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101.
ABSTRACT Pre-treatment of seeds of Tamarindus indica L. with 95% sulphuric acid for 5, 10 or 15 min, methanol, ethanol, iso-propanol or butanol for 10 or 20 min, or boiling water for 10, 15, 20 or 30 min, was used to determine the effect of the various treatments on the development and vigour of the resultant seedlings. Seeds immersed in methanol, ethanol and sulphuric acid for 10 min produced seedlings with high vigour 相似文献
102.
103.
In previous investigations, steroid 21-hydroxylase activity was demonstrated in human fetal kidney, thymus, and spleen tissues. In the present investigation, steroid 17 alpha-hydroxylase activity also was found in microsome-enriched preparations of human fetal kidney, thymus, and spleen tissues. 相似文献
104.
The molecular order of brain and liver membranes isolated from deep sea and continental shelf fish species have been estimated and compared using the fluorescence polarization technique in order to determine whether life in a high pressure habitat is associated with an adjustment of membrane order. Fish were trawled at depths between 200 m and 4000 m, liver and brain membranes were fractionated, and fluorescence polarization was measured at 4°C and ambient pressure. Polarization of the brain myelin fraction provided a statistically significant regression with depth of capture () with a slope of ?0.004 km?1. This change in polarization with depth was sufficient to offset approximately half of the pressure-induced increase in polarization and thus represents the first structural evidence of homeoviscous adaptation to pressure. Polarization of the brain synaptic and liver mitochondrial fraction was not significantly related to depth. This may be due, at least in part, to a high individual variability of polarization compared to laboratory-acclimated freshwater fish. 相似文献
105.
Andrew J. MacDonald Sofie McComb Craig ONeill Kerry A. Padgett Ashley E. Larsen 《Global Change Biology》2020,26(10):5459-5474
Global environmental change is having profound effects on the ecology of infectious disease systems, which are widely anticipated to become more pronounced under future climate and land use change. Arthropod vectors of disease are particularly sensitive to changes in abiotic conditions such as temperature and moisture availability. Recent research has focused on shifting environmental suitability for, and geographic distribution of, vector species under projected climate change scenarios. However, shifts in seasonal activity patterns, or phenology, may also have dramatic consequences for human exposure risk, local vector abundance and pathogen transmission dynamics. Moreover, changes in land use are likely to alter human–vector contact rates in ways that models of changing climate suitability are unlikely to capture. Here we used climate and land use projections for California coupled with seasonal species distribution models to explore the response of the western blacklegged tick (Ixodes pacificus), the primary Lyme disease vector in western North America, to projected climate and land use change. Specifically, we investigated how environmental suitability for tick host‐seeking changes seasonally, how the magnitude and direction of changing seasonal suitability differs regionally across California, and how land use change shifts human tick‐encounter risk across the state. We found vector responses to changing climate and land use vary regionally within California under different future scenarios. Under a hotter, drier scenario and more extreme land use change, the duration and extent of seasonal host‐seeking activity increases in northern California, but declines in the south. In contrast, under a hotter, wetter scenario seasonal host‐seeking declines in northern California, but increases in the south. Notably, regardless of future scenario, projected increases in developed land adjacent to current human population centers substantially increase potential human–vector encounter risk across the state. These results highlight regional variability and potential nonlinearity in the response of disease vectors to environmental change. 相似文献
106.
Rufus M. G. Wells Heather McNeil John A. MacDonald 《Marine and Freshwater Behaviour and Physiology》2013,45(1):71-78
An immobility reflex may be induced in fish by a vigorous flow of water through the branchial chamber. The reflex was observed in 22 species representing bony and cartilaginous fishes from diverse habitats, and was invariably characterised by loss of caudal muscle tone and limp posture. The immobilised state may be maintained for many hours, and revival is instantaneous. The critical flow rate for induction increases with increasing body size in the snapper, Pagrus auratus, and heart rate falls below the resting rate. In addition, haematological parameters, and plasma lactate after 6?h were typical of resting fish. Although the mechanism is unclear, and the selective advantage for the fish unknown, pressure-sensitive receptors in the branchial chamber are likely to be involved. Application in live fish transport, and recovery from handling and exercise stressors is suggested. 相似文献
107.
