scholarly journals Histochemical localization of enzymes and lipids in the ovary of a vespertilionid bat, Scotophilus heathi, during the reproductive cycle

2005 ◽  
Vol 65 (1) ◽  
pp. 179-186 ◽  
Author(s):  
U. P Singh ◽  
A Krishna ◽  
T. D. Smith ◽  
K. P. Bhatnagar
Keyword(s):  
Enzyme Activity ◽  
Seasonal Changes ◽  
Hydroxysteroid Dehydrogenase ◽  
Interstitial Cells ◽  
The Other ◽  
Breeding Period ◽  
Winter Dormancy ◽  
Total Lipids ◽  
High Incidence ◽  
Reproductive Phases

The present study describes seasonal changes in delta5 3beta hydroxysteroid dehydrogenase (3beta-HSD), glusose-6 phosphates dehydrogenase (G-6-PD), and lipids in the ovary of a vespertilionid bat, Scotophilus heathi. Total lipids and 3beta-HSD activity are restricted to thecal and interstitial cells of the ovary. The total lipids, 3beta-HSD, and G-6-PD significantly increase during recrudescence, and remain high during winter dormancy and breeding as compared to the other reproductive phases. High incidence of lipids and enzyme activity in interstitial cells during the breeding period and at the time of ovulation clearly suggests that these cells are actively involved in steroidogenesis. A decline in enzymes and lipid activity during winter dormancy, which correlates with the declining levels of steroidogenesis, might be the factors responsible for prolonged survival of the Graafian follicle in the ovary of S. heathi.

THE HISTOCHEMICAL PATTERN OF THE HUMAN ADULT TESTES

1967 ◽  
Vol 55 (3) ◽  
pp. 415-426 ◽  
Author(s):  
Joh. Koudstaal ◽  
E. L. Frensdorf ◽  
J Kremer ◽  
J. M. Mudde ◽  
M. J. Hardonk
Keyword(s):  
Enzyme Activity ◽  
Alcohol Dehydrogenase ◽  
Sertoli Cells ◽  
Leydig Cells ◽  
Secondary Alcohol ◽  
Hydroxysteroid Dehydrogenase ◽  
Interstitial Cells ◽  
Human Adult ◽  
Secondary Alcohol Dehydrogenase

ABSTRACT The histochemical pattern of the human testes has been investigated. Steroid-producing Leydig cells are characterized by the enzymes 3β ol-hydroxysteroid dehydrogenase and secondary alcohol dehydrogenase. The presence of the last mentioned enzyme precedes that of the 3β ol-hydroxysteroid dehydrogenase. Fibroblast-like interstitial cells showed only enzyme activity of the secondary alcohol dehydrogenase. The best results for indicating the presence of the enzyme 3β ol-hydroxysteroid dehydrogenase were obtained by the method of Allen (1960) with the substrate androst-4-ene-3β,17β-diol. No activity of 3β ol-hydroxysteroid dehydrogenase and the secondary alcohol dehydrogenase was found in the Sertoli cells.

THE INFLUENCE OF HAEMOGLOBIN-S AND G6PD DEFICIENCY ON THE ACTIVITY OF THE 17β-HYDROXYSTEROID DEHYDROGENASE OF INTACT HUMAN ERYTHROCYTES

1974 ◽  
Vol 75 (4) ◽  
pp. 793-800
Author(s):  
A. O. Sogbesan ◽  
O. A. Dada ◽  
B. Kwaku Adadevoh
Keyword(s):  
Enzyme Activity ◽  
Dehydrogenase Activity ◽  
Sex Steroids ◽  
G6pd Deficiency ◽  
Incubation Medium ◽  
Hydroxysteroid Dehydrogenase ◽  
G6pd Activity ◽  
Reverse Transformation ◽  
Oxidative Transformation ◽  
Haemoglobin S

