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51.
52.
JOSIANE ETANG† JOSE L. VICENTE‡ PHILIPPE NWANE§ MOUHAMADOU CHOUAIBOU§ ISABELLE MORLAIS¶ VIRGILIO E. DO ROSARIO‡ FREDERIC SIMARD¶ PARFAIT AWONO-AMBENE JEAN CLAUDE TOTO JOAO PINTO‡ 《Molecular ecology》2009,18(14):3076-3086
Sequence variation at the intron-1 of the voltage-gated sodium channel gene in Anopheles gambiae M- and S-forms from Cameroon was assessed to explore the number of mutational events originating knockdown resistance ( kdr ) alleles. Mosquitoes were sampled between December 2005 and June 2006 from three geographical areas: (i) Magba in the western region; (ii) Loum, Tiko, Douala, Kribi, and Campo along the Atlantic coast; and (iii) Bertoua, in the eastern continental plateau. Both 1014S and 1014F kdr alleles were found in the S-form with overall frequencies of 14% and 42% respectively. Only the 1014F allele was found in the M-form at lower frequency (11%). Analysis of a 455 bp region of intron-1 upstream the kdr locus revealed four independent mutation events originating kdr alleles, here named MS1 -1014F, S1-1014S and S2-1014S kdr- intron-1 haplotypes in S-form and MS3-1014F kdr- intron-1 haplotype in the M-form. Furthermore, there was evidence for mutual introgression of kdr 1014F allele between the two molecular forms, MS1 and MS3 being widely shared by them. Although no M/S hybrid was observed in analysed samples, this wide distribution of haplotypes MS1 and MS3 suggests inter-form hybridizing at significant level and emphasizes the rapid diffusion of the kdr alleles in Africa. The mosaic of genetic events found in Cameroon is representative of the situation in the West–Central African region and highlights the importance of evaluating the spatial and temporal evolution of kdr alleles for a better management of insecticide resistance. 相似文献
53.
On importance resampling for the bootstrap 总被引:1,自引:0,他引:1
54.
Short-term primary culture of acinar-intercalated duct complexes from rat submandibular glands 总被引:7,自引:0,他引:7
David O. Quissell Robert S. Redman Marvin R. Mark 《In vitro cellular & developmental biology. Plant》1986,22(8):469-480
Summary Acinar-intercalated duct complexes dissociated from rat submandibular glands have been shown to be an excellent model for
studying secretory responses of salivary gland components. However, they are functionally normal for only a few hours. We
undertook a systematic manipulation of primary culture conditions in an attempt to extend the useful life of the complexes.
The major modifications that were tested were increased oxygenation in increments to 95%; substitution of norepinephrine or
carbamylcholine or both for isoproterenol in the medium; different sources of collagen for and addition of laminin, fibronectin
and/or type IV collagen to the matrix gel; and varying the thickness of the collagen gel, richness of the cell suspension
inoculate, and sources and concentrations of sera in the medium. Progress was monitored by light microscopic evaluation of
routine sections of specimens until improved maintenance of acinar and other cells warranted carrying parallel cultures for
biochemical, histochemical, and ultrastructural analyses. Best results were obtained with 90% O2, laminin in rat tail collagen gel, 10% fetal bovine serum, and 3 μM isoproterenol. Morphologically, there was good survival of acini and intercalated ducts after 1 d, with decreased acinar
size being correlated with secretory response to the isoproterenol. Reorganization and considerable mitotic activity were
seen at 2, 3, and 4 d, with most clusters of cells becoming much larger than the original complexes. During this period acinar
cells steadily became less differentiated and their numbers decreased in proportion to intercalated duct or undifferentiated
cells. However, there was good overall survival through 7 d. Biochemical analysis indicated that the cells were able to maintain
significant biosynthetic activity for 4 d, with DNA, RNA, protein, and glycoprotein synthetic rates increasing over the culture
period, but the secretory capacity of the cells diminished during the primary culture period, with mucin biosynthesis and
secretion decreasing significantly after 1 d in culture.
This work was supported by a grant from the Thrasher Research Fund, by Grant AM 33835 from the National Institutes of Health,
Bethesda MD, and by the Medical Research Service of the Veterans Administration, Washington, D.C. 相似文献
55.
