLP) to improve maternal and fetal survival.

METHODS

Eight cases of AFLP seen in our hospital during the past three years were studied retrospectively. Symptoms, laboratory findings, timing of liver biopsy, and maternal and fetus outcome were assessed.

RESULTS

The mean gestational age at onset was 34 +/- 2 weeks. All cases were primigravida. In the early stages, all patients presented malaise, nausea, vomiting and epigastric distress followed by jaundice in the third trimester of pregnancy.

LABORATORY FINDINGS

all had raised transaminases and serum bilirubin (32.5-510.8 mumol/L), hypoalbuminemia (22.4-30.0 g/L), hypofibrinogenemia (< 180 mg/dl), prolonged prothrombin time and prolonged partial thromboplastin time. Maternal complication included hepatic encephalopathy (6 cases), ascites (6), hypoglycemia (5), hematemesis (2), and postpartum hemorrhage (5) and preeclampsia (4). Emergency cesarean section was performed in 3 cases. One mother died of fulminant hepatic failure and the others survived. There was no fetus death. Liver biopsy was done on the 5th to 15th postpartum day in 8 cases.

CONCLUSION

With increasing awareness, especially in the early recognition of milder cases, and prompt progressive management including early termination of pregnancy by cesarean section and large dose infusion of fresh frozen plasma and albumin alternately, the prognosis of AFLP can be improved.

[The recognition of the epidemic area of tsutsugamushi disease on Nan Peng Lie Island in China and the strategy of prevention]

OBJECTIVE

To investigate the region for the epidemic area of tsutsugamushi disease.

METHODS

Epidemiological studies, Orientia tsutsugamushi isolation, and preventive measures were used.

RESULTS

The region belonged to epidemic area of south subtropical zone. The main host was found Rattus norvegicu. The main biological vector was Leptotrombidium deliens. The seasonal trends of the quantity of Rattus norvegicu and Leptotrombidium deliens were consistent with the incidence change of the disease in the region. Orientia tsutsugamushi has been isolated from Rattus norvegicu and Leptotrombidium deliens. Data showed that Orientia tsutsugamushi isolated strains mainly belongs to Karp. Sero-epidemiological data showed that antibodies of Orientia tsutsugamushi are 100.0% positive in the residents of the region and 4.0% in army men. After taking comprehensive preventive measures, the incidence was descending.

CONCLUSION

Nan Peng Lie island was proved an epidemic area of tsutsugamushi disease.

NMR characterization of a pH-dependent equilibrium between two folded solution conformations of the pheromone-binding protein from Bombyx mori

NMR spectroscopic changes as a function of pH in solutions of the pheromone-binding protein of Bombyx mori (BmPBP) show that BmPBP undergoes a conformational transition between pH 4.9 and 6.0. At pH below 4.9 there is a single "acid form" (A), and a homogeneous "basic form" (B) exists at pH above 6.0. Between pH 5 and 6, BmPBP exists as a mixture of A and B in slow exchange on the NMR chemical shift time scale, with the transition midpoint at pH 5.4. The form B has a well-dispersed NMR spectrum, indicating that it represents a more structured, "closed" conformation than form A, which has a significantly narrower chemical shift dispersion. Conformational transitions of the kind observed here may explain heterogeneity reported for a variety of odorant-binding proteins, and it will be of interest to further investigate possible correlations with pH-dependent regulation of ligand binding and release in the biological function of this class of proteins.

[Detection of C gene mutation strain in vertical transmission of hepatitis B virus and its significance]

OBJECTIVE

This study aims at detecting C gene mutation strain in vertical transmission of hepatitis B virus (HBV).

METHODS

HBV C gene nt 2,022 - 2,321 was directly sequenced.

RESULTS

Homology of HBV nucleotide sequence and amino acid sequence in mothers, fathers and their fetus was 100%. Mutation of 2,189 and 2,288 nucleotide of C gene resulted in substitution at the 97th and 130th amino acids.

CONCLUSION

C gene mutation strain is present in vertical transmission of HBV. Presence of mutation strain may be the cause of failure in vaccination.