ABSTRACT The 17β-hydroxysteroid dehydrogenase activity in intact erythrocytes of Nigerian patients, in particular with regard to haemoglobin genotypes and G6PD* activity was studied. The G6PD activity of the erythrocyte did not affect the oxidative transformation of testosterone to androstenedione and of oestradiol to oestrone. The reduction (reverse transformation) was inhibited in G6PD-deficient erythrocytes but this inhibition was offset by the addition of 0.025 m glucose to the incubation medium. The per cent oxidation transformation of testosterone was higher in Hb-AA than in Hb-SS erythrocytes. It is suggested that the differences may be a result of either lower enzyme activity in the Hb-SS erythrocytes or of differences in the uptake and possibly binding of sex steroids by intact Hb-SS and Hb-AA erythrocytes.

Relative Distribution and Incidence of Viruses Associated with Disease Outbreaks in Tomato Fields in Trinidad

2006 ◽  
Vol 7 (1) ◽  
pp. 29
Author(s):  
S. N. Rampersad
Keyword(s):  
Production Systems ◽  
Management Strategies ◽  
Disease Outbreaks ◽  
Tobacco Etch Virus ◽  
The Other ◽  
Multiple Infections ◽  
Relative Distribution ◽  
Tomato Production ◽  
Viral Pathogen ◽  
High Incidence

Tomato production in Trinidad has suffered considerable losses in yield and fruit quality due to infections of hitherto surmised etiology. In order to develop strategies for controlling viral diseases in tomato, the relative distribution and incidence of seven viruses that commonly infect tomato were determined. Of the 362 samples tested, Potato yellow mosaic Trinidad virus (PYMTV) was found in every farm except two and was present at relatively high incidence throughout the country. Tobacco mosaic virus (TMV) and Tobacco etch virus (TEV) were found in fewer farms and at lower incidences while the other viruses were absent. Single infections of either virus were more common than double infections and multiple infections were rare but present. The results indicated that PYMTV is the predominant and most important viral pathogen in tomato production systems in Trinidad; however, begomovirus disease management strategies will also have to accommodate controls Accepted for publication 10 January 2006. Published 9 March 2006.

scholarly journals Interaction of soluble glucosyl- and mannosyl-transferase enzyme activities in the synthesis of a glucomannan

1972 ◽  
Vol 129 (3) ◽  
pp. 645-655 ◽  
Author(s):  
J. S. Heller ◽  
C. L. Villemez
Keyword(s):  
Enzyme Activity ◽  
Enzyme Activities ◽  
Enzyme Preparation ◽  
The Other ◽  
Acceptor Molecule ◽  
Soluble Enzyme ◽  
Phaseolus Aureus ◽  
Polymeric Product ◽  
Sugar Nucleotide ◽  
Solubilized Enzyme

A neutral-detergent-solubilized-enzyme preparation derived from Phaseolus aureus hypocotyls contains two types of glycosyltransferase activity. One, mannosyltransferase enzyme activity, utilizes GDP-α-d-mannose as the sugar nucleotide substrate. The other, glucosyltransferase enzyme activity, utilizes GDP-α-d-glucose as the sugar nucleotide substrate. The soluble enzyme preparation catalyses the formation of what appears to be a homopolysaccharide when either sugar nucleotide is the only substrate present. A β-(1→4)-linked mannan is the only polymeric product when only GDP-α-d-mannose is added. A β-(1→4)-linked glucan is the only polymeric product when only GDP-α-d-glucose is added. In the presence of both sugar nucleotides, however, a β-(1→4)-linked glucomannan is formed. There are indications that endogenous sugar donors may be present in the enzyme preparation. There appear to be only two glycosyltransferases in the enzyme preparation, each catalysing the transfer of a different sugar to the same type of acceptor molecule. The glucosyltransferase requires the continual production of mannose-containing acceptor molecules for maintenance of enzyme activity, and is thereby dependent upon the activity of the mannosyltransferase. The mannosyltransferase, on the other hand, does not require the continual production of glucose-containing acceptors for maintenance of enzyme activity, but is severely inhibited by GDP-α-P-glucose. These properties promote the synthesis of β-(1→4)-linked glucomannan rather than β-(1→4)-linked glucan plus β-(1→4)-linked mannan when both sugar nucleotide substrates are present.

