Identification of a locus characteristic of male individuals of buffalo grass [Buchloe dactyloides (Nutt.) Engelm.] by using an RAPD marker

Buffalo grass [Buchloe dactyloides (Nutt.) Engelm.] plants can be either male, female, or hermaphrodite (monoecious). As there is no morphological difference in the early vegetative growth of these three classes of plants, it is worthwhile to use molecular biological methods to attempt to identify the sex of a plant at this early growth period. In this study, we identified 23 plants that had a stable sex for over at least 3 years. Of these, 9 were male plants, 10 were female plants, and 4 were hermaphrodites. Screening of 300 RAPD primers identified a primer, namely S211 (5'-ttccccgcga-3'), which is capable of identifying male plants. The specific fragment was cloned, sequenced, and submitted to the GenBank database (accession No. JN982469). When used to identify the sex of 188 plants during their first growing season, the S211 primer correctly identified 85.8% of all male plants. Our results showed that the S211 primer can identify the male, and in doing so, it facilitates buffalo grass breeding work.

Long PCR-RFLP of 16S-ITS-23S rRNA genes: a high-resolution molecular tool for bacterial genotyping

AIMS

To perform a systematic evaluation of the applicability, validity and reliability of the long PCR-RFLP of 16S-ITS-23S rRNA genes for bacterial genotyping using both sequences retrieved from public genome databases and the experimental data obtained on bacterial cultures.

METHODS AND RESULTS

3301 Full-length sequences of 16S-ITS-23S rRNA genes were retrieved from 885 published bacterial genomes. Copy numbers of the whole set of 16S-ITS-23S rRNA genes per genome ranged from 1 (n = 161) to 14 (n = 4) with an average of 3.71. Their length varied greatly, from 4319 to 6568 bp with an average of 4952 bp. Computer-simulated RFLP analyses of the 16S-ITS-23S fragments flanked by the conserved primers 27F and 2241R suggested MspI, RsaI, HhaI and TaqI as the most appropriate enzymes for long PCR-RFLP analysis of the 16S-ITS-23S sequence. MspI was used to screen over 900 bacterial cultures isolated from the Huguangyan Maar Lake in southern China. An experimental sequencing of 16S rRNA genes of the isolates possessing a unique RFLP band pattern proved the broad applicability and high resolution of this approach.

CONCLUSIONS

These results indicate that long PCR-RFLP of 16S-ITS-23S rRNA genes is a potentially universal and reliable bacterial genotyping tool with a high resolution.

SIGNIFICANCE AND IMPACT OF THE STUDY

The methodology of long PCR-RFLP of 16S-ITS-23S rRNA genes will facilitate the exploration and tracing of cultivable microbial diversity in natural environments.

Pineal parenchymal tumours: minimum apparent diffusion coefficient in prediction of tumour grading

Retrospective assessment was performed of the minimum apparent diffusion coefficient (minADC) together with quantitative assessment of the histopathological features of resected tumour tissue and the Ki-67 labelling index (LI) for predicting pineal parenchymal tumour (PPT) grade. Magnetic resonance images of tumours from 26 male and female patients (mean age 27.7 years) with pathologically confirmed PPTs, comprising 10 pineocytomas (PCs), seven pineal parenchymal tumours of intermediate differentiation (PPTIDs) and nine pineoblastomas (PBs), were reviewed retrospectively. Using ADC maps derived from isotropic diffusion-weighted images, the minADC value of each tumour was determined postoperatively from several regions of interest defined in the tumour, excluding cystic, necrotic, haemorrhagic or calcified components. Surgical intervention was undertaken in all cases. The Ki-67 LI was measured in surgical specimens. Mean minADC and Ki-67 LI showed significant differences among PCs, PPTIDs and PBs, and minADC was negatively correlated with Ki-67 LI. It is concluded that the minADC of PPTs provide useful additional information when predicting tumour grading.

Value of Diffusion-Weighted Imaging in Grading Tumours Localized in the Fourth Ventricle Region by Visual and Quantitative Assessments

This study investigated visual and quantitative assessment of diffusion-weighted imaging (DWI) for grading tumours localized in the fourth ventricle region. Patients were diagnosed histopathologically and classified into two groups: those with high-grade (World Health Organization [WHO] grades III and IV) and those with low-grade tumours (benign, WHO grades I and II). DWI signal intensity was described using a five-point scale. Minimum apparent diffusion coefficient (ADC) values were obtained from areas with the lowest signal. The mean signal intensity was significantly higher in high-grade than in low-grade tumours. The mean minimum ADC value was significantly lower in high-grade than low-grade tumours. Marked hyperintensity had sensitivity, specificity, positive predictive value and negative predictive value of 89.7%, 100%, 100% and 94.2%, respectively, when used as a diagnostic tool for high-grade tumours compared with 96.6%, 97.9%, 96.6% and 97.9%, respectively, when using a minimum ADC of 0.9 × 10−3 mm2/s as a diagnostic marker. It was concluded that DWI is helpful in predicting the grades of tumours in the fourth ventricle region.

Unfavorable prognosis of elderly patients with early-stage extranodal nasal-type NK/T-cell lymphoma

BACKGROUND

Extranodal nasal-type NK (natural killer)/T-cell lymphoma in elderly patients is rare, and its prognosis is unclear. This study aims to investigate the clinical characteristics and prognosis of this lymphoma.

PATIENTS AND METHODS

We analyzed 24 patients (age, >60 years old) with early-stage extranodal nasal-type NK/T-cell lymphoma. Among these patients, 23 received radiotherapy alone (n = 15) or radiotherapy and chemotherapy (n = 8) and 1 received chemotherapy alone.

RESULTS

Elderly patients with early-stage extranodal nasal-type NK/T-cell lymphoma were characterized by male predominance, good performance, large proportion of localized disease, more comorbidities, low-risk international prognostic index, and unfavorable prognosis. The 5-year cancer-specific survival (CSS), overall survival (OS), and progression-free survival (PFS) rates for all patients were 54.3%, 42.0%, and 40.2%, respectively. The 5-year CSS, OS, and PFS rates were 43.5%, 36.6%, and 34.1% in patients who received radiotherapy alone, and 50%, 50%, and 50% in patients who received radiotherapy and chemotherapy, respectively (P = 0.852 for CSS, P = 0.801 for OS, and P = 0.694 for PFS). Four patients died of treatment-related mortality.

CONCLUSION

Elderly patients with early-stage extranodal nasal-type NK/T-cell lymphoma exhibit poor prognosis and need special attention because of high treatment-related mortality.

Measurements of h(c)(1P(1)) in psi' decays

We present measurements of the charmonium state h(c)(1P(1)) made with 106x10(6) psi' events collected by BESIII at BEPCII. Clear signals are observed for psi'-->pi0 h(c) with and without the subsequent radiative decay h(c)-->gamma eta(c). First measurements of the absolute branching ratios B(psi'-->pi0 h(c)) = (8.4+/-1.3+/-1.0) x 10(-4) and B(h(c)-->gamma eta(c)) = (54.3+/-6.7+/-5.2)% are presented. A statistics-limited determination of the previously unmeasured h(c) width leads to an upper limit Gamma(h(c))<1.44 MeV (90% confidence). Measurements of M(h(c)) = 3525.40+/-0.13+/-0.18 MeV/c2 and B(psi'-->pi0 h(c)) x B(h(c)-->gamma eta(c)) = (4.58+/-0.40+/-0.50) x 10(-4) are consistent with previous results.