Disulfide structure of the pheromone binding protein from the silkworm moth, Bombyx mori

Disulfide bond formation is the only known posttranslational modification of insect pheromone binding proteins (PBPs). In the PBPs from moths (Lepidoptera), six cysteine residues are highly conserved at positions 19, 50, 54, 97, 108 and 117, but to date nothing is known about their respective linkage or redox status. We used a multiple approach of enzymatic digestion, chemical cleavage, partial reduction with Tris-(2-carboxyethyl)phosphine, followed by digestion with endoproteinase Lys-C to determine the disulfide connectivity in the PBP from Bombyx mori (BmPBP). Identification of the reaction products by on-line liquid chromatography-electrospray ionization mass spectrometry (LC/ESI-MS) and protein sequencing supported the assignment of disulfide bridges at Cys-19-Cys-54, Cys-50-Cys-108 and Cys-97-Cys-117. The disulfide linkages were identical in the protein obtained by periplasmic expression in Escherichia coli and in the native BmPBP.

[The role of spleen in induction and maintenance of anterior chamber-associated immune deviation in different species of animals]

PURPOSE

The importance of the spleen to the induction of anterior chamber-associated immune deviation (ACAID) in mice has been known for some time. Removal of the spleen within the first 4 days of injecting antigen into anterior chamber can abolish immune deviation and result in immunity. The purpose of this study is to explore the role of spleen in ACAID in other different species of animals.

METHODS

After splenectomy and sham-splenectomy, bovine serum albumin (BSA) as a soluble antigen was inoculated into the anterior chamber (AC) of different animals (rat, rabbit and monkey) respectively. Recipient animals were immunized with BSA and complete Freund's adjuvant. Delayed-type hypersensitivity (DTH) was assessed by skin challenge. The maintenance time of deviant immune response was evaluated in the fixed interval.

RESULTS

All the animals with receiving intraocular antigen inoculation, both in splenectomized group and in sham-splenectomized group, did not display DTH reaction. In addition, the maintenance time of immune deviation in both groups after AC inoculation of antigen was not significantly different. In contrast, all the animals without receiving intraocular antigen inoculation, both in splenectomized group and in sham-sple-nectomized group, displayed positive DTH reaction.

CONCLUSIONS

The spleen may not play an important role in the induction and maintenance of ACAID in rat, rabbit and monkey. These data suggest that as the evolution progresses, the function of spleen may be replaced by other lymphatic organs.

[HBV transmission from father to foetus and HBV DNA in tissues outside the liver]

OBJECTIVE

To study the possibility of HBV Transmission from father to foetus and HBV DNA in tissues outside liver.

METHODS

Paired sera were from 8 HBV man carriers whose wives were negative for HBVM and 8 foetuses who were infected with HBV in the womb. S gene nt 451-660 nucleotide, C gene nt 2,022-2,321 nucleotide were directly sequenced.

RESULTS

The homology of HBV sequence between father and foetus was very high. The mutations of 491, 494, 530, 546 and 581 nucleotide in the S gene caused 113, 114, 126, 131 and 143 amino acid substitution. HBV DNA can be detected in the tissues outside liver of foetus.

CONCLUSION

HBV transmission from father to foetus may be present. HBV DNA in tissues outside liver of foetus can be detected.

Kinetic model of phase separation in binary mixtures with hard mobile impurities

We develop a mean-field rate-equation model for the kinetics of phase separation in binary mixtures with hard mobile impurities. For impurities preferentially wet by one of the components, the phase separation is arrested in the late stage. The "steady-state" domain size depends strongly on both the particle diffusion constant and the particle concentration. We compare theoretical results with the simulation data and find good qualitative agreement.

Finite-volume lattice Boltzmann schemes in two and three dimensions

Simple and practical finite-volume schemes for the lattice Boltzmann equation are derived in two and three dimensions through the application of modern finite-volume methods. The schemes use a finite-volume vortex-type formulation based on quadrilateral elements in two dimensions and trilinear hexahedral elements in three dimensions. It is shown that the schemes are applicable to domains with irregular boundaries of arbitrary shape in two and three dimensions.

[Detection of S-gene mutation strain in vertical transmission of HBV and its significance]

OBJECTIVE

To study S-gene mutation of hepatitis B virus (HBV) in its vertical transmission and its significance.

METHODS

Nucleotides of S-gene NT451-660 of HBV were sequenced with dideoxy end termination technique in four female and six male carriers without HBV markers in their spouses and in their intrauterine infected fetuses.

RESULTS

It was showed that homology of HBV nucleotide and amino acid sequences in the mothers, fathers and their fetuses was very high. Mutation at the sites 491, 494, 530, 546 and 581 of S-gene resulted in amino acid substitution at the sites 113, 114, 126, 131 and 143, respectively. Mutations at the sites 126 were detected in two pairs of mother or father and her or his fetuses and mutations at the sites 131 in four fetuses, respectively, including combined mutation at the site 143 in two fetuses.