How “Native” Are Heritage Speakers?

2013 ◽  
Vol 10 (2) ◽  
pp. 153-177 ◽  
Author(s):  
Silvina Montrul
Keyword(s):  
Language Learning ◽  
Experimental Evidence ◽  
Native Speakers ◽  
Learning Experience ◽  
Age Of Acquisition ◽  
The Other ◽  
Gender Agreement ◽  
Heritage Speakers ◽  
High Incidence ◽  
Incomplete Acquisition

One of the chief characteristics of heritage speakers is that they range in proficiency from “overhearers” to “native” speakers. To date, the vast majority of linguistic and psycholinguistic studies have characterized the non-target-like linguistic abilities of heritage speakers as a product of incomplete acquisition and/or attrition due to reduced exposure and opportunities to use the language during childhood. This article focuses on the other side of the problem, emphasizing instead the high incidence of native-like abilities in adult heritage speakers. I illustrate this issue with recent experimental evidence from gender agreement in Spanish, a grammatical feature that is mastered at almost 100% accuracy in production by native speakers;yet it is one of the most difficult areas to master for non-native speakers, including near-natives.I discuss how age of acquisition and language-learning experience explain these effects.

Pharmacogenetics: Its Place in Medicine and Biology

1992 ◽  
Vol 5 (6) ◽  
pp. 312-316 ◽  
Author(s):  
Werner Kalow
Keyword(s):  
Infectious Disease ◽  
Drug Toxicity ◽  
Rare Variants ◽  
The Other ◽  
New Drugs ◽  
Case Histories ◽  
High Incidence ◽  
New Knowledge ◽  
Toxic Exposures ◽  
Technical Advances

A young science serves its purpose if it leads not only to new knowledge, but to new insights and concepts. This article opens with examples to illustrate some former thinking that the introduction of pharmacogenetic has overcome. Pharmacogenetic case histories from discovery to the present illustrate the interlocking of observations, technical advances, and changing concepts. There are striking biological similarities between pharmacogenetics and those inborn factors that cause resistance to infectious disease: Both represent person-to-person variations that may help the survival of populations, one when facing massive toxic exposures, the other when facing plagues and epidemics. Thus pharmacogenetics represents a biologically necessary variability of the defenses against chemical intruders, and this includes drugs. While this variability is desirable, drug toxicity occurring on the basis of this variability must be avoided. The most successful defendants against toxicity due to polymorphic (ie, high incidence) variants should be the designers of new drugs. The only defender concerned with rare variants can be the attentive clinician.

An in vitro microdialysis methodology to study 11β-hydroxysteroid dehydrogenase type 1 enzyme activity in liver microsomes

2007 ◽  
Vol 370 (1) ◽  
pp. 26-37 ◽  
Author(s):  
Li Sun ◽  
Julie A. Stenken ◽  
Amy Y. Yang ◽  
Jamie J. Zhao ◽  
Donald G. Musson
Keyword(s):  
Enzyme Activity ◽  
Liver Microsomes ◽  
Hydroxysteroid Dehydrogenase

scholarly journals Isolation and characterization of bleomycin-resistant clones of CHO cells

1979 ◽  
Vol 34 (3) ◽  
pp. 269-279 ◽  
Author(s):  
Sylvia Brabbs ◽  
J. R. Warr
Keyword(s):  
Enzyme Activity ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Tween 80 ◽  
The Other ◽  
Resistant Clone ◽  
Ovary Cells ◽  
Isolation And Characterization ◽  
Significant Difference

SUMMARYFive clones of Chinese hamster ovary cells with increased resistance to bleomycin have been isolated following ethylmethanesulphonate mutagenesis. Resistance was stable in three of the clones, but unstable in the other two. One of the stably resistant clones was cross resistant to unrelated drugs, and in contrast to the parental cells, its response to bleomycin was potentiated by tween 80. These two observations suggested a membrane alteration in the resistant clone. There was no significant difference in bleomycin-inactivating enzyme activity between the parental and resistant clones.