Primary myxoid liposarcoma of the thyroid gland

Primary myxoid liposarcoma of the thyroid gland is extremely rare. This report describes such a case. A 59-year-old woman was admitted for evaluation of a 6 x 6 x 5 cm nodule in the left lobe of the thyroid gland. Left thyroid lobectomy was performed without any postoperative treatment except for follow-up. Osseous and pulmonary metastasis developed 1 year later and the patient died 15 months after the surgery. The clinical course and treatment choice are discussed.

SEPPA: a computational server for spatial epitope prediction of protein antigens

In recent years, a lot of efforts have been made in conformational epitope prediction as antigen proteins usually bind antibodies with an assembly of sequentially discontinuous and structurally compact surface residues. Currently, only a few methods for spatial epitope prediction are available with focus on single residue propensity scales or continual segments clustering. In the method of SEPPA, a concept of ‘unit patch of residue triangle’ was introduced to better describe the local spatial context in protein surface. Besides that, SEPPA incorporated clustering coefficient to describe the spatial compactness of surface residues. Validated by independent testing datasets, SEPPA gave an average AUC value over 0.742 and produced a successful pick-up rate of 96.64%. Comparing with peers, SEPPA shows significant improvement over other popular methods like CEP, DiscoTope and BEpro. In addition, the threshold scores for certain accuracy, sensitivity and specificity are provided online to give the confidence level of the spatial epitope identification. The web server can be accessed at http://lifecenter.sgst.cn/seppa/index.php. Batch query is supported.

Electronic structure and magnetic properties of Co-doped CeO(2): based on first principle calculation

The electronic structure and magnetic properties of Co-doped CeO(2) are theoretically investigated by first principles calculations based on the density functional theory + U (DFT+U) methods, using the WIEN2k package. With the presence of oxygen vacancies (V(O)) in CeO(2), d and f orbits of Ce are obviously pulled closer to the Fermi level, but without spin polarization. On the other hand, in Co-doped CeO(2), V(O) defects can lead to strong ferromagnetic coupling between the nearest neighboring Co ions. Such ferromagnetic exchange coupling is mainly attributed to spin splitting of Co 3d states, via electrons trapped in V(O). The results provide direct evidence for the F-center mediated exchange interaction in oxide-based magnetic semiconductors.

Though with constraints imposed by endosymbiosis, preferential attachment is still a plausible mechanism responsible for the evolution of the chloroplast metabolic network

Chloroplasts evolved as a result of endosymbiosis, during which sophisticated mechanisms evolved to translocate nucleus-encoded plastid-targeted enzymes into the chloroplast to form the chloroplast metabolic network. Given the constraints and complexity of endosymbiosis, will preferential attachment still be a plausible mechanism for chloroplast metabolic network evolution? We answer this question by analysing the metabolic network properties of the chloroplast and a cyanobacterium, Synechococcus sp. WH8102 (syw). First, we found that enzymes related to more ancient pathways are more connected, and synthetases have the highest connectivity. Most of the enzymes shared by the two densest cores between the chloroplast and syw are synthetases. Second, the highly conserved functional modules mainly consist of highly connected enzymes. Finally, isozymes and enzymes from endosymbiotic gene transfer (EGT) were distributed mainly in conserved modules and showed higher connectivity than nonisozymes or non-EGT enzymes. These results suggest that even with severe evolutionary constraints imposed by endosymbiosis, preferential attachment is still a plausible mechanism responsible for the evolution of the chloroplast metabolic network. However, the current analysis may not completely differentiate whether the chloroplast network properties reflect the evolution of the chloroplast network through preferential attachment or has been inherited from its cyanobacterial ancestor. To fully differentiate these two possibilities, further analyses of the metabolic network structure properties of organisms at various intermediate evolutionary stages between cyanobacteria and the chloroplast are needed.

Effect of Bt cotton expressing Cry1Ac and Cry2Ab, non-Bt cotton and starvation on survival and development of Trichoplusia ni (Lepidoptera: Noctuidae)

Effects of Bollgard II cotton containing two Bacillus thuringensis var. kurstaki Berliner (Bt) toxin proteins (Cry1Ac and Cry2Ab), non-Bt cotton (DPL 491) and starvation on survival and development of cabbage looper, Trichoplusia ni (Hübner), were determined in the laboratory. Larvae of the first four larval instars died when they fed on the terminal leaves of Bt cotton plants at 50 days after planting (DAP). However, 51.3% of fifth instars that fed on 50 DAP Bt cotton leaves pupated, and 87.1% of the pupae successfully developed into adults. Of the unfed fifth instars (starved), 55.6% pupated and 88.1% of the pupae emerged. Pupae that developed from larvae fed on Bt cotton leaves and unfed were significantly smaller, being 89.7 and 73.2% of the weight of the pupae that developed from larvae fed on non-Bt cotton leaves. Leaves of 120 DAP Bt cotton were less toxic to T. ni larvae. When the first instars continuously fed on 120 DAP Bt cotton leaves, 75.9, 60.6, 56.4 and 38.4% of larvae survived to second, third, fourth and fifth instars respectively, and 20.9% pupated and 17.9% successfully became adults. However, it took the surviving first instars 37.1 days to become adults, which was 7.2 and 8.9 days longer than those fed on 50 and 120 DAP non-Bt cottons respectively. Pupae that developed from larvae that fed on 120 DAP Bt cotton leaves were only 50.9 and 52.6% of the weight of those developed from larvae that fed on 50 and 120 DAP non-Bt cotton respectively. Non-Bt cotton, both 50 and 120 DAP, did not exhibit significant effects on larval survival and development, except that the pupae in the 50 DAP non-Bt cotton treatments developed over a significantly longer time than those in the 120 DAP non-Bt cotton treatment.

A simple method for extracting C-phycocyanin from Spirulina platensis using Klebsiella pneumoniae

C-phycocyanin (C-PC) was extracted from fresh Spirulina platensis by deploying a species of non-pathogenic nitrogen-fixing bacteria, namely, Klebsiella pneumoniae. The algal slurry was neither washed nor centrifuged; the bacterial culture was poured into the slurry, the vessel sealed, and crude C-PC extracted after about 24 h. The extraction was clean and efficient, and the purity and concentration of C-PC proved to be of adequate quality.

Computer prediction of cardiovascular and hematological agents by statistical learning methods

Computational methods have been explored for predicting agents that produce therapeutic or adverse effects in cardiovascular and hematological systems. The quantitative structure-activity relationship (QSAR) method is the first statistical learning methods successfully used for predicting various classes of cardiovascular and hematological agents. In recent years, more sophisticated statistical learning methods have been explored for predicting cardiovascular and hematological agents particularly those of diverse structures that might not be straightforwardly modelled by single QSAR models. These methods include partial least squares, multiple linear regressions, linear discriminant analysis, k-nearest neighbour, artificial neural networks and support vector machines. Their application potential has been exhibited in the prediction of various classes of cardiovascular and hematological agents including 1, 4-dihydropyridine calcium channel antagonists, angiotensin converting enzyme inhibitors, thrombin inhibitors, AchE inhibitors, HERG potassium channel inhibitors and blockers, potassium channel openers, platelet aggregation inhibitors, protein kinase inhibitors, dopamine antagonists and torsade de pointes causing agents. This article reviews the strategies, current progresses and problems in using statistical learning methods for predicting cardiovascular and hematological agents. It also evaluates algorithms for properly representing and extracting the structural and physicochemical properties of compounds relevant to the prediction of cardiovascular and hematological agents.

[Epidemic situation analysis of Japanese encephalitis in 2005.]

BACKGROUND

To investigate the epidemic situation of Japanese encephalitis (JE) in three provinces, Guizhou, Sichuan, and Hubei in 2005.

