Quantum theory for cold avalanche ionization in solids

A theory of photon-assisted impact ionization in solids is presented. Our theory makes a quantum description of the new impact ionization-cold avalanche ionization recently reported by P. P. Rajeev, M. Gertsvolf, P. B. Corkum, and D. M. Rayner [Phys. Rev. Lett. 102, 083001 (2009)]. The present theory agrees with the experiments and can be reduced to the traditional impact ionization expression in the absence of a laser.

Hepatic expression of CYP3A4 and CYP3A5 genes in Asians and implications for pharmacokinetic variations during chemotherapy

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Background: Hepatic expression of CYP3A4 and CYP3A5 enzymes are important determinants of interindividual variability in chemotherapy. The objective of this study was to genotypically quantitate expression of CYP3A4 and CYP3A5 genes in healthy hepatic tissues from Asian cancer patients undergoing hepatectomy. Methods: Healthy Asian hepatic tissues (Chinese: N = 27; Malay: N = 1; Indian: N = 3) were obtained from the institution’s central tissue repository bank. Messenger RNA was isolated from each tissue sample and reversed transcribed to cDNA followed by real time PCR experiments. Results from these gene expression experiments were normalized against GAPDH transcripts. DNA was also extracted from the hepatocytes and genotyped for four single nucleotide polymorphisms in the CYP3A4 gene (CYP3A4*1B, *4, *5 and *6) and three in the CYP3A5 gene (CYP3A5*1, *3 and *6). Results: CYP3A4 variant forms were absent in all Asian patients. CYP3A5 was polymorphic and genotyping analysis showed that the *1/*1, *1/*3 and *3/*3 genotypes were present in 6%, 52% and 42% of the Asian liver samples, respectively. Liver tissues harbouring the *1/*1 and *1/*3 genotypes showed insignificant CYP3A5 expression pattern (P=0.160). The CYP3A5 mRNA expression levels were approximately 6-fold lower in *3/*3 samples compared with samples carrying at least one *1 allele (*1/*1 + *1/*3). Non-parametric analysis using Kruskal-Wallis test showed that the hepatic expression of CYP3A5 mRNA between liver tissues that harboured at least one *1 allele (*1/*1 + *1/*3) and those carrying homozygous *3/*3 genotype to be highly significantly different (P < 0.007). Conclusions: These results show that polymorphic CYP3A4 isoforms are probably rare in Asians compared with CYP3A5 polymorphisms. This study also suggest that CYP3A5, rather than CYP3A4 could be important for interindividual variations in pharmacokinetics of CYP3A4/5 substrates during chemotherapy in Asians.

No significant financial relationships to disclose.

ZnO nanoparticles embedded in sapphire fabricated by ion implantation and annealing

ZnO nanoparticles were fabricated in sapphire (α-Al(2)O(3) single crystal) by Zn ion implantation (48 keV) at an ion fluence of 1 × 10(17) cm(-2) and subsequent thermal annealing in a flowing oxygen atmosphere. Transmission electron microscopy (TEM) analysis revealed that metallic Zn nanoparticles of 3-10 nm in dimensions formed in the as-implanted sample and that ZnO nanoparticles of 10-12 nm in dimensions formed after annealing at 600 °C. A broad absorption band, peaked at 280 nm, appeared in the as-implanted crystal, due to surface plasma resonance (SPR) absorption of metallic Zn nanoparticles. After annealing at 600 °C, ZnO nanoparticles resulted in an exciton absorption peak at 360 nm. The photoluminescence (PL) of the as-implanted sample was very weak when using a He-Cd 325 nm line as the excitation source. However, two emission peaks appeared in the PL spectrum of ZnO nanopraticles, i.e., one ultraviolet (UV) peak at 370 nm and the other a green peak at 500 nm. The emission at 500 nm is stronger and has potential applications in green/blue light-emitting devices.

Functional analysis of a novel male fertility CYP86MF gene in Chinese cabbage (Brassica campestris L. ssp. chinensis makino)

In our earlier work, a cytochrome P450 CYP86MF gene was isolated from floral bud of Chinese cabbage (Brassica campestris L. ssp. chinensis Makino, syn. B. rapa L.) by mRNA differential display PCR (DD-PCR) and rapid amplification of cDNA ends (RACE). To unravel the biological function of CYP86MF gene, the antisense fragment from the CYP86MF gene was transferred into Chinese cabbage pak-choi (B. campestris ssp. chinensis var. communis Tsen et Lee). Out of 22 plants transformed with the antisense gene constructed from the CYP86MF, 20 reached to flowering stage. Morphological investigations showed that the transgenic plants developed the normal floral organ. However, they remained self-infertile, even when artificial self-pollination was performed in the bud stage. Pollen germination test indicated that the pollen from the transgenic line TB-2 could not germinate normally. Further physiological, biochemical and cytological analyses showed that only significant difference was detectable in contents of the endogenous hormones, and a layer of unknown material adhered to the surface of microspore. The present studies thus provided valuable clues for understanding the biological function of the CYP86C subfamily genes. Furthermore, our studies also demonstrate a novel method for obtaining artificial male sterility line of Chinese cabbage.

[A role of nitric oxide and endothelin in bronchial hyperreactivity in patients with mild and middle asthma]

OBJECTIVES

To probe into a role of nitric oxide(NO) and endothelin(ET) in bronchial hyperreactivity(BHR) in patients with mild and middle asthma.

METHODS

MchPC20 was used as an index to evaluate BHR in the asthmatic patients. Endothelin and NO level in bronchial alveolar lavage fluid(BALF) obtained from 15 patients with attacking asthma(Group I), 8 patients with stable asthma (Group II) and 7 healthy control subjects (Group III) were examined by radioimmunoassay and copper coated cadmium reduction method, respectively.

