Time Dependence of Aequorin-lndicated Calcium Levels in Stimulated and Unstimulated Platelets: Evidence for Multiple Aequorin Environments in Platelets

1989 ◽  
Vol 62 (04) ◽  
pp. 1094-1099 ◽  
Author(s):  
Bruce Lages ◽  
Harvey J Weiss

AbstractAequorin-induced calcium signals were examined in human unstimulated platelets and platelets stimulated with various agonists as a function of time. The total aequorin response in unstimulated platelets, obtained by Triton x-100 lysis in the presence of 1 mM Ca, decreased in a distinctly non-linear manner over 20-60 min. This decrease was slightly, but significantly, greater in platelets maintained in the continuous presence of 1 mM Ca than in platelets maintained without external Ca, and could not be accounted for completely by leakage of aequorin from the cells. Basal Ca levels in unstimulated platelets also decreased in a non-linear manner, with a similar sensitivity to the contmuous presence or absence of external Ca. These observed changes in aequorin response thus appear to be at least partially due to an mtracellular discharge of aequorin, and are therefore consistent with the view that aequorin in platelets is heterogeneously d1stnbuted among localized environments differing in Ca concentration. The aequorin signals observed initially in platelets stimulated by ADP or epinephrine were lost completely over a penod of 30-60 min in almost all cases studied, while initial rates of aggregation were either unchanged (epinephrine) or only partially decreased (ADP) over this same time period. In contrast, thrombin- and A23187-induced aequorin signals were virtualy unchanged over periods up to 90 min. Minimal changes with time also occurred in the aequorin signals induced by phorbol ester or by collagen in the presence of indomethacin. These differences in time dependence suggest that the signals generated by ADP and epinephrine may derive from different sources of aequorin than those associated with the signals induced by other agonists. Thus, differences in indicator localization may indeed contnbute to the observation of aequorin, but not quin 2/fura-2, signals following epinephrine stimulation as previously suggested, but this may not be the sole explanation for the discrepancies between these two Ca indicators seen with other agonists.

1987 ◽  
Author(s):  
B Lages ◽  
H J Weiss

The photoprotein aequorin (aeq) has been used as an indicator of intracellular calcium levels ([Ca]i) in platelets (pits). Aeq is believed to monitor aspects of [Ca]i somewhat different from those reported by quin-2, since it reports a higher basal [Ca]i than quin-2 and the presence, rather than the absence, of increased [Ca]i following epinephrine (epi) stimulation. To characterize further aeq-indicated pit Ca signals we measured their time dependence in both stimulated and untimulated pits. Aeq was loaded into pits by membrane permeabilization and resealing at 0°C. The maximum aeq signal (Lmax), obtained by Triton X-100 lysis of pits in the presence of 1 mM Ca, decreased over 40-60 min in a non-linear manner to about 60% of its initial value. Basal [Ca]i also decreased in a similar manner, even after correction for the changes in Lmax. The decreases in both responses were greater in pits isolated in the presence of 1 mM Ca than in the absence of Ca, indicating a sensitivity to external Ca. Epi (1-50 uM) induced an aeq signal in pits of most, but not all, subjects initially, but this response disappeared completely over 40-60 min in most subjects, without a concomitant loss of aggregation response. In contrast, the endoperoxide analog U44069 (10 uM) induced aeq signals in pits from all subjects, which decreased only slightly with time. These results suggest 1) that a portion of pit aeq may be localized in a region of high [Ca]i which may be partially accessible to external Ca, and this may account, in part, for the higher basal [Ca]i reported by aeq than by quin-2; and 2) that the epi-induced aeq signal, which is not prerequisite for aggregation, may be derived primarily from this labile aeq pool since the time courses for the decay of Lmax and basal [Ca]i and the loss of the epi-induced aeq signal are similar.