METHODS

Information about epidemic situation of JE, mosquitoes specimens were collected and titers of JE virus in hosts in the above three surveillance sites were determined.

RESULTS

The reported cases of JE in Guizhou, Sichuan, and Hubei province accounted for 40.7% of total cases in 2005 in China. The numbers of cases in Guizhou and Sichuan ranked at the first two in China, morbidity exceeded 1/100,000, which was higher than average level in China. Zero to 10 years old children accounted for 90% in reported cases. Most of the cases were children lived at home. Almost all JE cases were presented from June to September, but most cases were reported between July and August. Investigaton of the density of vector showed that the dominant mosquitoes were Culex, especially the Culex tritaeniorhynchus.

CONCLUSION

The epidemic status of JE was similar among the three provinces and the whole country. The number of JEV cases in Guizhou and Sichuan were the highest in China.

Stochastic phase dynamics: multiscale behavior and coherence measures

A multiscale approach is used to derive stochastic amplitude and phase dynamics for a canonical noise-sensitive model exhibiting coherence resonance. Explicit expressions for the dependence on noise levels and model type are compared with computational coherence measures.

Monitoring of diamondback moth (Lepidoptera: Plutellidae) resistance to spinosad, indoxacarb, and emamectin benzoate

Six to nine populations of the diamondback moth, Plutella xylostella (L.), were collected annually from fields of crucifer vegetables in the United States and Mexico from 2001 to 2004 for baseline susceptibility tests and resistance monitoring to spinosad, indoxacarb, and emamectin benzoate. A discriminating concentration for resistance monitoring to indoxacarb and emamectin benzoate was determined based on baseline data in 2001 and was used in the diagnostic assay for each population in 2002-2004 together with a discriminating concentration for spinosad determined previously. Most populations were susceptible to all three insecticides, but a population from Hawaii in 2003 showed high levels of resistance to indoxacarb. Instances of resistance to spinosad occurred in Hawaii (2000), Georgia (2001), and California (2002) as a consequence of a few years of extensive applications in each region. The collaborative monitoring program between university and industry scientists we discuss in this article has provided useful information to both parties as well as growers who use the products. These studies provide a baseline for developing a more effective resistance management program for diamondback moth.

Monitoring of diamondback moth (Lepidoptera: Plutellidae) resistance to spinosad, indoxacarb, and emamectin benzoate

Six to nine populations of the diamondback moth, Plutella xylostella (L.), were collected annually from fields of crucifer vegetables in the United States and Mexico from 2001 to 2004 for baseline susceptibility tests and resistance monitoring to spinosad, indoxacarb, and emamectin benzoate. A discriminating concentration for resistance monitoring to indoxacarb and emamectin benzoate was determined based on baseline data in 2001 and was used in the diagnostic assay for each population in 2002-2004 together with a discriminating concentration for spinosad determined previously. Most populations were susceptible to all three insecticides, but a population from Hawaii in 2003 showed high levels of resistance to indoxacarb. Instances of resistance to spinosad occurred in Hawaii (2000), Georgia (2001), and California (2002) as a consequence of a few years of extensive applications in each region. The collaborative monitoring program between university and industry scientists we discuss in this article has provided useful information to both parties as well as growers who use the products. These studies provide a baseline for developing a more effective resistance management program for diamondback moth.

Preparation and in vitro and in vivo release studies of Huperzine A loaded microspheres for the treatment of Alzheimer's disease

The purpose of this study was to prepare microspheres containing Huperzine A, which is used for patients suffering from Alzheimer's disease because of its potent anticholineestase activity, and to clarify in vitro and in vivo release characteristics of them. The preparation and in vitro and in vivo release studies of Huperzine A loaded microspheres were described. By spray drying method, Huperzine A was encapsulated successfully in the microspheres which were spherical with a non-porous and smooth surface. In vitro studies showed that the release of Huperzine A from microspheres was depended on the properties of polymers and the release medium. Counter-ionic interaction between the primary amine group of Huperzine A and the carboxylic terminal group of PLG polymers improves the encapsulation of Huperzine A, reducing the initial burst and extending the sustained release. High molecular weight of PLG polymer leads to a negative influence on sustained release of Huperzine A due to less carboxylic terminal groups. Acidic medium also reduces the initial burst and sustained the release due to decreased swelling of the polymeric matrix. In vivo experiment showed, after intramuscular injection, that the plasma concentration of Huperzine A reached the max. at 2 h, then fell rapidly to a stable and near constant level of 0.5 to 2.5 ng/ml within 2 weeks, until the drug was exhausted from the microspheres. It indicates the potential of a 2-week sustained release system of Huperzine A.

An autosomal genomic scan for loci linked to type 2 diabetes in northern Han Chinese

We report the results of a genome-wide scan conducted in 219 individuals from 34 large multiplex nuclear pedigrees from the northern Han Chinese population at an average resolution of about 10 cM. Nonparametric two-point and multipoint linkage analyses were performed to detect evidence of linkage with type 2 diabetes in this study. On chromosome 1 four regions showed evidence of linkage with type 2 diabetes in northern Han Chinese. Of these regions a marker D1S193 (73 cM) showed evidence of linkage (two-point nonparametric linkage 2.409), and another region (around 190 cM) was a replication of several other studies performed in different ethnic populations. Evidences of linkage have been confirmed by typing additional markers (average distance 1-5 cM) flanking these two positive regions on chromosome 1. We also found indication of linkage with type 2 diabetes on chromosomes 2, 10, 12, 18, 20, and 22 by two-point linkage analyses.

MgO nanowire growth from Mg metal and SiO2

Comparative study on the diameter distribution of MgO nanowires has been carried out. MgO nanowires could be synthesized by the direct reaction between metallic magnesium and silica, and the obtained nanowires have diameters ranging from 50 to 200 nm and lengths of several hundreds nanometers, exhibiting a straight wire. The diameter can be downscaled to smaller than 50 nm, and the nanowire exhibits a curved and twisted one-dimensional structure with lengths up to several micrometers, when a fine support catalyst was used as the reactant. The diameter-controlled growth mechanism was also explained in this work.

In vitro mutagenesis of Xanthomonas campestris alpha-amylase gene by partially replacing deoxythymidine triphosphate with 5-bromo-2'-deoxyuridine-5'-triphosphate using a PCR technique

Three mutants of the wild type alpha-amylase gene from Xanthomonas campestris pv. campestris 8004 were obtained using a PCR technique in which deoxythymidine triphosphate (dTTP) was partially replaced by 5-bromo-2'-deoxyuridine-5'-triphosphate (BrdUTP), at an optimal dTTP:BrdUTP ratio of 1000:1. Of thre three mutants that were obtained and which were sequenced, one mutant with 40 times higher activity than the wild type alpha-amylase gene product was obtained by using primary PCR products as a template for a second PCR reaction.