RESULTS

1. MchPC20 and FEV1% in Group III were slightly higher than those in Group I (P < 0.05), and lower than those in Group III (P < 0.05), respectively; 2. NO and ET levels in BALF from Group I were higher than those from Group II and Group III (P < 0.05), respectively; 3. ET/NO ratio in Group I was higher than that in Group III (P < 0.05) and lower than that in Group II (P > 0.05); 4. NO and ET level in BALF from Group I were positively and negatively correlated with MchPC20, respectively(r = 0.83, P < 0.01; r = 0.75, P < 0.01); the correlation of NO and ET level in BALF from Group I was negative (r = 0.70, P < 0.01); 5. NO and ET levels in BALF and ET/NO ratio from Group II were slightly higher than those from Group III (P < 0.05), respectively.

CONCLUSION

NO may improve and ET exacerbate BHR in patients with mild and middle asthma. Bronchial hyperreactivity of the patients with stable asthma displays lightly abnormal, which may be due to mild abnormality of NO, ET levels and ET/NO ratio in BALF.

[Establishment of Hymenolepis diminuta-animal model and morphology of cysticercoid]

AIM

To observe the morphological changes in the process of the development of Hymenolepis diminuta.

METHODS

The life cycle of Hymenolepis diminuta was established between Rattus domesticus albus and Triboliun castaneum. The morphology of cysticercoid were observed microscopically, and the ultrastructure of the body surface of cysticercoid were observed by scanning electron microscopy.

RESULTS

Three phases including the mature stage, the blister stage and the protective outer membrane-forming stage during the growing course of cysticercoid were observed microscopically. Under scanning electron microscope, lots of sieve-like micropores on the surface of mature cysticercoid were seen in the second week after infection. The blister phase was found in the third week and the outer membrane measuring about 45 microns in thickness were found surrounding the cysticercoid and vesicular surface, forming a smooth cyst wall in the fourth week.

CONCLUSION

The life cycle of Hymenolepis diminuta has been established in the animal-model. The finding of the three phases during the growing course of cysticercoid is reported for the first time.

Allurin, a 21-kDa sperm chemoattractant from Xenopus egg jelly, is related to mammalian sperm-binding proteins

Previously, we demonstrated that a protein from Xenopus egg jelly exhibits sperm chemoattractant activity when assayed by either video microscopy or by sperm passage across a porous filter. Here we describe the isolation and purification of allurin, the protein responsible for this activity. Freshly oviposited jellied eggs were soaked in buffer, and the conditioned medium was loaded onto an anion exchange column and eluted with an NaCl gradient. The active fraction was purified further by RP-HPLC, the chemoattractant protein appearing as a single sharp peak. The amino acid sequence of the protein, determined by direct sequencing and cloning of cDNAs coding for the protein, consisted of 184 amino acids having a molecular mass of 21,073 Da. The protein shares homology with the mammalian cysteine-rich secretory protein (CRISP) family that includes testes-specific spermatocyte protein 1, a cell adhesion protein which links spermatocytes to Seritoli cells, and acidic epididymal glycoproteins that bind to sperm and have been implicated in sperm-egg fusion. Phylogenetic analysis suggests that allurin evolved from the ancestral protein that gave rise to the mammalian CRISP family. Addition of allurin to this family portends that the CRISP family represents a group of "sperm escort" proteins, which bind to sperm at various steps in their life history, facilitating passage from one functional stage to the next. Allurin stands out in this regard, representing both the first vertebrate sperm chemoattractant to be purified and sequenced and the first member of the CRISP family to be found in the female reproductive tract.

Phase III, multicenter, double-blind, randomized study of letrozole, an aromatase inhibitor, for advanced breast cancer versus megestrol acetate

PURPOSE

To compare two doses of letrozole (0.5 mg and 2.5 mg every day) and megestrol acetate (40 mg qid) as endocrine therapy in postmenopausal women with advanced breast cancer previously treated with antiestrogens.

PATIENTS AND METHODS

This double-blind, randomized, multicenter, multinational study enrolled 602 patients, all of whom were included in the primary analysis in the protocol. Patients had advanced or metastatic breast cancer with evidence of disease progression while receiving continuous adjuvant antiestrogen therapy, had experienced relapse within 12 months of stopping adjuvant antiestrogen therapy given for at least 6 months, or had experienced disease progression while receiving antiestrogen therapy for advanced disease. Tumors were required to be estrogen receptor- and/or progesterone receptor-positive or of unknown status. Confirmed objective response rate was the primary efficacy variable. Karnofsky Performance Status and European Organization for Research and Treatment of Cancer quality-of-life assessments were collected for 1 year.

RESULTS

There were no statistically significant differences among the three treatment groups for overall objective tumor response. Patients treated with letrozole 0.5 mg had improvements in disease progression (P =.044) and a decreased risk of treatment failure (P =.018), compared with patients treated with megestrol acetate. Letrozole 0.5 mg showed a trend (P =.053) for survival benefit when compared with megestrol acetate. Megestrol acetate was more likely to produce weight gain, dyspnea, and vaginal bleeding, and the letrozole groups were more likely to experience headache, hair thinning, and diarrhea.

CONCLUSION

Given a favorable tolerability profile, once-daily dosing, and evidence of clinically relevant benefit, letrozole is equivalent to megestrol acetate and should be considered for use as an alternative treatment of advanced breast cancer in postmenopausal women after treatment failure with antiestrogens.