2017 ◽  
Vol 23 (2) ◽  
Author(s):  
AJAY KUMAR RAJAWAT ◽  
PRAVEEN KUMAR

An attempt has been made to study the Physico-chemical condition of water of Yamuna River at Gokul Barrage, Mathura, (UP). The time period of study was July 2015 to June 2016. Three water samples were selected from different sites in each month for study. The parameters studied were Temperature, Turbidity, pH, DO, BOD, COD, Total Dissolved Solids and Suspended Solids. Almost all the parameters were found above the tolerance limit.


Author(s):  
Marinelle Espino ◽  
Harkaitz Eguiraun ◽  
Oihane Diaz de Cerio ◽  
José Antonio Carrero ◽  
Nestor Etxebarria ◽  
...  

AbstractFeeding 3.9 and 6.7 mg Hg/kg (Se/Hg molar ratios of 0.8 and 0.4, respectively) for 14 days negatively affected Dicentrarchus labrax growth and total DNTB- and thioredoxin-reductase (TrxR) activities and the transcription of four redox genes (txn1, gpx1, txnrd3, and txnrd2) in the liver, but a diet with 0.5 mg Hg/kg (Se/Hg molar ratio 6.6) slightly increased both reductase activities and the transcription of txn1, gpx1, and txnrd2. Feeding 6.7 mg Hg/kg for 53 days downregulated the genes of the thioredoxin system (txn1, txnrd3, and txnrd2) but upregulated gpx1, confirming the previously proposed complementarity among the antioxidant systems. Substitution of 20% of the feed by thawed white fish (hake) slightly counteracted the negative effects of Hg. The effects were not statistically significant and were dependent, in a non-linear manner, on the Se/Hg molar ratio of the feed but not on its Hg concentration. These results stress the need to consider the Se/Hg molar ratio of the feed/food when evaluating the toxicity of Hg.


1989 ◽  
Vol 109 (5) ◽  
pp. 2189-2195 ◽  
Author(s):  
W B Isaacs ◽  
I S Kim ◽  
A Struve ◽  
A B Fulton

Although significant progress has been made regarding the structure and function of titin, little data exist on the biosynthesis of this large protein in developing muscle. Using pulse-labeling with [35S]methionine and immunoprecipitation with an anti-titin mAb, we have examined the biosynthesis of titin in synchronized cultures of skeletal muscle cells derived from day 12 chicken embryos. We find that: (a) titin synthesis increases greater than 4-fold during the first week in culture and during this same time period, synthesis of muscle-specific myosin heavy chain increases greater than 12-fold; (b) newly synthesized titin has a t1/2 of approximately 70 h; (c) titin is resistant to extraction with Triton X-100 both during and immediately after its synthesis. These observations suggest that newly synthesized titin molecules are stable proteins that rapidly associate with the cytoskeleton of developing myotubes.


2010 ◽  
Vol 75 (7) ◽  
pp. 943-950 ◽  
Author(s):  
Svetlana Jeremic ◽  
Slavko Radenkovic ◽  
Ivan Gutman

Cyclic conjugation in benzo-annelated triphenylenes was studied by means of the energy effect (ef) and the ?-electron content (EC) of the six-membered rings. A regularity that was earlier discovered in the case of acenaphthylene and fluoranthene congeners is now shown to hold also for benzo-annelated triphenylenes: Benzenoid rings that are annelated angularly with regard to the central six-membered ring Z0 of triphenylene increase the intensity of the cyclic conjugation in Z0, whereas linearly annelated benzenoid rings decrease the cyclic conjugation in Z0. The efand EC-values are strongly correlated, yet in a non-linear manner.


