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101.
Multiple shoots were obtained from nodal and shoot tip segments of 10 to 15-day-old seedlings of Syzygium cuminii L. on Murashige & Skoog (MS) revised medium supplemented with 6-benzyladenine (BA) (0.23–8.90 M) singly or in combination with -naphthaleneacetic acid (NAA), indole-3-acetic acid (IAA) or indole-3-butyric acid (IBA). Excised shoots were placed for root induction on MS medium containing NAA and/or IBA and then transferred to MS basal medium to form complete plantlets. The regenerated plantlets have been acclimatized and successfully transferred into the soil. 相似文献
102.
Genomic DNA blot analyses using probes derived from the BALB/c 3 flanking region of the L
d gene (L
d 3 fl-C) and from near the BALB/c D3
d gene (50.2A) indicate that the B10.GAA37 mouse strain has a multi-locus D (D
w16) region distinct from the five-gene organization observed in the D
d and D
q regions. To isolate the D
w16 region class I genes, a genomic B10. GAA37-EMBL3 library was generated and screened with probes that preferentially hybridize to K and D region class I genes. Hybridization analyses of the isolated clones with L
d derived oligonucleotide probes suggested that one of the clones contained the L
w16 gene, whereas several other clones contained the L
w16 gene. The sequence of the D
w16 gene is most similar to that of the D
p gene, particularly in the 3 half. Furthermore, the L
w16 gene is quite similar in the 5 half and virtually identical in the 3 half to the L
d gene, indicating that L
w16, but not D
w16, is a member of the L
d gene family. Collectively, these data suggest that, through a D region recombination event, the novel D
w16 region may have been assembled from primordial counterparts of the D
p and L
d genes.The nucleotide sequence data reported in this paper have been submitted to the GenBank nucleotide sequence database and have been assigned the accession number M60774-M60776, and M62759. 相似文献
103.
To study the dynamics of peptide groups in solid proteins, we have accurately determined the principal components and molecular orientation of the electric field gradient tensor for the exchangeable deuterons in monoclinic N-acetylglycine by single-crystal deuterium nuclear magnetic resonance. These results are compared with the principal components of the amide deuterons in solid poly(gamma-benzyl-L-glutamate) measured in powder samples over a wide temperature range (140-400 K). The comparison indicates that in the solid polypeptide the N-D bonds undergo a small-amplitude torsional reorientation (libration) perpendicular to the peptide plane. To estimate dynamic rates, longitudinal relaxation times (T1 values) are reported for N-acetylglycine and poly(gamma-benzyl-L-glutamate). T1 values for the carboxyl and amide deuterons in N-acetylglycine are approximately 100 s, whereas for the amide deuterons in the polypeptide T1 approximately 1 s, also indicating that the N-D bonds are not stationary in the polypeptide. We determine from the reduced quadrupole coupling tensor the mean-square amplitude for the libration and show that it increases linearly with temperature. A simple qualitative theory for the relaxation times is presented on the basis of the assumption that the N-D reorientation is described either as a diffusion process in a square well or as a damped Langevin oscillator with a harmonic restoring force. The conclusion is that the short relaxation times of the polypeptide amide deuterons result from substantial frictional effects on reorientation that increase with temperature. 相似文献
104.
Initiation of Antiviral B Cell Immunity Relies on Innate Signals from Spatially Positioned NKT Cells
Mauro Gaya Patricia Barral Marianne Burbage Shweta Aggarwal Beatriz Montaner Andrew Warren Navia Malika Aid Carlson Tsui Paula Maldonado Usha Nair Khader Ghneim Padraic G. Fallon Rafick-Pierre Sekaly Dan H. Barouch Alex K. Shalek Andreas Bruckbauer Jessica Strid Facundo D. Batista 《Cell》2018,172(3):517-533.e20
105.