The Aspergillus cytoplasmic dynein heavy chain and NUDF localize to microtubule ends and affect microtubule dynamics

Cytoplasmic dynein is a multisubunit, minus end-directed microtubule motor that uses dynactin as an accessory complex to perform various in vivo functions including vesicle transport, spindle assembly, and nuclear distribution [1]. We previously showed that in the filamentous fungus Aspergillus nidulans, a GFP-tagged cytoplasmic dynein heavy chain (NUDA) forms comet-like structures that exhibited microtubule-dependent movement toward and back from the hyphal tip [2]. Here we demonstrate that another protein in the NUDA pathway, NUDF, which is homologous to the human LIS1 protein involved in brain development [3, 4], also exhibits such dynamic behavior. Both NUDA and NUDF are located at the ends of microtubules, and this observation suggests that the observed dynamic behavior is due to their association with the dynamic microtubule ends. To address whether NUDA and NUDF play a role in regulating microtubule dynamics in vivo, we constructed a GFP-labeled alpha-tubulin strain and used it to compare microtubule dynamics in vivo in wild-type A. nidulans versus temperature-sensitive loss-of-function mutants of nudA and nudF. The mutants showed a lower frequency of microtubule catastrophe, a lower rate of shrinkage during catastrophe, and a lower frequency of rescue. The microtubules in the mutant cells also paused longer at the hyphal tip than wild-type microtubules. These results indicate that cytoplasmic dynein and the LIS1 homolog NUDF affect microtubule dynamics in vivo.

Microtubule integrity regulates Pak leading to Ras-independent activation of Raf-1. insights into mechanisms of Raf-1 activation

Growth factors activate Raf-1 by engaging a complex program, which requires Ras binding, membrane recruitment, and phosphorylation of Raf-1. The present study employs the microtubule-depolymerizing drug nocodazole as an alternative approach to explore the mechanisms of Raf activation. Incubation of cells with nocodazole leads to activation of Pak1/2, kinases downstream of small GTPases Rac/Cdc42, which have been previously indicated to phosphorylate Raf-1 Ser(338). Nocodazole-induced stimulation of Raf-1 is augmented by co-expression of small GTPases Rac/Cdc42 and Pak1/2. Dominant negative mutants of these proteins block activation of Raf-1 by nocodazole, but not by epidermal growth factor (EGF). Thus, our studies define Rac/Cdc42/Pak as a module upstream of Raf-1 during its activation by microtubule disruption. Although it is Ras-independent, nocodazole-induced activation of Raf-1 appears to involve the amino-terminal regulatory region in which the integrity of the Ras binding domain is required. Surprisingly, the Raf zinc finger mutation (C165S/C168S) causes a robust activation of Raf-1 by nocodazole, whereas it diminishes Ras-dependent activation of Raf-1. We also show that mutation of residues Ser(338) to Ala or Tyr(340)-Tyr(341) to Phe-Phe immediately amino-terminal to the catalytic domain abrogates activation of both the wild type and zinc finger mutant Raf by both EGF/4beta-12-O-tetradecanoylphorbol-13-acetate and nocodazole. Finally, an in vitro kinase assay demonstrates that the zinc finger mutant serves as a better substrate of Pak1 than the wild type Raf-1. Collectively, our results indicate that 1) the zinc finger exerts an inhibitory effect on Raf-1 activation, probably by preventing phosphorylation of (338)SSYY(341); 2) such inhibition is first overcome by an unknown factor binding in place of Ras-GTP to the amino-terminal regulatory region in response to nocodazole; and 3) EGF and nocodazole utilize different kinases to phosphorylate Ser(338), an event crucial for Raf activation.

Comparison of different methods of total RNA extraction for viral detection in sputum

Examination of sputum specimens can be used for monitoring airway inflammation by means of immunological and molecular techniques. RNA extraction is essential for measurement of cytokine gene expression and for detection of many viral pathogens in sputum. In this study, three RNA extraction methods used commonly (acid guanidinium thiocyanate-phenol-chloroform extraction, Trizol and RNeasy Mini kit) were compared on the sputum of 14 patients who had chronic obstructive pulmonary disease. The effect of dithiothreitol pre-treatment on sputum RNA extraction was also investigated. The yield and purity of total RNA were determined by spectrophotometry. Reverse transcription-polymerase chain reaction (RT-PCR) results of the house keeping gene (glyceraldehyde-3-phosphate dehydrogenase) and RNA sequences specific to common respiratory viruses were compared. The results showed that (1) total RNA extracted with Trizol had highest yield and purity among the three RNA extraction methods; (2) there was no significant difference among the three RNA extraction methods on the house keeping gene and viral detection by RT-PCR; (3) dithiothreitol pre-treatment did not improve either the purity of total RNA, or RT-PCR signal. Moreover, dithiothreitol treatment reduced significantly the yield of total RNA. The results of the study indicate that the Trizol method appears to be superior for total RNA extraction from sputum, and dithiothreitol pre-treatment does not increase the efficiency of RNA extraction and RNA detection in sputum specimens.

[Detection of viral aetiology in cerebral spinal fluid samples from 580 clinical cases]

OBJECTIVE

To investigate the viral aetiology in cerebral spinal fluid (Csf) from 580 cases of CNS infection or FUO in Yuedong district from 1990 to 1997.

METHODS

Virus isolation was done with Hep-2 and BHK-21 cells.