Analysis of Cx43alpha1 promoter function in the developing zebrafish embryo

The Cx43alpha1 gap junctions play an important role in cardiovascular development. Studies using transgenic mouse models have indicated that this involves an essential role for Cx43alpha1 in modulating neural crest cell motility. We previously showed that a 6.8 kb mouse genomic sequence containing the promoter and upstream regulatory sequences of the Cx43alpha1 gene can drive lacZ reporter gene expression in all neural crest cell lineages in the mouse embryo. To obtain further insights into the sequence motifs and regulatory pathways involved in targeting Cx43alpha1 gene expression in neural crest cells, we assayed the activity of the mouse Cx43alpha1 promoter in evolutionarily distantly related zebrafish embryos. For these studies, the 6.8kb Cx43alpha1 genomic sequence and various deletion derivatives were used to generate GFP or lacZ expression vectors. The transcriptional activities of these constructs were analyzed in vivo after microinjection into one- or two- cell stage zebrafish embryos. These studies indicated that the mouse Cx43alpha1 promoter can drive lacZ expression in neural crest cells in the zebrafish embryos. Analysis by whole mount in situ hybridization showed that the endogenous zebrafish Cx43alpha1 gene is expressed maternally and zygotically, and expression is observed in regions where neural crest cells are found. To further elucidate the developmental regulation of Cx43alpha1 gene expression, we screened a zebrafish BAC library and identified a clone containing the entire zebrafish Cx43alpha1 gene and flanking upstream and downstream sequences. The upstrean Cx43alpha1 promoter sequences from zebrafish, mouse, and human were analyzed for evolutionarily conserved DNA motifs. Overall these studies suggest that the sequence motifs and transcriptional regulation involved in the targeting Cx43alpha1 expression to neural crest cells are evolutionarily conserved in zebrafish and mouse embryos.

Identification of bulb from Fritillaria cirrhosa by PCR with specific primers

Bulb of Fritillaria cirrhosa is an important traditional Chinese herbal medicine. According to the Chinese Pharmacopoeia (1995), it is commonly used as an antitussive and expectorant. Many young bulbs from species of Fritillaria are similar to those of F. cirrhosa, but they are different in price and quality. Therefore, there are many young bulbs from species of Fritillaria that could fake those of F. cirrhosa on the commercial market. The coding region of 5S-rRNA is highly conserved in higher eukaryotes. The 5S-rRNA spacer region sequences of F. thunbergii, F. pallidiflora, F. ussuriensi, F. delavayi, F.cirrhosa, F. anhuiensis, F. puqiensis were cloned by PCR with a pair of primers located within the conserved coding region. Based on sequences analyses of the 5S-rRNA spacer region from the 7 species, a specific sequence was found in F. cirrhosa. A pair of specific primers was designed for differentiating the bulbs of F. cirrhosa from each other by PCR. This result indicated that the method is rapid, more accurate and applicable in identification of the bulbs of F. cirrhosa at the DNA level.

[Performance analysis of methods that predict transmembrane regions]

The increasing protein sequences from the genome project require the oretical methods to predict transmembrane regions. Evaluation of these prediction methods will not only help biologists to select appropriate methods, but also provide bioinformatian guidance to develop new methods. In this work, the latest membrane protein topology database was used as the test set and selected soluble proteins was used as control. The analyses of performance of published online prediction methods are presented. Results show that HMMTOP (2.0) has the best performance among current methods.

Monitoring and characterization of diamondback moth (Lepidoptera: Plutellidae) resistance to spinosad

Fourteen populations of the diamondback moth, Plutella xylostella (L.), were collected from fields of crucifer vegetables in the United States, Mexico, and Thailand in 1999 and 2000 for susceptibility tests with spinosad. Most populations were susceptible to spinosad and similar to earlier baseline values, but populations from Thailand and Hawaii showed high levels of tolerance. A statewide survey in Hawaii in 2000 and 2001 indicated resistance problems on several islands. One colony collected in October 2000 from Pearl City, HI, was subjected to further selection pressure, using spinosad in the laboratory, and then was used as the resistant strain (Pearl-Sel) for other tests. Spray tests using the recommended field rates of spinosad on potted broccoli plants in the greenhouse confirmed that field control failures due to resistance were possible in the areas of these collections. Analysis of probit lines from F1 reciprocal crosses between the Pearl-Sel and S strain indicated that resistance to spinosad was inherited autosomally and was incompletely recessive. A direct test of monogenic inheritance based on the F1 x Pearl-Sel backcrosses suggested that resistance to spinosad was probably controlled by one locus. The synergists S,S,S-tributyl phosphorotrithioate and piperonyl butoxide did not enhance the toxicity of spinosad to the resistant colony, indicating metabolic mediated detoxification was probably not responsible for the spinosad resistance. Two field colonies in Hawaii that were resistant to spinosad were not cross-resistant to emamectin benzoate or indoxacarb. Resistance developed in Hawaii due to the continuous cultivation of crucifers in which as many as 50 applications of spinosad per year may have been made to a common population of P. xylostella in sequential plantings, although each grower might have used the labeled restrictions for resistance management. Resistance management strategies will need to address such cropping and pest management practices.

Differential induction of brain-derived neurotrophic factor mRNA in rat inferior olive subregions following unilateral labyrinthectomy

Vestibular compensation, the neuronal process underlying behavioral recovery from vestibular dysfunction produced by unilateral labyrinthectomy, is attributed to functional reorganization of neuronal circuits in the brainstem and cerebellum. Climbing fibers originating from the inferior olive are suggested to play a crucial role in this compensatory process. To assess the possible contribution of brain-derived neurotrophic factor (BDNF) to the function of climbing fibers during vestibular compensation, we investigated the BDNF mRNA expression in the rat inferior olive after unilateral labyrinthectomy by quantitative in situ hybridization. We found several induction patterns depending on the subregions of the inferior olive 6 h after unilateral labyrinthectomy. First, in the dorsal cap and the ventrolateral outgrowth, the expression levels increased on the side contralateral to the lesion and decreased on the ipsilateral side. Second, in the beta nucleus, C subnucleus of the medial accessory olive, and A/B subnuclei of the medial accessory olive, we detected an increase in the mRNA expression level on the side contralateral to the lesion, but no changes in the expression level on the ipsilateral side. In the beta nucleus, where the strongest induction was observed, the mRNA expression level increased nearly five-fold. Third, in the dorsomedial cell column, the mRNA expression levels increased on both sides. Finally, we did not detect significant changes in mRNA expression levels in the other subregions of the inferior olive, the dorsal accessory olive, principal olive and rostral medial accessory olive. The changes in BDNF mRNA expression reverted to control levels by 72 h after the labyrinthectomy. The inferior olive subregions that showed changes in BDNF mRNA expression levels send climbing fibers to the cerebellar cortical regions that, in turn, project to the vestibular nuclei. Therefore, BDNF induced in these subregions could contribute to the functional reorganization of the olivo-cerebellar system for vestibular control.

Different cross-resistance patterns in the diamondback moth (Lepidoptera: Plutellidae) resistant to Bacillus thuringiensis toxin Cry1C

Two strains of the diamondback moth, Plutella xylostella (L.), were selected using Cry1C protoxin and transgenic broccoli plants expressing a Cry1C toxin of Bacillus thuringiensis (Bt). Both strains were resistant to Cry1C but had different cross-resistance patterns. We used 12 Bt protoxins for cross-resistance tests, including Cry1Aa, Cry1Ab, Cry1Ac, Cry1Bb, Cry1C, Cry1D, Cry1E, Cry1F, Cry1J, Cry2Ab, Cry9Aa, and Cry9C. Compared with the unselected sister strain (BCS), the resistance ratio (BR) of one strain (BCS-Cry1C-1) to the Cry1C protoxin was 1,090-fold with high level of cross-resistance to Cry1Aa, Cry1Ab, Cry1Ac, Cry1F, and Cry1J (RR > 390-fold). The cross-resistance to Cry1A, Cry1F, and Cry1J in this strain was probably related to the Cry1A resistance gene(s) that came from the initial field population and was caused by intensive sprayings of Bt products containing Cry1A protoxins. The neonates of this strain can survive on transgenic broccoli plants expressing either Cry1Ac or Cry1C toxins. The other strain (BCS-Cry1C-2) was highly resistant to Cry1C but not cross-resistant to other Bt protoxins. The neonates of this strain can survive on transgenic broccoli expressing Cry1C toxin but not Cry1Ac toxin. The gene(s) conferring resistance to Cry1C segregates independently from Cry1Ac resistance in these strains. The toxicity of Cry1E and Cry2Ab protoxins was low to all of the three strains. The overall progress of all work has resulted in a unique model system to test the stacked genes strategy for resistance management of Bt transgenic crops.