1986 ◽  
Vol 164 (5) ◽  
pp. 1407-1421 ◽  
Author(s):  
J E Gabay ◽  
J M Heiple ◽  
Z A Cohn ◽  
C F Nathan

We examined the subcellular location of bactericidal factors (BF) in human neutrophils, using an efficient fractionation scheme. Nitrogen bomb cavitates of DIFP-treated PMN were centrifuged through discontinuous Percoll gradients, each fraction extracted with 0.05 M glycine, pH 2.0, and tested for the killing of Escherichia coli. greater than 90% of BF coisolated with the azurophil granules. After lysis of azurophils, 98% of azurophil-derived BF (ADBF) sedimented with the membrane. ADBF activity was solubilized from azurophil membrane with either acid or nonionic detergent (Triton X-100, Triton X-114). Bactericidal activity was linear with respect to protein concentration over the range 0.3-30 micrograms/ml. 0.1-0.3 microgram/ml ADBF killed 10(5) E. coli within 30 min at 37 degrees C. At 1.4 micrograms/ml, 50% of 2 X 10(5) bacteria were killed within 5 min. ADBF was effective between pH 5-8, with peak activity at pH 5.5. Glucose (20 mM), EDTA (1-25 mM), and physiologic concentrations of NaCl or KCl had little or no inhibitory effect on ADBF. ADBF killed both Gram-positive and Gram-negative virulent clinical isolates, including listeria, staphylococci, beta-hemolytic streptococci, and Pseudomonas aeruginosa. Thus, under these conditions of cell disruption, fractionation, extraction, and assay, almost all BF in human PMN appeared to be localized to the membrane of azurophilic granules as a highly potent, broad-spectrum, rapidly acting protein(s) effective in physiologic medium. Some of these properties appear to distinguish ADBF from previously described PMN bactericidal proteins.


The IoT is a new concept that provides a world where smart, connected, embedded systems operate, giving rise to the amount of data from different sources that are considered to have highly useful and valuable information. Data mining would play a critical role in creating smarter IoT. Traditional care of an elderly person is a difficult and complex task. The need to have a caregiver with the elderly person almost all the time drains the human and financial resources of the health care system. The emergence of Artificial intelligence has allowed the conception of technical assistance where it helps and reduces the time spent by the caregiver with the elderly person. This work aims to focus on analyzing techniques that are used for prediction purposes of falls in the elderly. We examine the applicability of three classification algorithms for IoT data. These algorithms are analyzed and a comparative study is undertaken to find the classifier that performs the best analysis on the dataset using a set of predefined performance metrics to compare the results of each classifier.


