Calcium mobilization from the avian eggshell during embryonic development

2013 ◽  
Vol 63 (1) ◽  
pp. 33-46 ◽  
Author(s):  
Ola Österström ◽  
Lena Holm ◽  
Clas Lilja

The avian eggshell acts as the major source of calcium for embryogenesis in bird. Using scanning electron microscopy, the inner eggshell surface was analysed before and after embryonic development and its accompanying calcium removal. This was done in eggs from two bird species with different growth rates and modes of development, the precocial Japanese quail Coturnix japonica and the altricial starling Sturnus vulgaris. Next, enzyme histochemistry was used to localize carbonic anhydrase in the extra-embryonic chorioallantoic membrane to provide support for the hypothesis that calcium may be released from the eggshell by means of acidification through the action of carbonic anhydrase. However, neither in the precocial quail nor in the altricial starling could any staining for carbonic anhydrase be detected. These results lead us to the conclusion that the role of carbonic anhydrase in embryonic calcium mobilization from the avian eggshell remains unclear.

2003 ◽  
Vol 94 (3) ◽  
pp. 1204-1212 ◽  
Author(s):  
Barbara E. Taylor ◽  
Michael B. Harris ◽  
E. Lee Coates ◽  
Matthew J. Gdovin ◽  
J. C. Leiter

Central CO2 chemoreception and the role of carbonic anhydrase were assessed in brain stems from Rana catesbeiana tadpoles and frogs. Buccal and lung rhythms were recorded from cranial nerve VII and spinal nerve II during normocapnia and hypercapnia before and after treatment with 25 μM acetazolamide. The lung response to acetazolamide mimicked the hypercapnic response in early-stage and midstage metamorphic tadpoles and frogs. In late-stage tadpoles, acetazolamide actually inhibited hypercapnic responses. Acetazolamide and hypercapnia decreased the buccal frequency but had no effect on the buccal duty cycle. Carbonic anhydrase activity was present in the brain stem in every developmental stage. Thus more frequent lung ventilation and concomitantly less frequent buccal ventilation comprised the hypercapnic response, but the response to acetazolamide was not consistent during metamorphosis. Therefore, acetazolamide is not a useful tool for central CO2 chemoreceptor studies in this species. The reversal of the effect of acetazolamide in late-stage metamorphosis may reflect reorganization of central chemosensory processes during the final transition from aquatic to aerial respiration.


1983 ◽  
Vol 54 (2) ◽  
pp. 483-490 ◽  
Author(s):  
T. Enns ◽  
E. P. Hill

CO2 diffusing capacities (DmCO2) were measured at 22 degrees C on 12 isolated perfused dog lung lobes before and after inhibition of lung tissue carbonic anhydrase (CA) by acetazolamide (Diamox). The hypothesis is that CA in the alveolar-capillary tissue enhances overall transport of CO2 by converting CO2 to HCO-3 within aqueous portions of the tissue. HCO-3 diffuses simultaneously with molecular CO2, increasing the overall CO2 flux, and then converts back to molecular CO2 at the end of the aqueous pathway. To ensure at least partial diffusion limitation, lobes were perfused with phosphate buffer at high pH (7.7) and high flow rates. Plant CA (which is not inhibited significantly by Diamox) was added to the perfusate to provide rapid uptake of CO2 via conversion to HCO-3. After Diamox, DCO2 decreased 39.6%, indicating that CA does increase CO2 transport through lung tissue. Surprisingly, DCO2 exceeds CO diffusing capacity by only 9.3 +/- 2.1 times (without Diamox inhibition) rather than by the factor of 24 predicted by Graham's law on the basis of solubilities and molecular weights of the gases.


2001 ◽  
Vol 280 (1) ◽  
pp. F146-F154 ◽  
Author(s):  
Shuichi Tsuruoka ◽  
Erik R. Swenson ◽  
Snezana Petrovic ◽  
Akio Fujimura ◽  
George J. Schwartz