Paradoxical role of large-conductance calcium-activated K+ (BK) channels in controlling action potential-driven Ca2+ entry in anterior pituitary cells

Activation of high-conductance Ca(2+)-activated K(+) (BK) channels normally limits action potential duration and the associated voltage-gated Ca(2+) entry by facilitating membrane repolarization. Here we report that BK channel activation in rat pituitary somatotrophs prolongs membrane depolarization, leading to the generation of plateau-bursting activity and facilitated Ca(2+) entry. Such a paradoxical role of BK channels is determined by their rapid activation by domain Ca(2+), which truncates the action potential amplitude and thereby limits the participation of delayed rectifying K(+) channels during membrane repolarization. Conversely, pituitary gonadotrophs express relatively few BK channels and fire single spikes with a low capacity to promote Ca(2+) entry, whereas an elevation in BK current expression in a gonadotroph model system leads to the generation of plateau-bursting activity and high-amplitude Ca(2+) transients.

[A study on breeding of "Ganzaoxian 47" from dry seeds of rice carried by recoverable satellite]

OBJECTIVE

To observe and investigate the variation and heredity of the offspring of dry seeds of rice carried by satellite, hence to select early maturing mutants, and to cultivate directly "Ganzaoxian 47" new varieties for production application. Isozymes analyses and studies of the new varieties and its original CK varieties were made.

METHOD

Dry seeds of rice restorer line were carried to the space on board a recoverable satellite for 7 d in 1992. After recovery the seeds were planted in the field to study the agricultural characters, yield, disease resistance, rice quality and peroxidase isozymes change.

RESULT

Its agricultural characters, yield, disease resistance, rice quality and peroxidase isozymes all showed distinct changes, and new varieties were cultivate directively for production application.

CONCLUSION

It could be considered that certain variations of the rice seeds induced by the space conditions were heritable to the offspring's, and directive cultivation of new varieties is possible for production application. It could be used as a new method for mutagenic seed breeding.

Glutamine enhances the gut-trophic effect of growth hormone in rat after massive small bowel resection

Background. Bowel-specific nutrient, glutamine, growth hormone, and modified diet have been reported to jointly improve nutrient absorption in patients with short bowel syndrome. However, controversy exists about the exact treatment factor. In this study we attempted to analyze the individual and combined effect of glutamine supplementation and growth hormone on small bowel adaptation by using tube feeding to control luminal nutrition supply. Materials and methods. Thirty-two adult male Sprague-Dawley rats (278 +/- 8 g) underwent 85% mid-small bowel resection and were randomly assigned to four groups: Control, receiving control liquid diet via a gastrotomy tube; GLN, receiving liquid diet enriched with 20 g. L(-1) glutamine; GH, receiving subcutaneous growth hormone (GH) (0.3 IU, bid); and GLN + GH, receiving both glutamine supplementation and GH treatment. All animals were provided with isocaloric (60 kcal/day) and isonitrogenous (0.686 g/day) nutrition. Absorption tests were performed in the form of oral nutrient tests with (14)C-labeled glucose and (3)H-labeled palmitic acid on the Postoperative Day 12. Results. GH treatment significantly increased the plasma insulin-like growth factor I (IGF-I) level, body weight, jejunal and ileal villous height and mucosal thickness, and peak plasma (14)C and (3)H levels. Glutamine supplementation did not produce a significant difference; however, combined with GH treatment, glutamine supplementation further increased body weight, plasma IGF-I level, jejunal and ileal villous height and mucosal thickness, and peak plasma (14)C and (3)H levels significantly. Conclusions. After massive small bowel resection, enteral glutamine supplementation alone has no remarkable beneficial effect on bowel adaptation. However, glutamine supplementation enhanced the gut-trophic effect of GH.

Spatiotemporal dynamics of brain-derived neurotrophic factor mRNA induction in the vestibulo-olivary network during vestibular compensation

Vestibular compensation, which is the behavioral recovery from vestibular dysfunction produced by unilateral labyrinthectomy (UL), is attributed to functional and structural reorganization of neural networks in the central vestibular system. To assess the possible contribution of brain-derived neurotrophic factor (BDNF) to this recovery process, we investigated changes in mRNA expression levels in the central vestibular system after UL. We evaluated BDNF mRNA expression levels by quantitative reverse transcription-PCR and in situ hybridization. We found that BDNF mRNA is differentially induced in the medial vestibular nucleus ipsilateral to UL and in the prepositus hypoglossi and inferior olive on the contralateral side. The BDNF mRNA induction lasted for at least 24 hr and returned to the basal expression level within 72 hr after UL. In contrast to BDNF mRNA induction, the expression of an immediate-early gene, c-fos, quickly reached the maximum level at 3 hr and decreased to the basal level within 24 hr after UL. Neither BDNF or c-fos induction was observed in sham-operated animals. The persistent induction of BDNF after UL temporally corresponded to early behavioral manifestations of vestibular compensation. We further found that trkB mRNA was expressed in the central vestibular network at high levels, although its expression levels did not change over time after UL. Because BDNF is implicated in regulating synaptic structure and function, these results provide support for the hypothesis that BDNF is involved in neuronal reorganization that allows vestibular compensation.

[High efficient intergeneric chromosomal translocations between wheat (Triticum aestivum L.) and Dasypyrum villosum arising from tissue culture and irradiation]

Intergeneric chromosomal translocations were discernable both in callus cells and in regenerants arising from crosses between Triticum aestivum and T. durum-Dasypyrum villosum amphiploid c.v. TH1 and TH1W by means of fluorescence in situ hybridization. There were not only reciprocal translocations, but small fragment translocations. The results proved again the feasibility of creating intergeneric translocations via tissue culture. Irradiation facilitated numerical and structural chromosome changes in callus cells. The frequency of translocations was as high as 7.4 percent in irradiated callus cells. Callus age had an important impact on numerical and structural chromosome abnormalities. During a given time of culture, the frequency of unchanged cells was declined, while those cells with chromosome losses were inclined. The duration of culture had not significant effects on cells with chromosome gains. As structural chromosome changes is concerned, the duration of culture predominantly increased the frequency of cells with telocentric chromosomes. The chromosomal changes occurred at the initiation period of tissue culture. A number of cells which were doubled their chromosome numbers (2n = 84) were observed at a certain frequency in the period of tissue culture. These cells, however, disappeared in the successive culture.

Effect of bowel rehabilitative therapy on structural adaptation of remnant small intestine: animal experiment

AIM: To investigate the individual and the combined effects of glutamine, dietary fiber, and growth hormone on the structural adaptation of the remnant small bowel.

METHODS: Forty-two adult male Sprague-Dawley rats underwent 85% mid-small bowel resection and received total parenteral nutrition (TPN) support during the first three postoperational days. From the 4th postoperational day, animals were randomly assigned to receive 7 different treatments for 8 d: TPNcon group, receiving TPN and enteral 20 g·L^-1 glycine perfusion; TPN + Gln group, receiving TPN and enteral 20 g·L^-1 glutamine perfusion; ENcon group, receiving enteral nutrition (EN) fortified with 20 g·L^-1 glycine; EN + Gln group, enteral nutrition fortified with 20 g·L^-1 glutamine; EN + Fib group, enteral nutrition and 2 g·L^-1 oral soybean fiber; EN + GH group, enteral nutrition and subcutaneous growth hormone (GH) (0.3IU) injection twice daily; and ENint group, glutamine-enriched EN, oral soybean fiber, and subcutaneous GH injection.