2021 ◽  
Author(s):  
◽  
Krunoslav Puškar

This thesis deals with the analysis and description of the historical and contemporary anthroponymy of the Kalnik area of the Prigorje region on the basis of both archival and field research carried out throughout a longer period of time. Since there has not been any extensive onomastic reasearch in the very area to date, our goal was to determine the influence of linguistic and extralinguistic changes in the reaserched onomastic categories. The introduction of this thesis provides the geographical, sociohistorical, demographical and linguistic context of the researched area, whereas the subsequent chapters provide a list and analysis of confirmed first names, personal and family nicknames, as well as family names of the reaserched area. First names were researched during nine time periods with a duration of five years, beginning from 1802 and ending in 2014. Because of a wide researched area, we limited our research on the anthroponymic repertoire of the city of Križevci, in which 3020 first names (1579 male and 1441 female names) were confirmed. In the 19th century, during five analysed time periods, 1519 first names were confirmed, out of which 814 male and 705 female names, which were mostly simple based on their structure (91.64%). Concerning the provenance of the first names, we established that almost all names were either Christian names or translated Christian names and that national names occur very rarely and sporadically, only in the second half of the 19th century. By comparison, in the 20th and 21st century, during the last four time periods, 1501 first names have been confirmed, out of which 765 were male and 736 female names. Concerning their structure, they turned out to be mostly compound first names in the 1946- 1950 time period (55.69%), whereas in the 2010-2014 time period they turned out to be predominantly single (97.02%). Concerning their provenance, in the 1946-1950 time period 48.39% of male and 57.58% of female national names were confirmed, whereas in the last time period male national names amount to 4.05%, and female national names to only 1.27%. Personal nicknames are a special anthroponymic category which has not been researched in the Kalnik area. Having limited our field research on 13 places throughout the area, we confirmed 288 real personal nicknames, 245 male and 43 female nicknames, of mostly simple structure (95.14%), which are still mostly used in oral and informal communication. The motivation behind the nicknames has faithfully shown us the extralinguistic reality of the researched area. The most frequent motivational group of nicknames is the one of unknown motivation (23.96%), while the other confirmed groups are nicknames motivated by a first name (12,15%), a physical characteristic of the owner (12.15%), another characteristic of the owner (11,81%), a specific word used by the owner (8.33%), an animal (6.94%), a family name (6.60%), an occupation (6.25%), an ethnonym or toponym (4.51%), a family or social role (2.78%), a professional designation (1.38%), food (1.04%), a name for a plant (1.04%), a subject (0.69%), and another nickname (0.35%). The high frequency of nicknames of unknown motivation shows us the importance of future research of this anthroponymic category because, due to the passage of time, it is difficult to determine the real motivation of every nickname. We came to the same conclusion during our research of family nicknames, another specific anthroponymic category, still quite present in the Kalnik area. Having limited our field research on 12 places throughout the wide researched area, we managed to confirm 173 real family nicknames, whose designated motivational groups provided us with important sociolinguistic pieces of information. Concerning their structure, the majority of family nicknames turned out to be simple (N = 129), whereas concerning their motivation, the majority of family nicknames were of unknown motivation (N = 33). Other motivational groups were the following: a first name (N = 27), an occupation (N = 27), a family name (N = 25), a personal nickname (N = 22), a certain characteristic (N = 13), an ethnonym (N = 10), a toponym (N = 6), a certain subject (N = 6), and an animal (N = 4). All these mentioned different anthroponymic categories (first names, personal and family nicknames) can be confirmed profusely in the last anthroponymic category researched and analysed in this thesis – family names. Having employed the criterion of their minimum continuity of 100 years in the researched area, we have managed to confirm 1360 family names with centuries old continuity, since the 14th century to this very day. With this criterion we also managed to reduce a significant number of over 3000 family names with mostly no continuity, as well as to confirm those last names which had left their trace in the researched area. Of course, not all family names confirmed by this criterion are necessarily connected to the researched area, but are only detected in it. Out of 1360 confirmed family names, we succeeded in determining 189 family names which occur exclusively or mostly in the researched area, 100 family names which do not occur in contemporary anthroponymy of the area, and 97 family names which could also become extinguished in near future. Concerning their structure, the majority of all family names occur without a suffix (N = 681). All the confirmed family names were analysed according to their structure and motivation and listed in our Lexicon of family names at the end of this very thesis.


Development ◽  
1985 ◽  
Vol 89 (1) ◽  
pp. 133-148
Author(s):  
Roger K. W. Smith ◽  
Martin H. Johnson

The effects of aphidicolin, a reversible inhibitor of DNA polymerase alpha, both on replication and on development of the mouse embryo from the 2- and 4-cell stages to the compacted late 8-cell stage have been assessed. The continuous presence of aphidicolin from G1 of the 4-cell stage resulted in inhibition of DNA replication and prevention of division from 4 to 8 cells, but was without effect on the timing or incidence of cell flattening, surface polarization and cytoplasmic polarization. The continuous presence of aphidicolin from G1 of the 2-cell stage resulted in inhibition of DNA replication, division, and polarization. Some slight intercellular flattening in a few embryos did occur. If addition of aphidicolin was delayed by 10 h to early in G2 of the 2-cell stage, further rounds of replication were blocked and some embryos failed to cleave to 4-cells. Nevertheless, almost all embryos showed evidence of flattening and polarization regardless of cell number. In contrast, if aphidicolin was added in G1 of the 2-cell stage and removed after 10 h, the cells showed delayed DNA replication, little evidence of division, and no cell flattening or polarization. We conclude that DNA replication at the 2-cell stage may be essential for the components of compaction studied, but that DNA replication at the 4- and 8-cell stages is not.


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