CONCLUSION

Strains with S-gene mutation, mainly at the sites 126, 131 and 143, could be found in HBV vertical transmissions, which could cause failure in HB vaccine immunization.

Evolution of vaginal Candida species recovered from human immunodeficiency virus-infected women receiving fluconazole prophylaxis: the emergence of Candida glabrata? Terry Beirn Community Programs for Clinical Research in AIDS (CPCRA)

The effect of fluconazole prophylaxis on the vaginal flora of 323 human immunodeficiency virus-infected women was evaluated in a multicenter, randomized, double-blind, placebo-controlled trial. Women with CD4 cell counts of < or = 300/mm3 received either 200 mg of fluconazole per week or placebo. Vaginal surveillance cultures were performed every 3 months. After a follow-up of 29 months, Candida albicans was recovered from 53% of patients receiving fluconazole and 68% of patients assigned placebo. Fluconazole was associated with a 50% reduction in the odds of being colonized with C. albicans but with higher rates for non-albicans Candida species. Candida glabrata was recovered from 40 women assigned fluconazole and 29 assigned placebo (relative odds, 1.96; 95% confidence interval, 0.98-3.94). Fluconazole had an early and persistent effect on the vaginal mycoflora, with the emergence of C. glabrata vaginal colonization within the first 6 months. The effect of fluconazole prophylaxis can be attributed to the reduction in vaginal C. albicans colonization; however, C. glabrata colonization rapidly supervened.

Co-infection with opportunistic pathogens promotes human immunodeficiency virus type 1 infection in macrophages

Human immunodeficiency virus type 1 (HIV-1) infection is dependent on susceptible host cells that express both CD4 and chemokine co-receptors. The co-receptor CCR5 is associated with primary infection by macrophage-tropic virus isolates, whereas CXCR4 is commonly associated with T cell- and dual-tropic viruses. Once infected, lymphocytes and macrophages may replicate HIV-1 or harbor latent virus, depending on environmental factors and cellular activation. Immune activation is often associated with viremia, which is consistent with enhanced infection and viral replication in activated cells harboring virus. In this regard, opportunistic infections activate the immune system with the detrimental sequelae of enhanced viral replication and viremia. Under these conditions, viral expansion extends beyond T cells to tissue macrophages, many of which are co-infected with opportunistic pathogens. The opportunistic infections promote macrophage susceptibility to HIV-1 through cytokine modulation and altered chemokine co-receptors, potential targets for intervention.

Finite-volume lattice Boltzmann method

We present a finite-volume formulation for the lattice Boltzmann method (FVLBM) based on standard bilinear quadrilateral elements in two dimensions. The accuracy of this scheme is demonstrated by comparing the velocity field with the analytical solution of the Navier-Stokes equations for time dependent rotating Couette flow and Taylor vortex flow. To demonstrate the flexibility of the scheme, we have also simulated a modified rotating Couette flow, where the inner cylinder has an elliptical shape. The results agree with those obtained from the traditional marker-and-cell method. The FVLBM scheme is applicable to arbitrarily shaped two-dimensional regions, and thus the range of applicability of the lattice Boltzmann method has been significantly extended.

Loss of anterior chamber-associated immune deviation during normal pregnancy in primates

PURPOSE

We recently found that loss of anterior chamber-associated immune deviation was associated with normal pregnancy in rabbits. The purpose of this study is to further investigate whether the same events occurred in nonhuman primates.

METHODS

Mid-pregnant cynomolgus monkeys were randomly selected. Bovine serum albumin (BSA) was inoculated in anterior chamber of eyes of nonpregnant and mid-pregnant monkeys that were subsequently immunized with BSA in adjuvant. Delayed-type hypersensitivity (DTH) was assessed by skin challenge.

RESULTS

Non-pregnant monkeys of intracameral BSA proved able to acquire antigen-specific suppression of delayed-type hypersensitivity. By contrast, inoculation of BSA to anterior chamber of pregnant monkeys abolished the DTH-suppression effect.

CONCLUSIONS

This is the first demonstration in primates that loss of anterior chamber-associated immune deviation occurred during normal pregnancy. The fluctuations of systemic hormone levels during normal pregnancy might influence local immunoregulation within the eye.