RESULTS

21 virus types of 5 kinds of viruses were isolated from 113 samples (19.5%). Clinically diagnosed diseases included viral encephalitis 17.8% (43/242), intracranial infection 20.2% (47/233), paralytic diseases 24.3% (9/37), FUO 37.5% (9/24), convulsion 16.0% (4/25), Guillain-Barre syndrome 5.3% (1/19). Virus infection included 11 cases of Poliovirus (constitutional ratio 0.0973, including 1 Polio-I, 8 Polio-II, 2 Polio-III); 54 cases of Coxsackie virus (0.477 9, including 11 CoxA24, 10 CoxBl, 2 Cox134, 3 CoxB5); 15 cases of ECHO virus (0.1327, including 4 ECHO-24, 3 ECRO-7, 2 ECHO-12 and each one of ECHO-3, 11,14,15,27,32); 25 cases of Enterovirus (0.2213, including 14 EV-70, 11 EV-71); 8 cases of Adenovirus (0.070 8, including 3 Adv-2, 3 Adv-3 and 2 Adv7). Results of different age groups indicated there was significant difference (P < 0.05) in virus detection rate in two age groups. Virus positive rates in different years were 1990-1991 14.2% (15/106), 1992-1993 14.1%(23/163), 1994-1995 26.1% (36/138), 1996-1997 22.5% (39/173), that showed a significant difference (P <0.05).

CONCLUSIONS

Virus infection rate of CNS diseases and FUO showed an a ascending trend, and the different virus types and kinds were isolated in different periods.

[Clinical study on interferon treatment of chronic idiopathic thrombocytopenic purpura]

The efficacy and mechanism of interferon alpha-2a (IFN alpha-2a) were assessed in the treatment of chronic idiopathic thrombocytopenic purpura (cITP). 20 patients with cITP (treatment group) were treated with IFN alpha-2a 3MIU i.m. once a week for 8 weeks; 28 patients with cITP (control group) were treated with prednisone 1 mg/(kg.d) for 4 weeks. Blood platelet counts (BPC), megakaryocyte number, immunnological parameters, percent and absolute counts of reticulated platelets (RPs) and megakaryocyte colony formation units were observed before and after therapy. The results showed that the efficacy of IFN alpha-2a was better than that of corticosteroid, P < 0.05. The RPs% decreased and the platelet-producing megakaryocyte percentage increased from 11.43% to 33.19% significantly after IFN alpha-2a therapy, but there were no significant changes in immunnological parameters. These indicate that IFN alpha-2a is effective in treating cITP, the mechanism may be based on promoting the megakaryocyte development and activating the production of platelets.

Dynamics of cytoplasmic dynein in living cells and the effect of a mutation in the dynactin complex actin-related protein Arp1

Cytoplasmic dynein is a minus-end-directed microtubule motor that participates in multiple cellular activities such as organelle transport and mitotic spindle assembly [1]. To study the dynamic behavior of cytoplasmic dynein in the filamentous fungus Aspergillus nidulans, we replaced the gene for the cytoplasmic dynein heavy chain, nudA, with a gene encoding a green fluorescent protein (GFP)-tagged chimera, GFP-nudA. The GFP-NUDA fusion protein is fully functional in vivo: strains expressing only the GFP-tagged nudA grow as well as wild-type strains. Fluorescence microscopy showed GFP-NUDA to be in comet-like structures that moved in the hyphae toward the growing tip. Retrograde movement of some GFP-NUDA comets after they arrived at the tip was also observed. These dynamics of GFP-NUDA were not observed in cells treated with a microtubule-destabilizing drug, benomyl, suggesting they are microtubule-dependent. The rate of GFP-NUDA tip-ward movement is similar to the rate of cytoplasmic microtubule polymerization toward the hyphal tip, suggesting that GFP-NUDA is associated and moving with the polymerizing ends of microtubules. A mutation in actin-related protein Arp1 of the dynactin complex abolishes the presence of these dynamic GFP-NUDA structures near the hyphal tip, suggesting a targeting role of the dynactin complex.

[Cytomegalovirus infection and the changes of T-lymphocyte subsets in RAU patients]

OBJECTIVE

To study the quantitative changes of the T-lymphocyte subsets in RAU patients with different stages and to know the influences of cytomegalovirus(CMV) on cellular immunity in RAU patients.

METHODS

CD4(helper/inducer) and CD8(suppressor/cytotoxic) cells in the peripheral blood were tested with monoclonally immunocytochemical technique (APAAP method) in 26 ulcerative stage patients and 10 inactive patients.

RESULTS

The percentages of CD4 and CD8 cell were 36.19% and 29.38% respectively in ulcerative stage. The ratio of CD4/CD8 was 1.28 and it was inverted (< 1.0) in 26.92% of the patients. The percentages of CD4, CD8 cells was 39.90% and 34.21% in inactive stage respectively. The ratio of CD4/CD8 was 1.17. The number of CD4 and CD8 cells in ulcerative stage and CD4 cells in inactive stage was significantly lower than the normal values, P < 0.05. The number of CD8 cells in inactive stage was not significantly different compared with the normal value. However the numbers of CD3(total T cells), CD4 and CD8 cells increased to some extent in inactive stage. CD4 cells was significantly lower in 11 human cytomegalovirus (HCMV) DNA positive patients than that in 9 HCMV DNA negative patients (P < 0.05).

CONCLUSIONS

A permanent disorder of cellular immunity was an important part of pathogenesis in RAU. CMV infection may be an important factor resulting in the disorder of cellular immunity because of the imbalance of T lymphocyte subsets.

