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51.
52.
Aaren S. Freeman Alejandro Frischeisen April MH. Blakeslee 《Biological invasions》2016,18(6):1653-1665
Interactions between anthropogenic disturbances and introduced and native species can shift ecological communities, potentially leading to the successful establishment of additional invaders. Since its discovery in New Jersey in 1988, the Asian shore crab (Hemigrapsus sanguineus) has continued to expand its range, invading estuarine and coastal habitats in eastern North America. In estuarine environments, H. sanguineus occupies similar habitats to native, panopeid mud crabs. These crabs, and a variety of fouling organisms (both NIS and native), often inhabit man-made substrates (like piers and riprap) and anthropogenic debris. In a series of in situ experiments at a closed dock in southwestern Long Island (New York, USA), we documented the impacts of these native and introduced crabs on hard-substrate fouling communities. We found that while the presence of native mud crabs did not significantly influence the succession of fouling communities compared to caged and uncaged controls, the presence of introduced H. sanguineus reduced the biomass of native tunicates (particularly Molgula manhattensis), relative to caged controls. Moreover, the presence of H. sanguineus favored fouling communities dominated by introduced tunicates (especially Botrylloides violaceous and Diplosoma listerianum). Altogether, our results suggest that H. sanguineus could help facilitate introduced fouling tunicates in the region, particularly in locations where additional solid substrates have created novel habitats. 相似文献
53.
Mandel U; Hassan H; Therkildsen MH; Rygaard J; Jakobsen MH; Juhl BR; Dabelsteen E; Clausen H 《Glycobiology》1999,9(1):43-52
Mucin-type O-glycosylation is initiated by a large family of UDP- GalNAc:
polypeptide N -acetyl-galactosaminyltransferases (GalNAc- transferases).
Individual GalNAc-transferases appear to have different functions and
Northern analysis indicates that they are differently expressed in
different organs. This suggests that O-glycosylation may vary with the
repertoire of GalNAc-transferases expressed in a given cell. In order to
study the repertoire of GalNAc-transferases in situ in tissues and changes
in tumors, we have generated a panel of monoclonal antibodies (MAbs) with
well defined specificity for human GalNAc-T1, -T2, and -T3. Application of
this panel of novel antibodies revealed that GalNAc- transferases are
differentially expressed in different cell lines, in spermatozoa, and in
oral mucosa and carcinomas. For example, GalNAc-T1 and -T2 but not -T3 were
highly expressed in WI38 cells, and GalNAc-T3 but not GalNAc-T1 or -T2 was
expressed in spermatozoa. The expression patterns in normal oral mucosa
were found to vary with cell differentiation, and for GalNAc-T2 and -T3
this was reflected in oral squamous cell carcinomas. The expression pattern
of GalNAc-T1 was on the other hand changed in tumors to either total loss
or expression in cytological poorly differentiated tumor cells, where the
normal undifferentiated cells lacked expression. These results demonstrate
that the repertoire of GalNAc-transferases is different in different cell
types and vary with cellular differentiation, and malignant transformation.
The implication of this is not yet fully understood, but it suggests that
specific changes in sites of O-glycosylation of proteins may occur as a
result of changes in the repertoire of GalNAc-transferases.
相似文献
54.
Haiying Zhou Ahmad Alhaskawi Qingrong Sun Yanzhao Dong Vishnu Goutham Kota Mohamed Hasan Abdulla Hasan Abdulla Sohaib Hasan Abdullah Ezzi Zewei Wang Hui Lu 《The Yale journal of biology and medicine》2021,94(4):613
Background: Desmoplastic small round cell tumor (DSRCT) is an aggressive malignant tumor commonly found in young men; most occurs in the abdominal cavity. Here we conducted an in-depth analysis of a pregnant patient in our hospital and explored all the case information in the literature on small round cell carcinoma of women. Case presentation: A 27-year-old pregnant woman underwent tumor resection in our hospital at 29 weeks gestational age for a large progressive shoulder lump. The postoperative pathology showed that the mass was a DSRCT. Genetic testing found no fusion gene. At 36 weeks gestation, a painful mass was found in the breast and proved to be a metastatic focus of the desmoplastic small round cell tumor. Twenty days after a successful cesarean section at 40 weeks gestation, she received the VAC-IE chemotherapy regimen, successfully completed the first course, but when awaiting the next chemotherapy, unfortunately, the patient died during follow-up due to tumor recurrence and metastasis. Conclusion: The treatment of DSRCT in pregnant women requires a multidisciplinary consultation, and the treatment and examination during pregnancy are subject to many constraints, which may have a negative impact on the patient’s prognosis. Also, a review of the literature found that there is still no standard treatment protocol for DSRCT, and its prognosis in female patients is independent of age and tissue origin. 相似文献
55.