RESULTS: Enteral glutamine perfusion during TPN increased the small intestinal villus height (jejunal villus height 250 µm ± 29 µm in TPNcon vs 330 µm ± 54 µm in TPN + Gln, ileal villus height 260 µm ± 28 µm in TPNcon vs 330 µm ± 22 µm in TPN + Gln, P < 0.05) and mucosa thickness (jejunal mucosa thickness 360 µm ± 32 µm in TPNcon vs 460 µm ± 65 µm in TPN +Gln, ileal mucosa thickness 400 µm ± 25 µm in TPNcon vs 490 µm ± 11 µm in TPN + Gln, P < 0.05) in comparison with the TPNcon group. Either fiber supplementation or GH administration improved body mass gain (end body weight 270 g ± 3.6 g in EN + Fib, 265.7 g ± 3.3 g in EN + GH, vs 257 g ± 3.3 g in ENcon, P < 0.05), elevated plasma insulin-like growth factor (IGF-I) level (880 µg·L^-1± 52 µg·L^-1 in EN + Fib, 1200 µg·L^-1± 96 µg·L^-1 in EN ± GH, vs 620 µg·L^-1± 43 µg·L^-1 in ENcon, P < 0.05), and increased the villus height (jejunum 560 µm ± 44 µm in EN ± Fib, 530 µm ± 30 µm in EN ± GH, vs 450 µm ± 44 µm in ENcon, ileum 400 µm ± 30 µm in EN + Fib, 380 µm ± 49 µm in EN ± GH, vs 320 µm ± 16 µm in ENcon, P < 0.05) and the mucosa thickness (jejunum 740 µm ± 66 µm in EN ± Fib, 705 µm ± 27 µm in ENGH, vs 608 µm ± 58 µm in ENcon, ileum 570 µm ± 27 µm in EN ± Fib, 560 µm ± 56 µm in EN ± GH, vs 480 µm ± 40 µm in ENcon, P < 0.05) in remnant jejunum and ileum. Glutamine-enriched EN produced little effect in body mass, plasma IGF-I level, and remnant small bowel mucosal structure. The ENint group had greater body mass (280 g ± 2.2 g), plasma IGF-I level (1450 µg·L^-1± 137 µg·L^-1), and villus height (jejunum 620 µm ± 56 µm, ileum 450 µm ± 31 µm) and mucosal thickness (jejunum 800 µm ± 52 µm, ileum 633 µm ± 33 µm) than those in ENcon, EN + Gln (jejunum villus height and mucosa thickness 450 µm ± 47 µm and 610 µm ± 63 µm, ileum villus height and mucosa thickness 330 µm ± 39 µm and 500 µm ± 52 µm), EN + GH groups (P < 0.05), and than those in EN + Fib group although no statistical significance was attained.

CONCLUSION: Both dietary fiber and GH when used separately can enhance the postresectional small bowel structural adaptation. Simultaneous use of these two gut-trophic factors can produce synergistic effects on small bowel structural adaptation. Enteral glutamine perfusion is beneficial in preserving small bowel mucosal structure during TPN, but has little beneficial effect during EN.

S-Phase arrest by nucleoside analogues and abrogation of survival without cell cycle progression by 7-hydroxystaurosporine

The mechanisms of resistance to nucleoside analogues established in preclinical models are rarely found in primary tumors resistant to therapy with these agents. We tested the hypothesis that cells sense sublethal incorporation of analogues into DNA during replication and react by arresting further DNA synthesis and cell cycle progression. After removal of drug, cells may be able to repair damaged DNA and continue proliferation, thus escaping nucleoside analogue toxicity. As a corollary, we evaluated whether dysregulation of this mechanism causes cell death. Using gemcitabine as a model of S-phase-specific nucleoside analogues in human acute myelogenous leukemia ML-1 cells, we found that DNA synthesis decreased, cells arrested in S-phase transit, and 60-70% of the population accumulated in S-phase in response to cytostatic conditions. Proliferation continued after washing the cells into drug-free medium. S-phase-arrested cells were then treated with otherwise nontoxic concentrations of UCN-01, which caused rapid onset of apoptosis without cell cycle progression specifically in cells with an S-phase DNA content. Thus, S-phase arrest by nucleoside analogues sensitizes cells to UCN-01, which appears to activate signaling for death mechanisms and/or inhibit survival pathways. These results differ from those in cells arrested at the G2 checkpoint, in which UCN-01 abrogates cell cycle arrest, permitting cells to progress in the cell cycle before apoptosis.

Localization of the mouse kidney disease (kd) gene to a YAC/BAC contig on Chromosome 10

Mice that are homozygous for the kidney disease (kd) gene on Chromosome (Chr) 10 spontaneously develop a progressive and fatal interstitial nephritis. The disease phenotype is similar to that of the human disease, juvenile nephronophthisis. Using a backcross and intercross breeding strategy and analysis of over 900 resultant progeny, this genetic locus has now been mapped to a minimal co-segregating region of approximately two megabases between D10Mit 193 and D10Mit 38. The location assigned to kd by this study is over 3 cM from the current Mouse Genome Database location. The entire interval has been cloned in yeast artificial chromosome (YAC) and bacterial artificial chromosome (BAC) clones. Recombinant analysis has permitted assignment of 13 Mit microsatellite markers to positions near or within the region. Two new markers have been identified by using single-strand conformation polymorphism (SSCP) analysis of sequenced BAC ends. Several BAC end sequences align with human BAC clones from Chr 6q2 that contain NR2E1. Snx3, and Ros1. Three murine genes, CD24a, fyn, and ColX reported to map in or near the kd region as defined by this study have been evaluated. Though not definitely excluded, they appear to be unlikely candidates.

Cocaine increases beta-myosin heavy-chain protein expression in cardiac myocytes

BACKGROUND

As many as 47% of chronic cocaine users develop cardiac ventricular hypertrophy. The presence and degree of cocaine-induced ventricular hypertrophy is not correlated with the use of other substances of abuse such as alcohol or cigarettes. Moreover, this hypertrophy occurs in individuals without sustained increases in arterial blood pressure or heart rate, or increases in the plasma concentration of renin, aldosterone, norepinephrine, or cortisol. Therefore, we investigated whether cocaine, in concentrations commonly found in cocaine users, has any direct effects on the protein content in cardiac ventricular myocytes. We compared the effects of cocaine with norepinephrine, which increases the total protein content, especially beta-myosin heavy-chain contractile protein (beta-MHC), in cardiac ventricular myocytes.

METHODS

Experiments were performed on 30-day-old rat ventricular myocytes suspended in culture media and cultured in flasks. In 12 suspension-culture experiments, cocaine or norepinephrine, in doses of 0 (control) or 10(-6) mol/L was added to each culture and the cells were harvested on day 5. In 16 flask-culture experiments, cocaine or norepinephrine was added to each culture on day 7 in doses of 0 (control-vehicle), 10(-7), or 10(-6) mol/L and the cells were harvested on day 10. The total protein content and the myosin protein expression of the myocytes in each culture were determined. Juvenile and adult rat cardiac myosin protein is predominately alpha-myosin heavy-chain protein (alpha-MHC), whereas beta-MHC occurs primarily in fetal rat hearts.