YONGLIANG LI MARIE-JEANNE MARION MARINA ASHEROVA DRISSA COULIBALY STEVEN J. SMITH TAMARA DO 《Biomarkers》2013,18(6):433-439
The production of mutations in cellular oncogenes such as ras is involved in the development of many human cancers. These mutations result in the expression of mutant forms of the encoded p21 protein which can potentially serve as a biomarker for this carcinogenic process. Workers exposed to vinyl chloride (VC) who are at risk for the development of the sentinel neoplasm angiosarcoma of the liver (ASL) represent a model population for the study of such a mutant p21ras biomarker, since VC is known to cause a specific ras mutation in ASL. In order to determine the relationship between VC exposure and this biomarker, serum samples from a cohort of 225 French VC workers and 111 age-sex-race-smoking-drinking matched unexposed controls were examined for the presence of mutant p21ras by immunoblotting with a mouse monoclonal antibody specific for the mutant protein. Stratifying the exposed workers by degree of VC exposure in estimated ppm-years by quartiles yielded a statistically significant trend for increasing odds ratio for sero-positivity of the p21ras biomarker with increasing exposure. These results suggest that this serum biomarker is related to VC exposure and may be an early indicator of carcinogenic risk in exposed individuals. 相似文献
56.
S M Anderson M E Reyland S Hunter L M Deisher K A Barzen D O Quissell 《Cell death and differentiation》1999,6(5):454-462
We have examined the ability of etoposide to induce apoptosis in two recently established rat salivary acinar cell lines. Etoposide induced apoptosis in the parotid C5 cell line as evidenced by the appearance of cytoplasmic blebbing and nuclear condensation, DNA fragmentation and cleavage of PARP. Etoposide also induced activation of c-jun N-terminal kinase (JNK) in parotid C5 cells by 4 h after treatment, with maximal activation at 8 - 10 h. Coincident with activation of JNK, the amount of activated ERK1 and ERK2 decreased in etoposide-treated parotid C5 cells. In contrast to the parotid C5 cells, the vast majority of submandibular C6 cells appeared to be resistant to etoposide-induced apoptosis. Likewise, activation of JNKs was not observed in etoposide-treated submandibular C6 cells, and the amount of activated ERK1 and ERK2 decreased only slightly. Etoposide treatment of either cell line had no effect upon the activation of p38. Treatment of the parotid C5 cells with Z-VAD-FMK, a caspase inhibitor, inhibited etoposide-induced activation of JNK and DNA fragmentation. These data suggest that etoposide may induce apoptosis in parotid C5 cells by activating JNKs and suppressing the activation of ERKs, thus creating an imbalance in these two signaling pathways. 相似文献
57.
David O. Quissell Robert S. Redman Katherine A. Barzen Rodney L. McNutt 《In vitro cellular & developmental biology. Animal》1994,30(12):833-842
Summary The objective of these studies was to develop serum-free culture conditions for dissociated acini from rat submandibular glands.
Acini were isolated from the submandibular glands of 42–46 d old rats and cultured on reconstituted rat tail collagen containing
laminin in 1:1 Ham’s F12 and Dulbecco’s media, supplemented with BSA, transferrin, insulin, T3, EGF, dexamethasone, retinoic acid, carbamylcholine, and trace elements, and gassed with 50% O2. The acini became partly embedded in the collagen gel and rapidly enlarged throughout the first 22 d of culture, maintaining
modest seromucous acinar differentiation, as judged morphologically and by mucin secretion. Parallel cultures then were grown
under 20, 35, 50, and 65% O2, and evaluated morphologically and by DNA content. Growth and retention of seromucous acinar characteristics were best with
35% O2, but lipid accumulation and cell death were unacceptably high. A spectrum of concentrations of insulin and glucagon then
were tried. With 0.05μg/ml insulin, cellular growth and organization were orderly, lipid accumulations were not excessive, and moderate differentiation
was retained through 15 d of culture. With more than 0.1μg/ml insulin added to or subtracted from the optimum, the detrimental effects recurred. Addition of sufficient glucagon counteracted
the effects of both optimum and excessive concentrations of insulin. We now have achieved an orderly growth of moderately
differentiated rat submandibular acini for 15 d in serum-free primary culture. 相似文献
58.