Culturally appropriate nutrition education improves infant feeding and growth in rural Sichuan, China

Chinese studies indicate that the growth of rural infants and children lags behind that of their urban counterparts after 4 mo of age and that the gap is widening. However, the rural areas are home to >85% of China's 300 million children. Clearly, culturally appropriate rural complementary feeding interventions are needed to close the growth and health gaps. After a 1990 survey of infants in rural Sichuan confirmed that poor infant feeding practices rather than inadequate household food resources were responsible for the growth faltering, a year-long community-based pilot nutrition education intervention (n congruent with 250 infants each in Education and Control groups) was undertaken in four townships. The goal was to improve infant growth by improving infant feeding practices. Features of the intervention included the training and mobilizing of village nutrition educators who made monthly growth monitoring and complementary feeding counseling visits to all pregnant women and families with infants born during the intervention in the study villages. After 1 y, the Education group mothers showed significantly higher nutrition knowledge and better reported infant feeding practices than their Control group counterparts. Also, the Education group infants were significantly heavier and longer, but only at 12 mo (weight-for-age -1.17 vs. -1.93; P = 0.004; height-for-age -1.32 vs. -1.96; P = 0.022), had higher breast-feeding rates overall (83% vs. 75%; P = 0.034) and lower anemia rates (22% vs. 32%; P = 0.008) than the Control group infants. We conclude that these methods have potential for adaptation and development to other rural areas in the county, province and nation.

[Detection of Toxoplasma gondii DNA in the autopsy cases of abnormal birth and teratosis by polymerase chain reaction]

Toxoplasma gondii DNA in the autopsy tissues of 72 cases of the premature, stillbirth and congenital malformation was detected using polymerase chain reaction (PCR). The specific amplified products were found in 9 cases, i.e. one case of premature, 3 cases of stillbirth, one case of hydrocephalus and 4 cases of other teratosis. The positive rate was 12.5%. Ten control samples were negative. The results showed that Toxoplasma gondii infection was present in the disease cases. The finding indicates that the infection of Toxoplasma gondii may be one of the main causes of the abnormal birth and the congenital teratosis.

Hyphal tip growth and nuclear migration

Recent molecular and cytological studies have greatly advanced our understanding of hyphal tip growth and nuclear migration in filamentous fungi. Mutants involved in various aspects of hyphal tip growth have been isolated. Genes involved in nuclear migration continue to be identified, including putative regulators. The role of microtubules and microtubule motor proteins in hyphal tip growth has also been studied.

[Effects of nitroglycerin on nitric oxide and endothelin derived from bronchial epithelial cells and alveolar macrophages in asthma]

OBJECTIVE

To investigate the changes of nitric oxide(NO) and endothelin(ET) derived from alveolar macrophages(AM) and bronchial epithelial cells (BEC), and the influences of nitroglycerin (NTG) on ET and NO in asthma.

METHODS

BEC and AM from 15 patients with asthma exacerbation and 7 healthy control subjects were isolated and cultured for 48 hours. NO and ET levels in supernatants and expressions of iNOS-mRNA and ET-mRNA from cultured BEC and AM were examined by copper coated cadmiunm reduction, radioimmunoassay and in situ hybridization.

RESULTS

The NO level and the ET level in supernatants, and expressions of iNOS-mRNA and ET-mRNA from BEC and AM of the untreated group were higher than those of other groups (P < 0.05, respectively); The NO level from BEC and AM in supernatants of NTG pretreated group were elevated significantly and the ET level and the expression of iNOS-mRNA and ET-mRNA were lower than those of asthma untreated group (P < 0.05, respectively); The NO, ET levels and expressions of iNOS-mRNA, ET-mRNA derived from AM were higher than those derived from BEC in patients with asthma (P < 0.05, respectively); expression of iNOS-mRNA from BEC and AM were negatively correlated with the NO level in supernatants of cultured BEC and AM from the group pretreated by NTG in asthma (r = -0.60, r = -0.59; P < 0.01). While the expression of iNOS-mRNA and ET-mRNA by BEC and AM from other groups were positively correlated with the NO level and the ET level in supernatants of BEC and AM in asthma (all r > or = 0.902; P < 0.01, respectively).

CONCLUSIONS

BEC and AM from patients with asthma exacerbation secreted a large quantity of NO and ET because of the increased expressions of iNOS-mRNA and ET-mRNA; AM was the main source of elevated NO and ET in airways of patients with asthma exacerbation. NTG directly enhanced the production of NO and significantly inhibited the expression of ET-mRNA, and therefore decreased the production of ET.

p53 gene mutations in non-small cell lung cancer detected by polymerase chain reaction single-strand conformation polymorphism analysis

Mutations of the p53 tumor suppressor gene are the most frequent genetic alterations detected in human lung cancer. To assess the pathogenic significance of p53 gene alterations in Chinese non-small cell lung cancer (NSCLC), 74 paired samples of primary lung cancer and normal lung tissue far away from the cancer were analyzed for mutations of the p53 gene (exons 5-8) using exon-specific PCR, single-strand conformation polymorphism (PCR-SSCP). p53 mutations were observed in 55.4% (41/74) of the samples. No linkages were detected between the incidence of p53 mutations and histological type, lymph node metastasis, age or sex. Significant association between p53 mutations and degree of differentiation in adenocarcinomas, not in squamous cell carcinomas, was observed. The frequency of p53 mutations in smokers (65.3%) was higher than in nonsmokers (33.3%) and reached statistical significance. We also found p53 mutations in 6/7 samples which had tissue invasion and distant metastasis. These results suggest that smoking could be an important factor in lung carcinogenesis, p53 mutation is a worse prognosis indicator in adenocarcinomas and related to high aggressive behavior of human lung cancer.