RESULTS

In the suspension-culture experiments, cocaine, 10(-6) mol/L, increased the cardiomyocyte total protein concentration by 29% +/- 2% (P <.001) and the beta-MHC expression by 81% +/- 10% (P <.01) in comparison with the control myocytes. Cocaine slightly decreased cardiomyocyte alpha-MHC. Norepinephrine increased the total protein concentration by 21% +/- 3% (P <.001) and the beta-MHC expression by 59% +/- 10% (P <.01), but did not increase alpha-MHC expression. In the flask-culture experiments, cocaine, 10(-6) mol/L, maximally increased the total protein concentration by 28% (P <.001), the protein/cell ratio by 57% +/- 10% (P <.01), and the beta-MHC expression by 85% +/- 8% (P <.01). Cocaine slightly decreased alpha-MHC. Norepinephrine, 10(-6) mol/L, maximally increased the total protein concentration by 35%, the protein/cell ratio by 63% +/- 9% (P <.01), and the expression of beta-MHC by 78% +/- 11% (P <. 01). Norepinephrine did not increase alpha-MHC expression. In 18 separate flask-culture experiments, cocaine, 10(-6) mol/L, was added to the cardiomyocyte cultures after the addition of phentolamine (n = 9), in concentrations of 10(-7) to 10(-5) mol/L, or metoprolol (n = 9), in concentrations of 10(-7) to 10(-5) mol/L. Neither phentolamine nor metoprolol inhibited the cocaine-induced increase in cardiomyocyte total protein content or the expression of beta-MHC.

CONCLUSION

Cocaine, similar to norepinephrine, significantly increases the total protein content and the expression of beta-MHC in cardiac ventricular myocytes. In this manner, cocaine may cause cardiac ventricular hypertrophy. This process is not inhibited by alpha- or beta-adrenergic receptor blockade.

Identification of a locus for disseminated superficial actinic porokeratosis at chromosome 12q23.2-24.1

Disseminated superficial actinic porokeratosis is an autosomal dominant cutaneous disorder characterized by many uniformly small, minimal, annular, anhidrotic, and keratotic lesions. The genetic basis for this disease is unknown. Using a genomewide search in a large Chinese family, we identified a locus at chromosome 12q23.2-24. 1 responsible for disseminated superficial actinic porokeratosis. The fine mapping study indicates that the disseminated superficial actinic porokeratosis gene is located within a 9.6 cM region between markers D12S1727 and D12S1605, with a maximum two-point LOD score of 20.53 (theta = 0.00) at D12S78. This is the first locus identified for a genetic disease where the major phenotype is porokeratosis. The study provides a map location for isolation of a gene causing disseminated superficial actinic porokeratosis.

Quantitative analysis of thymosin alpha1 in human serum by LC-MS/MS

A high performance liquid chromatography with tandem mass spectrometry (LC-MS/MS) method was developed to measure the thymosin alpha 1 (Talpha1) concentration in human serum. Tá1 in human serum was determined by solid phase extraction and reverse phase LC-MS/MS. The high-performance liquid chromatography (HPLC) system interfaced with the MS/MS system with a Turbo Ion spray interface. Positive ion detection and multiple reaction monitoring (MRM) mode were used for this human serum quantitation. Eight different concentration standards were used to establish the detection range. Six quality control (QC) and 2 matrix blanks were checked by calibration curves performed on the same day. The lower quantitation limit was 0.5 ng/mL Talpha1 in human serum. Calibration curves were established between 0.5 to 100 ng/mL by weighted linear regression. The correlation coefficients for different days were 0.9955 or greater. Quantitation of Talpha1 by the LC-MS/MS method is fast, accurate, and precise.

Expression of brain-derived neurotrophic factor, neurotrophin-3 and their receptor messenger RNAs in monkey rhinal cortex

The primate rhinal cortex, consisting of areas 36 and 35 of the perirhinal cortex and the entorhinal cortex (area 28), plays a crucial role in perception and memory. We investigated the expression of messenger RNAs for brain-derived neurotrophic factor and neurotrophin-3, as well as those for their respective tyrosine kinase receptors, TrkB and TrkC, in the monkey rhinal cortex. Results from in situ hybridization revealed that each of these messenger RNAs was expressed in neurons with distinct laminar and areal patterns of distribution. Brain-derived neurotrophic factor messenger RNA was principally detected in layers V/ VI of area 36, and layers II/III and V of the entorhinal cortex. Some of the messenger RNA-positive cells in the deep layers of the rhinal cortex were confirmed to exhibit a pyramidal cell-like morphology. Neurotrophin-3 messenger RNA expression was confined to layers II/III of the entorhinal cortex. In contrast, trkB and trkC messenger RNAs were expressed rather homogeneously and abundantly throughout the rhinal cortex. The laminar and cellular distributions of brain-derived neurotrophic factor and neurotrophin-3 messenger RNAs indicate the predominant expression of these neurotrophins in projection neurons. These results suggest that brain-derived neurotrophic factor and neurotrophin-3 regulate neuronal connectivities of forward and backward projections from the rhinal cortex and contribute to functional reorganization underlying the formation and maintenance of long-term memory in primates.

Clinicopathological features of aggressive large granular lymphocyte leukaemia resemble Fas ligand transgenic mice

Fas ligand triggers cell death after interaction with its receptor Fas. Altered expression of Fas has been associated with lymphoproliferation and autoimmune disorders in both mice and man. Apoptosis of lung and liver tissue is seen in Fas ligand transgenic mice. It is not known whether constitutive expression of Fas ligand can cause a similar human disease. Four patients with aggressive large granular lymphocyte (LGL) leukaemia involving lung and liver were studied. All four patients were severely ill with pulmonary involvement. Two patients presented with hypoxia and were oxygen dependent; the other two patients had severe pulmonary hypertension. Lung biopsies showed interstitial infiltration by leukaemic LGL. The infiltrating lymphocytes expressed both Fas and Fas ligand, whereas normal pneumocytes expressed only Fas. Similar findings were observed in liver biopsies from these patients. Features mimicking the pathological changes of graft-versus-host disease were observed, including pneumocyte apoptosis. All four patients had high levels of circulating Fas ligand. Successful treatment with oral methotrexate or 2-chlorodeoxyadenosine was associated with disappearance or marked reduction of circulating Fas ligand. These results suggest that dysregulated expression of Fas ligand can lead to human disease with pathological features resembling graft-versus-host disease.

Branched biodegradable polyesters for parenteral drug delivery systems

Continuous, 'infusion-like' drug release profiles from biodegradable parenteral delivery systems are difficult to achieve for proteins and other hydrophilic macromolecular drugs with commonly used linear polyesters from lactic acid (PLA) and its random copolymers with glycolic acid (PLG). Drug release rates can be modified either by increasing the hydrophilicity of polyesters or by manipulating the polymer architecture to adjust polymer degradation rates and thus drug release. Therefore, we investigated different branching concepts for biodegradable polyesters of PLA and PLG. For one four- and eight-arm poly(ethylene oxide)s (PEO) were grafted with shorter polyester chains leading to star-branched structures. Secondly we obtained comb-like polyesters using both charged and uncharged dextrans or poly(vinyl alcohol)s (PVA) as hydrophilic backbones. The star-shaped and brush-like grafted polymers were intensively characterized by methods, such as NMR, IR, SEC-SLS, DSC and viscosity measurements. Tailor-made properties make these novel biodegradable polyesters promising candidates for parenteral protein delivery systems. While the star-branched polyesters have shown some interesting properties with respect to their degradation behavior, retaining the PEO blocks longer than ABA triblock copolymers, their release properties need further optimization. Brush-like branched polyesters on the other hand seem to possess both degradation and release properties meriting further investigations for parenteral protein delivery systems.