Membrane-bound carbonic anhydrase (CA) is critical to renal acidification. The role of CA activity on the basolateral membrane of the proximal tubule has not been defined clearly. To investigate this issue in microperfused rabbit proximal straight tubules in vitro, we measured fluid and HCO3 −absorption and cell pH before and after the extracellular CA inhibitor p-fluorobenzyl-aminobenzolamide was applied in the bath to inhibit only basolateral CA. This inhibitor was 1% as permeant as acetazolamide. Neutral dextran (2 g/dl, molecular mass 70,000) was used as a colloid to support fluid absorption because albumin could affect CO2 diffusion and rheogenic HCO3 − efflux. Indeed, dextran in the bath stimulated fluid absorption by 55% over albumin. Basolateral CA inhibition reduced fluid absorption (∼30%) and markedly decreased HCO3 − absorption (∼60%), both reversible when CA was added to the bathing solution. In the presence of luminal CA inhibition, which reduced fluid (∼16%) and HCO3 − (∼66%) absorption, inhibition of basolateral CA further decreased the absorption of fluid (to 74% of baseline) and HCO3 − (to 22% of baseline). CA inhibition also alkalinized cell pH by ∼0.2 units, suggesting the presence of an alkaline disequilibrium pH in the interspace, which would secondarily block HCO3 − exit from the cell and thereby decrease luminal proton secretion (HCO3 −absorption). These data clearly indicate that basolateral CA has an important role in mediating fluid and especially HCO3 −absorption in the proximal straight tubule.


2001 ◽  
Vol 280 (3) ◽  
pp. R870-R878 ◽  
Author(s):  
Stefanie Dragon ◽  
Rosemarie Baumann

In the second half of avian embryonic development cAMP affects major aspects of red blood cell (RBC) function. At day 13/14,progressive developmental hypoxia causes the release of norepinephrine and erythroid β-adrenergic receptor stimulation initiates the coordinate induction of adaptive key events of erythroid differentiation like carbonic anhydrase (CAII) and 2,3-biphosphoglycerate synthesis. Although cAMP-dependent regulation of CAII protein synthesis has been described in detail, no data exist about the transcriptional regulation in embryonic RBC. Here we report that after day 12 of embryonic development, the caII mRNA is accumulating. Hypoxic incubation at day 10 as well as in vitro incubation of isolated RBC with cAMP-elevating agonists strongly induces erythroid caIIexpression. The induction of caII occurs fast and does not require new protein synthesis. By screening several late erythroid genes, we could identify hsp70 as another cAMP-induced gene in definitive RBC. Because caII (but not hsp70) is also induced by cAMP in primitive RBC, the signal may regulate key events of late primitive and definitive erythropoiesis.


Author(s):  
Judith A. Murphy ◽  
Anthony Paparo ◽  
Richard Sparks

Fingernail clams (Muscu1ium transversum) are dominant bottom-dwelling animals in some waters of the midwest U.S. These organisms are key links in food chains leading from nutrients in water and mud to fish and ducks which are utilized by man. In the mid-1950’s, fingernail clams disappeared from a 100-mile section of the Illinois R., a tributary of the Mississippi R. Some factor(s) in the river and/or sediment currently prevent clams from recolonizing areas where they were formerly abundant. Recently, clams developed shell deformities and died without reproducing. The greatest mortality and highest incidence of shell deformities appeared in test chambers containing the highest proportion of river water to well water. The molluscan shell consists of CaCO3, and the tissue concerned in its secretion is the mantle. The source of the carbonate is probably from metabolic CO2 and the maintenance of ionized Ca concentration in the mantle is controlled by carbonic anhydrase. The Ca is stored in extracellular concentric spherical granules(0.6-5.5μm) which represent a large amount of inertCa in the mantle. The purpose of this investigation was to examine the role of raw river water and well water on shell formation in the fingernail clam.


Crisis ◽  
2010 ◽  
Vol 31 (3) ◽  
pp. 160-164 ◽  
Author(s):  
Almir Fajkic ◽  
Orhan Lepara ◽  
Martin Voracek ◽  
Nestor D. Kapusta ◽  
Thomas Niederkrotenthaler ◽  
...  

Background: Evidence on youth suicides from Southeastern Europe is scarce. We are not aware of previous reports from Bosnia and Herzegovina, which experienced war from 1992 to 1995. Durkheim’s theory of suicide predicts decreased suicide rates in wartime and increased rates afterward. Aims: To compare child and adolescent suicides in Bosnia and Herzegovina before and after the war. Methods: Data on youth suicide for prewar (1986–90) and postwar (2002–06) periods were analyzed with respect to prevalence, sex and age differences, and suicide methods. Suicide data from 1991 through 2001 were not available. Results: Overall youth suicide rates were one-third lower in the postwar than in the prewar period. This effect was most pronounced for girls, whose postwar suicide rates almost halved, and for 15–19-year-old boys, whose rates decreased by about a one-fourth. Suicides increased among boys aged 14 or younger. Firearm suicides almost doubled proportionally and were the predominant postwar method, while the most common prewar method had been hanging. Conclusions: The findings from this study indicate the need for public education in Bosnia and Herzegovina on the role of firearm accessibility in youth suicide and for instructions on safe storage in households. Moreover, raising societal awareness about suicide risk factors and suicide prevention is needed.