Jabir Thajudeen Jesmi Yousuf Vipindas Puthiya Veetil Sherin Varghese Arvind Singh Mohamed Hatha Abdulla 《World journal of microbiology & biotechnology》2017,33(2):41
Microorganisms play a significant role in biogeochemical cycles, especially in the benthic and pelagic ecosystems. Role of environmental parameters in regulating the diversity, distribution and physiology of these microorganisms in tropical marine environment is not well understood. In this study, we have identified dinitrogen (N2) fixing bacterial communities in the sediments by constructing clone libraries of nitrogenase (nifH) gene from four different stations in the Cochin estuary, along the southeastern Arabian Sea. N2 fixing bacterial clones revealed that over 20 putative diazotrophs belong to alpha-, beta-, gamma-, delta- and epsilon- proteobacteria and firmicutes. Predominant genera among these were Bradyrhizobium sp. (α-proteobacteria), Dechloromonas sp. (β-proteobacteria); Azotobactor sp., Teredinibacter sp., Methylobacter sp., Rheinheimera sp. and Marinobacterium sp. (γ-proteobacteria); Desulfobacter sp., Desulfobulbus sp. and Desulfovibrio sp. (δ -proteobacteria); Arcobacter sp. and Sulfurospirillum sp. (ε-proteobacteria). Nostoc sp. was solely identified among the cyanobacterial phylotype. Nitrogen fixing Sulfate reducing bacteria (SRBs) such as Desulfobulbus sp., Desulfovibrio sp., Desulfuromonas sp., Desulfosporosinus sp., Desulfobacter sp., were also observed in the study. Most of the bacterial nifH sequences revealed that the identities of N2 fixing bacteria were less than 95% similar to that available in the GenBank database, which suggested that the sequences were of novel N2 fixing microorganisms. Shannon-Weiner diversity index of nifH gene ranged from 2.95 to 3.61, indicating an inflated diversity of N2 fixing bacteria. Canonical correspondence analysis (CCA) implied positive correlation among nifH diversity, N2 fixation rate and other environmental variables. 相似文献
56.
Actinomycetes were isolated from the indoor air of the church of Saint Katherin Monastery during different visiting hours.
Fifty air samples collected over one year by using automated air sampler were plated on four different media. The low nutrient-content
medium 1/10 SC was significantly effective in recovery of actinomycetes compared to the other formula of rich media. Average
counts of bacteria, actinomycetes and fungi were 487, 65 and 90 cfu/m3, respectively. Fifty-six morphologically different actinomycetes isolates were recovered during this study assigned into
five different genera, in addition to three unidentified isolates. Tentative identification of the isolates indicated predominance
of genus Streptomyces, representing 59% of the isolates. Isolates were screened for resistance to 11 antibiotics, antimicrobial activities towards
seven microbial strains, Growth on 12 different carbon source, acid production and pigmentation. About 77% of actinomycete
isolates were resistant to the antibiotics with different resistance patterns. 12.5% of the airborne actinomycetes exhibited
antinmicrobial activities. The isolates showed wide variation in carbon source usage. Forty percent of the isolates were able
to utilize all tested carbon sources while 80% were acid producers. Melanin production was produced by 34% of the isolates.
While 45% of the isolates were able to produce other diffusible pigments, the majority of the pigments were brown in color
however; yellow, orange and green pigments were produced by a number of isolates. The impact of these activities on the historical
objects of the church and the tourist’s health is discussed. 相似文献
57.
新疆北部森林生态系统地衣植物生活型分析 总被引:2,自引:0,他引:2
Life forms of lichen of forest ecosystem in Northern Xinjiang were researched in the Kanas National Natural Reservation Area.They have been grouped into 6 types:Epipetria,Soil-epipetria,Epiphytia arboricosa,Epiphytia moss,Epiphytis grass and Dry-radicantia,in which the species of Epiphytia arboricosa account for 36.89% of the total species in this area,the species of Epipetria for 22.33% and Epiphytia grass the least.The results show that life forms of lichem at the srea in Northem Xinjiang are relatively rich,which indicates the biodiversity characteristics of lichen. 相似文献
58.
Hesham Abdulla 《Microbial ecology》2009,58(4):753-761
Actinomycetes inhabiting granitic rocks at St. Katherine, Egypt were investigated for their bioweathering potential. Actinomycete
counts ranged between 174 and 360 colony forming units per gram. Counts were positively correlated to rock porosity (r = 0.65) and negatively correlated to rock salinity (r = −0.56). Sixty-six actinomycete isolates originating from rocks could be assigned into eight genera, with a high frequency
of Nocardioides and Streptomyces. Organic acids were produced by 97% of the isolates. Strains belonging to Actinopolyspora, Actinomadura, Kitasatospora, Nocardioides, and Kibdelosporangium showed the highest acid production indices. Representatives from all eight genera could precipitate metals Cu, Fe, Zn, Cd,
and Ag up to concentrations of 2.5 mM each. An actinomycete consortium of two Nocardioides strains and one Kibdelosporangium strain was studied for its potential to cause rock weathering in batch experiments. Results indicated a high ability of the
consortium to leach the metals Cu, Zn, and Fe up to 2.6-, 2.1-, and 1.3-fold, respectively, compared to the control after
4 weeks. The pH significantly decreased after 1 week, which was parallel to an increased release of phosphate and sulfate
reaching a 2.2- and 2.5-fold increase, respectively, compared to control. Highly significant weight loss (p = 0.005) was achieved by the consortium, indicating a potential multiple role of actinomycetes in weathering by acid production,
metal leaching, and solubilization of phosphate and sulfate. This study emphasizes the diverse and unique abilities of actinomycetes
inhabiting rock surfaces which could be of potential biotechnological applications, such as in the bioremediation of metal-contaminated
environments and metal biorecovery. 相似文献
59.
60.