JA Kiernan 《Biotechnic & histochemistry》2013,88(5-6):203-210
Hexazonium pararosaniline is a valuable reagent that has been used in enzyme activity histochemistry for 50 years. It is an aqueous solution containing the tris-diazonium ion derived from pararosaniline, an aminotriarylmethane dye, and it contains an excess of nitrous acid that was not consumed in the diazotization reaction. Other investigators have found that immersion for 2 min in an acidic (pH 3.5) 0.0015 M hexazonium pararosaniline solution can protect cryostat sections of unfixed animal tissues from the deleterious effects of aqueous reagents such as buffered solutions used in immunohistochemistry, while preserving specific affinities for antibodies. In the present investigation hexazonium pararosaniline protected lymphoid tissue and striated muscle against the damaging effects of water or saline. The same protection was conferred on unfixed sections treated with dilute nitrous or hydrochloric acid in concentrations similar to those in hexazonium pararosaniline solutions. Model tissues (solutions, gels or films containing gelatin and/or bovine albumin) responded predictably to well known cross-linking (formaldehyde) or coagulant (mercuric chloride) fixatives. Hexazonium pararosaniline solutions prevented the dissolution of protein gels in water only after 9 or more days of contact, during which time considerable swelling occurred. It is concluded that there is no evidence for a “fixative” action of hexazonium pararosaniline. The protective effect on frozen sections of unfixed tissue is attributable probably to the low pH of the solution. 相似文献
108.
109.
Michael J. J. Chu Anthony R. J. Phillips Alexander W. G. Hosking Julia R. MacDonald Adam S. J. R. Bartlett Anthony J. R. Hickey 《PloS one》2013,8(10)
Backgrounds and Aim
Current assessment of pre-operative liver function relies upon biochemical blood tests and histology but these only indirectly measure liver function. Mitochondrial function (MF) analysis allows direct measurement of cellular metabolic function and may provide an additional index of hepatic health. Conventional MF analysis requires substantial tissue samples (>100 mg) obtained at open surgery. Here we report a method to assess MF using <3 mg of tissue obtained by a Tru-cut® biopsy needle making it suitable for percutaneous application.Methods
An 18G Bard® Max-core® biopsy instrument was used to collect samples. The optimal Tru-cut® sample weight, stability in ice-cold University of Wisconsin solution, reproducibility and protocol utility was initially evaluated in Wistar rat livers then confirmed in human samples. MF was measured in saponin-permeabilized samples using high-resolution respirometry.Results
The average mass of a single rat and human liver Tru-cut® biopsy was 5.60±0.30 and 5.16±0.15 mg, respectively (mean; standard error of mean). Two milligram of sample was found the lowest feasible mass for the MF assay. Tissue MF declined after 1 hour of cold storage. Six replicate measurements within rats and humans (n = 6 each) showed low coefficient of variation (<10%) in measurements of State-III respiration, electron transport chain (ETC) capacity and respiratory control ratio (RCR). Ischemic rat and human liver samples consistently showed lower State-III respiration, ETC capacity and RCR, compared to normal perfused liver samples.Conclusion
Consistent measurement of liver MF and detection of derangement in a disease state was successfully demonstrated using less than half the tissue from a single Tru-cut® biopsy. Using this technique outpatient assessment of liver MF is now feasible, providing a new assay for the evaluation of hepatic function. 相似文献110.
Felicia M. Wagner Ilija Brizic Adrian Prager Tihana Trsan Maja Arapovic Niels A. W. Lemmermann Jürgen Podlech Matthias J. Reddehase Frederic Lemnitzer Jens Bernhard Bosse Martina Gimpfl Lisa Marcinowski Margaret MacDonald Heiko Adler Ulrich H. Koszinowski Barbara Adler 《PLoS pathogens》2013,9(7)
Human cytomegalovirus (HCMV) forms two gH/gL glycoprotein complexes, gH/gL/gO and gH/gL/pUL(128,130,131A), which determine the tropism, the entry pathways and the mode of spread of the virus. For murine cytomegalovirus (MCMV), which serves as a model for HCMV, a gH/gL/gO complex functionally homologous to the HCMV gH/gL/gO complex has been described. Knock-out of MCMV gO does impair, but not abolish, virus spread indicating that also MCMV might form an alternative gH/gL complex. Here, we show that the MCMV CC chemokine MCK-2 forms a complex with the glycoprotein gH, a complex which is incorporated into the virion. We could additionally show that mutants lacking both, gO and MCK-2 are not able to produce infectious virus. Trans-complementation of these double mutants with either gO or MCK-2 showed that both proteins can promote infection of host cells, although through different entry pathways. MCK-2 has been extensively studied in vivo by others. It has been shown to be involved in attracting cells for virus dissemination and in regulating antiviral host responses. We now show that MCK-2, by forming a complex with gH, strongly promotes infection of macrophages in vitro and in vivo. Thus, MCK-2 may play a dual role in MCMV infection, as a chemokine regulating the host response and attracting specific target cells and as part of a glycoprotein complex promoting entry into cells crucial for virus dissemination. 相似文献