2018 ◽  
Vol 15 (1) ◽  
pp. 55-72
Author(s):  
Herlin Hamimi ◽  
Abdul Ghafar Ismail ◽  
Muhammad Hasbi Zaenal

Zakat is one of the five pillars of Islam which has a function of faith, social and economic functions. Muslims who can pay zakat are required to give at least 2.5 per cent of their wealth. The problem of poverty prevalent in disadvantaged regions because of the difficulty of access to information and communication led to a gap that is so high in wealth and resources. The instrument of zakat provides a paradigm in the achievement of equitable wealth distribution and healthy circulation. Zakat potentially offers a better life and improves the quality of human being. There is a human quality improvement not only in economic terms but also in spiritual terms such as improving religiousity. This study aims to examine the role of zakat to alleviate humanitarian issues in disadvantaged regions such as Sijunjung, one of zakat beneficiaries and impoverished areas in Indonesia. The researcher attempted a Cibest method to capture the impact of zakat beneficiaries before and after becoming a member of Zakat Community Development (ZCD) Program in material and spiritual value. The overall analysis shows that zakat has a positive impact on disadvantaged regions development and enhance the quality of life of the community. There is an improvement in the average of mustahik household incomes after becoming a member of ZCD Program. Cibest model demonstrates that material, spiritual, and absolute poverty index decreased by 10, 5, and 6 per cent. Meanwhile, the welfare index is increased by 21 per cent. These findings have significant implications for developing the quality of life in disadvantaged regions in Sijunjung. Therefore, zakat is one of the instruments to change the status of disadvantaged areas to be equivalent to other areas.


Author(s):  
Sanjeeva Kumar Goud T ◽  
Rahul Kunkulol

The present study was aimed to study the effect of Sublingual Vitamin D3 on Serum Vitamin D level in Vitamin D deficiency patients. This was a cross-sectional and interventional study. All the Vitamin D deficiency patients of age 18-60years and either gender, willing to participate in the study were included. Patients who had greater than 20 ng/ml were excluded from the study. The total number of participants in our study was 200, out of these 111 males and 89 females, the mean age in our study was 51.07 ± 7.39Yrs. All volunteers were given sublingual vitamin D3 (60,000IU) in six doses every fifteen days of follow up for 3 months. The subject’s serum 25(OH)D levels were estimated before and after the treatment of sublingual vitamin D3. There was a statistically significant difference in serum vitamin D3 level before 16.61±6.71 ng/ml and after 35.80±7.80 ng/ml after treatment with Sublingual Vitamin D3. Six doses of 60,000IU of Vitamin D3 sublingual route having improved the role of serum 25(OH)D levels in the treatment of Vitamin D3 deficiency patients.Keywords: Vitamin D3; Sublingual route


2018 ◽  
Vol 69 (8) ◽  
pp. 2232-2235
Author(s):  
Marius Moga ◽  
Mark Edward Pogarasteanu ◽  
Antoine Edu

The role of arthroscopy in incipient and mild arthrosis, even combined with proximal tibial ostetomy, is well known and well documented. On the other hand, its role in the treatment of advanced arthrosis of the large joints, especially the knee, is a subject of controversy. The proponents of the use of arthroscopy in advanced arthrosis claim that meniscectomy, synovectomy, ostophytectomy, chondral lesion stabilization, arthroscopic release, plica and loose body removal greatly improve the quality of life for most patients, especially if followed by the use of viscoelastic injection, by diminishing pain and improving joint range of motion. The opponents claim that, even though the advantages are clear in the cases that refuse arthroplasty, in all the other cases the surgical indication should be total knee arthroplasty, as the clinical relief is temporary, but with all the risks of a surgical intervention. We have conducted an overview of the recent literature, in order to find objective evidence to sustain either point of view. We focused on articles published that included an objective measurement of before and after clinical status through clinical scores and objective measurements. We also focused on the follow-up period and on the evolution of the pathology after arthroscopy.


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