Isolation of a new set of Aspergillus nidulans mutants defective in nuclear migration

In the filamentous fungus Aspergillus nidulans, nuclear migration in the germ tube is mediated by cytoplasmic dynein. We have previously reported the characterization of four nud (nuclear distribution) genes, nudA, nudC, nudF and nudG, involved in this process. The nudA and nudG genes respectively encode for the heavy chain and the 8-kDa light chain of cytoplasmic dynein. In this work, we describe an improved method for the isolation of nud mutants that has led to the identification of at least ten additional nud loci. We have cloned one of the genes, nudK, and determined that it encodes the actin-related protein Arp1, which is a component of the dynactin complex. This provides the first evidence that dynactin is involved in nuclear migration in A. nidulans.

[Preliminary application of PCR to curative effect assessment of chemotherapy against experimental acute infection of Toxoplasma gondii in mice]

Treatment with pyrimethamine and sulfamethoxazolum combination administered via intragastric route, was started 2 hours after each mouse received an intraperitoneal injection of a lethal inoculum of 5 x 10(3) tachyzoites of RH strain toxoplasma gondii and the therapy was lasted for 52 days. Combined therapy of the two drugs resulted in 83.3% survival rate in mice. PCR and the conventional mouse inoculation (MI) were compared for their validity as an curative effect assessing method. The positive rates of PCR and MI were 63.64% and 18.18%, respectively. The results suggest that PCR can be used in studies involving drug screening and curative effect assessment of anti-Toxoplasma chemotherapy in vivo. In addition, the results indicated that longer course of treatment against toxoplasmosis is required in clinical practice.

[Effects of inhalated isosorbide dinitrate on endothelin and nitric oxide and its therapeutic efficacy for experimental guinea-pigs with asthma]

To probe into the correlation between the changes of endothelin and nitric oxide in bronchial alveolar lavage fluid (BALF) and the treatment of inhaling isosorbide dinitrate on experimental guinea pigs with asthma, we divided 25 guinea pigs randomly into three groups (Control group, Asthma group, Isosorbide dinitrate group), and induced some subjects by inhalation of aerosolized ovalbumin as the model of asthma to investigate the endothelin (ET) and nitric oxide (NO) level in BALF as well as the pathological change of the respiratory tract. We found that the level of endothelin and nitric oxide in BALF were all elevated in experimental guinea pigs with asthma, but the degree of increase of NO in BALF was lower than that of ET. The NO and the ET levels in BALF were negative correlation (r = -0.8050, P < 0.01). After having been treated with aerosolized isosorbide dinitrate, the NO level in BALF was significantly elevated and the ET level in BALF was decreased in comparison with the asthma group (P < 0.001, respectively). Moreover, the eosinophile infiltration, exoserosis, and epithalaxia of the respiratory tract of the guinea-pigs were all lightened. The results suggest that inhaled isosoratory dinitrate could be used for treating asthma, and its mechanism may be elevation of NO level and decrease of ET level in BALF.

Nuclear migration, nucleokinesis and lissencephaly

During the past 20 years, biologists have become used to finding that proteins first identified in simple, genetically manipulable eukaryotic organisms are conserved in higher eukaryotes. This article draws attention to the similarity between NUDF protein, which is required for nuclear migration in the filamentous fungus Aspergillus nidulans, and a mammalian homologue, LIS1, whose malfunction causes lissencephaly, a neuronal migration disease. The authors suggest that there might be an underlying similarity of mechanism between nuclear migration in the fungus and neuronal migration in the brain.

Extended-spectrum beta-lactamase-producing Klebsiella pneumoniae strains causing nosocomial outbreaks of infection in the United Kingdom

Representative isolates from 10 distinct extended-spectrum beta-lactamase-producing strains of Klebsiella pneumoniae that caused hospital outbreaks in the United Kingdom from 1991 to 1994 were examined for relationships between their enzymes and plasmids. The beta-lactamases were identified by a combination of isoelectric focusing and gene sequencing. SHV-2 beta-lactamase was produced by isolates from four outbreaks, SHV-5 was involved in three, and SHV-4, TEM-15, and TEM-26 were involved in one outbreak each. All of the extended-spectrum beta-lactamases were encoded by self-transmissible plasmids, with sizes ranging from about 70 to 160 kb. No similarities between the restriction digest patterns of the extended-spectrum beta-lactamase-encoding plasmids were detected, except to some extent between those that produced TEM-15 and TEM-26. Thus, outbreaks of hospital infection with these organisms in the United Kingdom from 1991 to 1994 involved distinct organisms and resistance plasmids and appeared to be unrelated.

[Ultrastructural pathologic research on the adult laryngeal papilloma]

In this paper, the ultrastructural features of laryngeal papillomas of 9 cases of adult patients were investigated by means of SEM. It showed that the polypoid surface of the papilloma is easily recognized; the surface cells are covered by microvilli of different size and shape; and the epithelium is bordered by an irregular and continuous basement membrane. In some areas, there is pseudopodium of basal cells stretching into connective tissue. The structure of interface between basement membrane and connective tissue varies with aggravation of tumor cell atypia. The significant variation of structural of basement membrane and semidesmosomes suggests the possibility of malignant change.

Identification of a blue photoluminescent composite material from a combinatorial library

A quaternary combinatorial masking strategy was used in conjunction with photolithography to generate compositionally diverse thin-film phosphor libraries containing 1024 different compositions on substrates 2.5 centimeters square. A parallel imaging system and scanning spectrophotometer were used to identify and characterize compositions in the library with interesting luminescent behavior. Optimal compositions were identified with the use of gradient libraries, in which the stoichiometry of a material was varied continuously. This process led to the identification of an efficient blue photoluminescent composite material, Gd3Ga5O12/SiO2. Experimental evidence suggests that luminescence in this material may arise from interfacial effects between SiO2 and Gd3Ga5O12.