Memory and Learning Dysfunction Following Copper Toxicity: Biochemical and Immunohistochemical Basis
Jayantee Kalita Vijay Kumar Usha K. Misra Himangsu K. Bora 《Molecular neurobiology》2018,55(5):3800-3811
The prototype disease of Cu toxicity in human is Wilson disease, and cognitive impairment is the presenting symptom of it. There is no study correlating Cu-induced excitotoxicity, apoptosis, and astrocytic reaction with memory dysfunction. We report excitotoxicity, apoptosis, and astrocytic reaction of the hippocampus and frontal cortex with memory dysfunction in rat model of Cu toxicity. Thirty-six rats were divided into group I (control) and group II (100 mg/kgBwt/day CuSO4 orally). Y-maze was performed for memory and learning at 0, 30, 60, and 90 days. Frontal and hippocampal free Cu concentration, oxidative stress markers [glutathione (GSH), total antioxidant toxicity (TAC), and malondialdehyde (MDA)], and glutamate were measured by atomic absorption spectroscopy, spectrophotometry, and ELISA, respectively. N-methyl-d-aspartate receptors (NMDARs) NR1, NR2A, and NR2B were done by real-time polymerase chain reaction. Immunohistochemistry for caspase-3 and glial fibrillary acidic protein (GFAP) were done and quantified using the ImageJ software. The glutamate level in hippocampus was increased, and NMDAR expression was decreased at 30, 60, and 90 days in group II compared to group I. In the frontal cortex, glutamate was increased at 90 days, but NMDARs were not significantly different in group II compared to group I. Caspase-3 and GFAP expressions were also higher in group II compared to group I, and these changes were more marked in hippocampus than frontal cortex. These changes correlated with respective free tissue Cu, oxidative stress, and Y-maze attention score. Cu toxicity induces apoptosis and astrocytosis of the hippocampus and frontal cortex through direct or glutamate and oxidative stress pathways, and results in impaired memory and learning. 相似文献
106.
S. J. S. Flora S. N. Dube Usha Arora G. M. Kannan M. K. Shukla P. R. Malhotra 《Biometals》1995,8(2):111-116
The therapeutic efficacy of two thiol chelators, meso 2,3-dimercaptosuccinic acid (DMSA) or 2,3-dimercaptopropane sulfonate (DMPS) in treating chronic arsenic intoxication was investigated in male rats. Both the chelators were effective in promoting urinary arsenic excretion and restoring arsenic induced inhibition of blood -aminolevulinic acid dehydratase activity and hepatic glutathione level. Elevation of urinary -aminolevulinic acid excretion and arsenic concentration in blood, liver and kidneys were reduced significantly by both the chelators. Histopathological lesions induced by arsenic were also effectively reduced by the above chelators. DMSA being more effective than DMPS. The results suggest DMSA and DMPS to be effective antidotes for treating chronic arsenic toxicity in experimental animals. 相似文献
107.
108.
109.
Donald C. Malins Bruce B. McCain Donald W. Brown Usha Varanasi Margaret M. Krahn Mark S. Myers Sin-Lam Chan 《Hydrobiologia》1987,149(1):67-74
High concentrations of chemicals have been found in sediments from urban areas of Puget Sound. Hundreds, of organic chemicals (including certain aromatic hydrocarbons [AHs] and various chlorinated compounds) were identified. Statistical methods were used to evaluate possible relationships between the chemistry data and fish diseases. Positive correlations were found between the frequencies of liver neoplasms (e.g., hepatocellular carcinoma) and other liver lesions in English sole (Parophrys vetulus) and concentrations of AHs in sediment; such correlations were not found with chlorinated hydrocarbons. Strong evidence was also obtained to show that many organic chemicals in sediment are bioavailable to bottom-dwelling fish. Stomach contents (consisting mainly of benthic invertebrates) from English sole had concentrations of a number of AHs similar to those in the sediment from which the fish were taken. In these same fish, metabolites of many aromatic compounds were found in bile using a procedure combining HPLC with fluorescence detection. Further, the concentrations of certain xenobiotic metabolites in bile were correlated positively with the occurrence of liver neoplasms in English sole. 相似文献
110.