Effect of PKC-zeta mediating Ang II-stimulated activation of CCDPK on rat cardiac fibroblast proliferation

AIM

To investigate whether the effect of angiotensin (Ang) II or epidermal growth factor (EGF) on cardiac fibroblast proliferation involved in activation of extracellular signal-regulated kinase (ERK) 1/2 or Ca(2+)-calmodulin dependent protein kinase(CCDPK) mediated by protein kinase C (PKC)-zeta.

METHODS

Relative activity of CCDPK was measured by Western blotting. DNA synthesis was assayed by [3H]thymidine incorporation.

RESULTS

PDBU caused no decrease in Ang II- and 10% FCS-stimulated CCDPK activity and DNA synthesis. In contrary, 65% or 75% EGF- or tetradecanoylphorbol acetate (TDPA, formally called PMA)--stimulated CCDPK activity and 38% or 42% [3H]thymidine incorporation treated by PDBU were inhibited, respectively. Meanwhile 70% and 72% CCDPK activities induced by Ang II and EGF were inhibited by PD 98059, respectively.

CONCLUSION

PKC-zeta mediated Ang II-induced activation of CCDPK and cardiac fibroblast proliferation.

Expression of GIRK (Kir3.1/Kir3.4) channels in mouse fibroblast cells with and without beta1 integrins

G protein-activated K+ channel (GIRK) subunits possess a conserved extracellular integrin-binding motif (RGD) and bind directly to beta1 integrins. We expressed GIRK1/GIRK4 channels labeled with green fluorescent protein in fibroblast cell lines expressing or lacking beta1 integrins. Neither plasma membrane localization nor agonist-evoked GIRK currents were affected by the absence of beta1 integrins or by incubation with externally applied RGD-containing peptide. Mutation of the aspartate (D) of RGD impaired currents, GIRK glycosylation, and membrane localization, but the interaction with beta1 integrins remained intact. Thus, beta1 integrins are not essential for functional GIRK expression; and the GIRK-integrin interactions involve structural elements other than the RGD motif.

Double-stranded RNA injection produces null phenotypes in zebrafish

Zebrafish is a simple vertebrate that has many attributes that make it ideal for the study of developmental genetics. One feature that has been lacking in this model system is the ability to disable specifically targeted genes. Recently, double-stranded RNA has been used to silence gene expression in the nematode Caenorhabditis elegans. We have found that expression of the green fluorescent protein (GFP) from a microinjected plasmid vector can be suppressed in zebrafish embryos by the coinjection of a double-stranded RNA that is specifically targeted to GFP. To determine that double-stranded RNA can attenuate endogenous gene expression, single-cell zebrafish embryos were injected with double-stranded RNA specifically targeted to Zf-T and Pax6.1. We found that microinjection of double-stranded Zf-T RNA resulted in a high incidence of a phenotype similar to that of ntl. Furthermore, Zf-T gene expression could not be detected by in situ hybridization and the message was decreased by 75% by semiquantitative RT-PCR in 12-h embryos that had been injected with the double-stranded RNA. Expression of the zebrafish genes sonic hedgehog and floating head was altered in the embryos microinjected with the Zf-T double-stranded RNA in a manner that is remarkably similar to the zebrafish no-tail mutant. Microinjection of double-stranded RNA targeted to Pax6.1 was associated with depressed expression of Pax6. 1 and resulted in absent or greatly reduced eye and forebrain development, similar to the phenotype seen in mouse mutants. Simultaneous injection of Pax6.1 and Zf-T resulted in embryos lacking notochords, eyes, and brain structures.

Quantification of neurotrophin-3 mRNA in the rat hippocampal subregions using the RT-PCR-based coamplification method

Quantitative reverse transcription-polymerase chain reaction (RT-PCR) is a suitable method for determining the expression levels of rare mRNAs in small amounts of tissue. To compare the mRNA expression levels across specific brain regions, we adopted an RT-PCR method in which a target gene was coamplified with an endogenous internal standard gene in single reaction tubes. Use of the endogenous internal standard can control fluctuations in target quantification resulting from various factors, including tube-to-tube variation in amplification efficiency and variation in mRNA content among the total RNAs prepared from different tissues. In this study, we quantitatively determined the mRNA expression levels for NT-3, a member of the neurotrophin family of growth factors, in the hippocampal subregions: the entorhinal cortex, dentate gyrus and CA1. NT-3 gene was simultaneously coamplified with an endogenous internal standard gene, hypoxanthine-guanine phosphoribosyltransferase (HPRT), in the same reaction tube. Using this RT-PCR coamplification method, we detected a regional difference in the NT-3 mRNA expression levels across the hippocampal subregions. Our method can serve as a useful quantification method to investigate molecular signaling cascades in a specific cortical region.

Sensitizing human cervical cancer cells In vitro to ionizing radiation with interferon beta or gamma

Human cervical cancer is often associated with human papilloma virus (HPV). HPV products, such as the oncoproteins E6 and E7, are known to disrupt the function of TP53 (formerly known as p53). The protein encoded by the TP53 gene plays a central role in managing cellular damage. Interferons are known to down-regulate E6/E7 and may therefore restore TP53 function and influence radiation sensitivity. We investigated whether IFNB or IFNG, at various concentrations (2- 300 IU/ml) and for a range of durations of exposure (from 48 h before to 8 h after irradiation), were able to modify the radiation response of HeLa, C4-1, Me-180, C33-A and SiHa cells. In parallel to the clonogenic assays, we analyzed the effect on the mRNA that encodes IFNB and E6 by Northern blotting in the same experimental conditions. A significant change in the initial slope of the dose-response curve was observed more consistently with IFNB than with IFNG. No changes in the mRNA or protein level of TP53 and E6 could be detected. Thus other mechanisms of action need to be investigated to explain radiosensitization with recombinant IFNB in cells of human cervical cancer cell lines.

The ribonucleoside diphosphate reductase inhibitor (E)-2'-deoxy-(fluoromethylene)cytidine as a cytotoxic radiosensitizer in vitro

(E)-2'-Deoxy-(fluoromethylene)cytidine (FMdC) is known as an inhibitor of ribonucleoside diphosphate reductase, a key enzyme in the de novo pathway of DNA synthesis. FMdC was tested as a modifier of radiation response in vitro on a human colon carcinoma cell line (WiDr), and the observed radiosensitization was confirmed on two human cervix cancer cell lines (C33-A and SiHa). Using the clonogenic assay, the effect ratio (ER) at a clinically relevant dose level of 2 Gy was 2.10 (50 nM FMdC), 1.70 (30 nM FMdC), and 1.71 (40 nM FMdC) for the three cell lines WiDr, C33-A, and SiHa, respectively. A more detailed analysis of the importance of timing and concentration of FMdC was done on the WiDr cell line alone, yielding an increased ER(2Gy) with increasing concentration and duration of exposure to the drug, ranging from 1.0 (6 h) to 1.8 (72 h) at 30 nM FMdC and from 1.2 (6 h) to 3.5 (24 h) at 300 nM. We investigated the effect of FMdC on the cellular deoxynucleotide triphosphate pool in WiDr cells and demonstrated a marked depletion of dATP and a significant rise of TTP levels. Cell cycle analysis showed early S-phase accumulation induced by FMdC alone, G2-M block induced by irradiation alone, and an increased accumulation of cells in G2-M if both modalities are used. Our data suggest that FMdC is a radiation response modifier in vitro on different cancer cell lines. The observed radiosensitization may in part be explained by alteration of the deoxynucleotide triphosphate pool, which is consistent with the effect of FMdC on ribonucleoside diphosphate reductase.