Neoplastic transformation and cytogenetic aberrations of rat tracheal epithelial cells induced by alpha-particle irradiation

Primary rat tracheal epithelium (RTE) cells can be transformed in vitro by alpha-particles irradiation. One out of 3 isolated morphologically transformed colonies gave rise to an immortal cell line and ultimately became neoplastic by successive passaging. Cytogenetic analysis was performed on the cell line in order to understand how the specific chromosome alterations participate in the process of neoplastic transformation of RTE cells. The 5th, 18th, 39th passage cells and the colony cells isolated from soft agar (SA) culturing of the 40th passage cells were analyzed. The results showed that the 20th passage cells were nontumorigenic, but the 40th passage cells were tumorigenic. The increase of the length of the long arm of chromosome 15 (15q+) was frequent at the 5th passage (67.8%), especially in SA cells in which it occurred in a clonal fashion (100%). Therefore, 15q+ might be the critical gene lesion after alpha-particles irradiation. Monosomy of chromosome 8 that occurred frequently at passage 5 (54%) and 40 (53%) might be correlated with earlier transformation of RTE cells. In addition, three marker chromosomes (M1, M2 and M3) showed a passage-dependent increase. In particular M1 and M2 that were highly frequent at passage 39 (90%) suggested that they might play an important role in the process of cell transformation.

Mechanism and stability of hyperproduction of the extended-spectrum beta-lactamase SHV-5 in Klebsiella pneumoniae

Some isolates of SHV-5 beta-lactamase-producing Klebsiella pneumoniae K2 from a single-strain outbreak of cross-infection produced approximately five-fold more beta-lactamase than others. We investigated three possible genetic mechanisms of this hyperproduction: the presence of a more powerful promoter, an increase in plasmid copy number or an amplification of the gene on a plasmid. No differences between low and high beta-lactamase producers were detected in the promoter region of the SHV-5 beta-lactamase gene, which closely resembled that of SHV-2. SHV-5 beta-lactamase production was encoded on a low copy number plasmid, but DNA-DNA hybridization with an SHV-specific probe detected a higher gene dose in hyperproducers. The beta-lactamase hyperproduction was unstable on repeated subculture, with a reduction of about 75% after 100 generations. Hyperproducing mutants of a low-producing Klebsiella and its Escherichia coli K-12 transconjugants could be selected in vitro at a frequency of 10(-5) to 10(-6) and these variants had an increased SHV-5 beta-lactamase gene copy number on low copy number plasmids. We conclude that hyperproduction of the extended-spectrum beta-lactamase was caused by gene amplification that could be easily lost or gained in vitro. Since the change to hyperproduction occurred at a high frequency and hyperproducers showed increased resistance to many beta-lactams and beta-lactam/beta-lactamase inhibitor combinations, we suspect that these variants may readily be selected in patients during antibiotic therapy.

Deletion of nudC, a nuclear migration gene of Aspergillus nidulans, causes morphological and cell wall abnormalities and is lethal

Nuclear migration is required for normal development in both higher and lower eukaryotes. In fungi this process is mediated by cytoplasmic dynein. It is believed that this motor protein is anchored to the cell membrane and moves nuclei by capturing and pulling on spindle pole body microtubules. To date, four genes have been identified and shown to be required for this process in Aspergillus nidulans. The nudA and nudG genes, respectively, encode the heavy and light chains of cytoplasmic dynein, and the nudF and nudC gene products encode proteins of 49 and 22 kDa. The precise biochemical functions of the nudF and nudC genes have not yet been identified. In this report we further investigate NUDC protein function by deleting the nudC gene. Surprisingly, although deletion of nudA and nudF affect nuclear migration, deletion of nudC profoundly affected the morphology and composition of the cell wall. Spores of the strain deleted for nudC grew spherically and lysed. The thickness of the cell wall was increased in the deletion mutant and wall polymer composition was abnormal. This phenotype could be repressed by growth on osmotically buffered medium at low temperature. Similar, but less severe, effects were also noted in a strain depleted for NUDC by down-regulation. These results suggest a possible relationship between fungal cell wall biosynthesis and nuclear migration.

Association analysis of the dopamine D4 gene exon III VNTR and heroin abuse in Chinese subjects

Although social and cultural influences are clearly important, family, twin and adoption studies indicate that genes contribute significantly to substance abuse. Substance abuse is associated with novelty seeking, a heritable human personality trait which may be influenced by alleles of the dopamine D4 (DRD4) gene exon III VNTR. Consequently Kotler et al analysed the DRD4 VNTR in opiate-dependent subjects from Israel, and found a significant excess of the 7-repeat allele. We have attempted to replicate this finding using a Han Chinese case-control sample of 121 heroin-dependent subjects and 154 normal controls. We found two 7-repeat alleles which occurred exclusively in the patient group, and overall there was an excess of longer alleles, which did not reach significance (chi 2 = 7.04; P = 0.07). When the D4 VNTR was divided into 'long' (5-7 repeats) and 'short' (2-4 repeats), a significant excess of long alleles was observed in the patient group (P = 0.023, one-tailed), with an odds ratio of 2.30 (95% CI 1.07-4.93). We conclude that our findings support the hypothesis that alleles of the DRD4 exon III VNTR are susceptibility factors for heroin abuse.

Mutations in the heavy chain of cytoplasmic dynein suppress the nudF nuclear migration mutation of Aspergillus nidulans

To identify proteins that interact directly or indirectly with the NUDF protein, which is required for nuclear migration in Aspergillus nidulans, we initiated a screen for extragenic suppressors of the heat-sensitive nudF6 mutation. Suppressor mutations in at least five genes, designated snfA-snfE, caused improved growth and nuclear migration at high temperatures compared to the nudF6 parent. Two snfC mutations mapped near the nudA gene, which encodes the cytoplasmic dyncin heavy chain, and could be repaired by transformation with wild-type nudA DNA, demonstrating that they are mutations in nudA. The snfC mutations are bypass suppressors of nudF and genetic evidence indicated that NUDA and NUDF act in the same nuclear migration pathway. Taken together, our data suggests that NUDF affects nuclear migration by acting on the dynein motor system.