scholarly journals VENOUS CONDUITS IN CORONARY SURGERY: OLD PROBLEMS — NEW SOLUTIONS

2019 ◽  
Vol 34 (1) ◽  
pp. 24-32
Author(s):  
Y. Y. Vecherskiy ◽  
D. V. Manvelyan ◽  
V. V. Zatolokin ◽  
V. M. Shipulin
Keyword(s):  
Coronary Artery ◽  
Soft Tissues ◽  
The Other ◽  
Wound Complications ◽  
Coronary Surgery ◽  
Surgical Revascularization ◽  
Other Hand ◽  
Venous Shunt ◽  
High Incidence

The introduction of autovenous coronary artery bypass grafting (CABG) marked the era of surgical revascularization in patients with coronary artery disease. It provided effective treatment for angina and significantly improved the long-term prognosis. Venous transplants today remain the most popular conduits in coronary surgery due to their availability, ease of harvesting, and the absence of length restrictions. Despite the advantages of autovenous CABG, the main disadvantage is the high incidence of venous graft failure, which represents an important and unresolved problem in cardiac and cardiovascular surgery. On the other hand, the traditional allocation of a large saphenous vein implies the dissection of soft tissues throughout the length of the isolated conduit. Traumatic dissection causes a long-lasting persistent pain syndrome after surgery, frequent abnormalities in  skin sensitivity, and a high incidence of wound complications in the lower extremities. These complications lengthen the period of rehabilitation of patients and worsen the quality of life. There is an approach of isolating the vein in a block with surrounding tissues to optimize the long-term functioning of the venous shunt, however, this technique is even more traumatic than the traditional method, and therefore its use is limited in practice. On the other hand, the introduction of minimally invasive methods of isolation allowed to reduce the incidence of wound complications and to improve the cosmetic result, but there is no convincing data regarding the effect on the consistency of shunts in the long-term postoperative period. The problems associated with the use of venous conduits in CABG are multifaceted, and their solutions are necessary to improve the effectiveness of surgical revascularization.

scholarly journals EFFECT OF USING L-ASPARAGINASE IN REDUCING ACRYLAMIDE PERCENTAGE IN BISICUT

2016 ◽  
Vol 47 (4) ◽  
Author(s):  
Jebur & et al.
Keyword(s):  
High Performance Liquid Chromatography ◽  
Enzyme Activity ◽  
Liquid Chromatography ◽  
High Performance ◽  
Specific Activity ◽  
Control Sample ◽  
The Other ◽  
Enzyme Efficiency ◽  
Negative Effect ◽  
The Stability

This study was aimed to know the efficiency of partially purified L- asparaginase produced from local isolate from Erwinia spp. to reduce the percentage of acrylamide formed in Biscuit. Four types of biscuit from wheat flour were prepared (T1, T2, T3, T4),and T1 as control. High performance liquid chromatography technique was used to estimate acrylamide ratio in biscuit , Effect of enzyme addition  on flour chemical and rheological properties was studied, also dough behavior ,gluten percentage, water absorption and amylase enzyme activity was estimated. The results revealed  that  the  addition of  experimental asparaginase ( specific activity 20.5 unite mg-1 ) with 1% of flour weight lead to reduce in acrylamide formation in Biscuit  to 89 %  compared  to  control sample ( in absence of enzyme ) . Moreover, the addition of Asparagine to flour at 0.1 % of its weight, where L- asparaginase was available caused a negative effect on enzyme efficiency in reducing the acrylamide in biscuit. So the level of acrylamide was reduced to 57.7 %. In the other hand , the percentage of acryl amide in biscuit was increased to   233 % when the asparagine was added to mixture in absence of L- asparaginase .Addition of  the enzyme to flour have no effect on the percentage value of gluten but improved the  stability of dough .The  enzyme  addition also led to increase amylases activities.  Addition of experimental enzyme had no effect on quality and sensory evaluation of biscuit.

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