ADRIAN A. BARNETT SARAH A. BOYLE MARILYN M. NORCONK SUZANNE PALMINTERI RICARDO R. SANTOS LIZA M. VEIGA THIAGO H.G. ALVIM MARK BOWLER JANICE CHISM ANTHONY DI FIORE EDUARDO FERNANDEZ‐DUQUE ANA C. P. GUIMARÃES AMY HARRISON‐LEVINE TORBJØRN HAUGAASEN SHAWN LEHMAN KATHERINE C. MACKINNON FABIANO R. DE MELO LEANDRO S. MOREIRA VIVIANE S. MOURA CARSON R. PHILLIPS LILIAM P. PINTO MARCIO PORT‐CARVALHO ELEONORE Z. F. SETZ CHRISTOPHER SHAFFER LÍVIA RODRIGUES DA SILVA SULEIMA DO S. B. DA SILVA RAFAELA F. SOARES CYNTHIA L. THOMPSON TATIANA M. VIEIRA ARIOENE VREEDZAAM SUZANNE E. WALKER‐PACHECO WILSON R. SPIRONELLO ANN MACLARNON STEPHEN F. FERRARI 《American journal of primatology》2012,74(12):1106-1127
Neotropical monkeys of the genera Cacajao, Chiropotes, and Pithecia (Pitheciidae) are considered to be highly arboreal, spending most of their time feeding and traveling in the upper canopy. Until now, the use of terrestrial substrates has not been analyzed in detail in this group. Here, we review the frequency of terrestrial use among pitheciin taxa to determine the ecological and social conditions that might lead to such behavior. We collated published and unpublished data from 14 taxa in the three genera. Data were gleaned from 53 published studies (including five on multiple pitheciin genera) and personal communications of unpublished data distributed across 31 localities. Terrestrial activity was reported in 61% of Pithecia field studies (11 of 18), in 34% of Chiropotes studies (10 of 29), and 36% of Cacajao studies (4 of 11). Within Pithecia, terrestrial behavior was more frequently reported in smaller species (e.g. P. pithecia) that are vertical clingers and leapers and make extensive use of the understory than in in the larger bodied canopy dwellers of the western Amazon (e.g. P. irrorata). Terrestrial behavior in Pithecia also occurred more frequently and lasted longer than in Cacajao or Chiropotes. An apparent association was found between flooded habitats and terrestrial activity and there is evidence of the development of a “local pattern” of terrestrial use in some populations. Seasonal fruit availability also may stimulate terrestrial behavior. Individuals also descended to the ground when visiting mineral licks, escaping predators, and responding to accidents such as a dropped infant. Overall, the results of this review emphasize that terrestrial use is rare among the pitheciins in general and is usually associated with the exploitation of specific resources or habitat types. Am. J. Primatol. 74:1106‐1127, 2012. © 2012 Wiley Periodicals, Inc. 相似文献
59.
60.
David O. Quissell Katherine A. Barzen Lynn M. Deisher 《Biochimica et Biophysica Acta (BBA)/Molecular Cell Research》1983,762(2):215-220
The extent of activation of rat submandibular gland cyclic AMP-dependent protein kinase (EC 2.7.1.37) was determined in vitro using dispersed cells to assess the involvement of this enzyme in submandibular mucin secretion. cAMP-dependent protein kinase activation, as determined by activity ratio method, was markedly increased following β-adrenergic receptor activation. 0.5 M NaCl was required in the homogenization buffer for stabilization of the hormonally activated cAMP-dependent protein kinase. A role for cAMP-dependent protein kinase activation in regulating mucin secretion was strongly suggested by the following: (1) the kinase activity ratio increased rapidly after β-adrenergic receptor stimulation; (2) dose-response relationship of the kinase activation following β-adrenergic receptor activation correlated with isoproterenol induced mucin release; (3) termination of β-adrenergic mediated mucin secretion caused a rapid decrease in the kinase activity ratio; (4) dibutyryl cyclic AMP stimulation caused an increase in the kinase ratio; whereas (5) pure cholinergic and pure α-adrenergic receptor stimulation had no effect on endogenous kinase activity. Although cAMP-dependent protein kinase activation may not be the only regulator of mucin secretion, these data suggest an important regulatory role for this kinase activation during rat submandibular mucin release. 相似文献