A prolactin-inducible T cell gene product is structurally similar to the Aspergillus nidulans nuclear movement protein NUDC

Clone 15 (c15) was originally identified as a PRL-inducible gene in activated T cells. Sequence analysis of c15 revealed that the last 94 amino acids of c15 are 68% identical and 78% similar to the filamentous fungus Aspergillus nidulans nuclear movement protein NUDC. The identification of the mammalian (rat) c15 protein suggests that the carboxy-terminal NUDC-like region has been conserved over evolution for an important structure and/or function. To determine whether c15 is functionally analogous to NUDC, complementation studies were performed using the inducible/repressible pAL5 vector system. The results of the complementation experiments show that the full-length mammalian c15 protein is not only capable of rescuing the nuclear movement defect of the nudC3 mutants, but is also able to restore the expression of the downstream endogenous NUDF protein to near wild type levels. These results indicate that rat c15 and fungal NUDC not only share similar structures, but also serve similar functions. Taken together, the structural and functional conservation between c15 and NUDC is consistent with the notion that c15 is the rat homolog of nudC and has therefore been given the name RnudC.

[Obstetric quality investigation on urban and rural area in China]

OBJECTIVE

A survey on implementing the proclamation in "National plan of action for the survival, protection and development of children in 1990s" in China (NPA), by reducing the maternal mortality rate (MMR) by half and the infant mortality rate (IMR) by 1/3 by the year 2000 as a proof of improved obstetric quality.

METHOD

The maternal and child health (MCH) bureau, ministry of health, have called on a cooperative investigation on obstetric quality in 75 obstetric clinics in 11 provinces, municipalities or autonomous regions, randomly sampled from each of the 6 governmental areas in China. The data were collected and analyzed centrally, together with the yearly reports from the monitored county hospitals.

RESULTS

Senior medical professionals associated to 32.68% in provincial and teaching hospitals while only 2.63% in the country hospitals. The former are provided with all necessary equipment while the latter with inadequate and outdated ones. MMR declined year by year, more marked wherever hospital delivery rate was high and when the numbers of antenatal visit were more. However, when antenatal visit began late in pregnancy, MMR rose Zhejiang province and Shanghai ranked first in obstetric quality because of an efficient systematic management of the pregnancies.

CONCLUSIONS

Having enough leading professionals in this specialty to train adequate medical ground personnel at grass root level; providing sufficient medical installations; enforcing easily and good quality antenatal care and increasing hospital deliveries carried out under authoritative management are important points to raise the quality of obstetrics.

Mapping 638 STSs to regions of human chromosome 3

The initial step of mapping STSs to chromosome 3 has been by mapping to a reference panel of 21 somatic cell hybrids containing fragments of chromosome 3. In this study we map 638 STSs to 23 bins on chromosome 3. The bin information greatly facilitates further mapping by radiation hybrids and YAC clones.

An alpha tubulin mutation suppresses nuclear migration mutations in Aspergillus nidulans

Microtubules and cytoplasmic dynein, a microtubule-dependent motor, are required for nuclei to move along the hyphae of filamentous fungi. Nuclear migration in Aspergillus nidulans is blocked by heat-sensitive (hs-) mutations in the nudA gene, which encodes dynein heavy chain, and the nudF gene, which encodes a G protein beta-subunit-like protein. Hs- mutations in the nudC and nudG genes also prevent nuclear migration. We have isolated extragenic suppressor mutations that reverse the hs- phenotypes caused by these mutations. Here we show that one nudF suppressor also suppresses hs- mutations in nudA, nudC, and nudG and deletions in nudA and nudF. This suppressor mutation is in the tubA alpha tubulin gene, and its characteristics suggest that it destabilizes microtubules. The mutation alters microtubule staining and confers sensitivity to cold and benomyl, two treatments that destabilize microtubules. Treatment with low concentrations of benomyl also suppresses the hs- nudA, nudC, nudF, and nudG mutations and the nudA and nudF deletions. Suppression of the hs- nudA mutation and the nudA deletion is especially interesting because these strains lack active dynein heavy chain. Together, these results suggest that microtubule destabilization allows nuclei to migrate even in the absence of cytoplasmic dynein motor function.

Characterization and localization of the cytoplasmic dynein heavy chain in Aspergillus nidulans

Migration of nuclei throughout the mycelium is essential for the growth and differentiation of filamentous fungi. In Aspergillus nidulans, the nudA gene, which is involved in nuclear migration, encodes a cytoplasmic dynein heavy chain. In this paper we use antibodies to characterize the Aspergillus cytoplasmic dynein heavy chain (ACDHC) and to show that the ACDHC is concentrated at the growing tip of the fungal mycelium. We demonstrate that four temperature-sensitive mutations in the nudA gene result in a striking decrease in ACDHC protein. Cytoplasmic dynein has been implicated in nuclear division in animal cells. Because the temperature-sensitive nudA mutants are able to grow slowly with occasional nuclei found in the mycelium and are able to undergo nuclear division, we have created a deletion/disruption nudA mutation and a tightly downregulated nudA mutation. These mutants exhibit a phenotype very similar to that of the temperature-sensitive nudA mutants with respect to growth, nuclear distribution, and nuclear division. This suggests that there are redundant backup motor proteins for both nuclear migration and nuclear division.