scholarly journals Cellular transport of lysosomal enzymes: an alternative hypothesis

1977 ◽  
Vol 164 (1) ◽  
pp. 281-282 ◽  
Author(s):  
J B Lloyd
Keyword(s):  
Lysosomal Enzymes ◽  
Alternative Explanation ◽  
Alternative Hypothesis ◽  
Cellular Transport ◽  
Membrane Recycling

Hickman & Neufeld [(1972) Biochem, Biophys. Res. Commun. 49, 992-999] have proposed that lysosomal enzymes reach the lysosomes by means of exocytosis and subsequent pinocytic reincorporation. The results leading to this conclusion are re-assessed and an alternative explanation is advanced that relates to the necessity for membrane recycling in endocytic cells.

scholarly journals An alternative hypothesis of cellular transport of lysosomal enzymes in fibroblasts. Effect of inhibitors of lysosomal enzyme endocytosis on intra- and extra-cellular lysosomal enzyme activities

1978 ◽  
Vol 176 (3) ◽  
pp. 943-950 ◽  
Author(s):  
Kurt Von Figura ◽  
Ernst Weber
Keyword(s):  
Cell Surface ◽  
Lysosomal Enzyme ◽  
Lysosomal Enzymes ◽  
Alternative Hypothesis ◽  
Fold Increase ◽  
Cellular Transport ◽  
Intracellular Enzyme ◽  
Surface Receptors ◽  
Mannose 6 Phosphate ◽  
A Minor

Recapture of lysosomal enzymes secreted by fibroblasts was inhibited by growing the cells in the presence of either free or immobilized antibodies against lysosomal enzymes or in the presence of phosphorylated carbohydrates known to interact with the cell-surface receptors for lysosomal enzymes. The following results were obtained. 1. Conditions that prevent recapture of released lysosomal enzymes increase the rate of extracellular accumulation of these enzymes up to twice that of controls. 2. Growing cells for 12 days in the presence of 0.5mm-mannose 6-phosphate, which decreases β-N-acetylglucosaminidase endocytosis to less than 10% of that of controls, has no effect on the intracellular activity of this and four other lysosomal enzymes. 3. Growing cells for 4 days in the presence of 50mm-mannose 6-phosphate, which is a 1000-fold higher concentration than that required for 50% inhibition of lysosomal enzyme endocytosis, leads to a 4-fold increase in extracellular β-N-acetylglucosaminidase accumulation and a decrease in intracellular enzyme. These results give evidence that, in fibroblasts, transfer of lysosomal enzymes into lysosomes does not require secretion before a receptor-mediated recapture [Hickman & Neufeld (1972) Biochem. Biophys. Res. Commun.49, 992–999]. We propose that (a) lysosomal enzymes are present in a receptor-bound form in those vesicles that fuse with the cell membrane, (b) the major part of the lysosomal enzyme cycles via the cell surface in a receptor-bound form and (c) only a minor part of the lysosomal enzyme is released into the extracellular space during its life cycle.

Common pathways for cellular transport of steroid sulfatase, lysosomal enzymes and the mannose 6-phosphate receptor: An immunocytochemical appraisal

1987 ◽  
Vol 21 (2) ◽  
pp. 205
Author(s):  
Rob Willemsen ◽  
Marian Kroos ◽  
AndréT. Hoogeveen ◽  
JohanM. van Dongen ◽  
ArnoldJ.J. Reuser
Keyword(s):  
Lysosomal Enzymes ◽  
Cellular Transport ◽  
Steroid Sulfatase ◽  
Mannose 6 Phosphate

Tests of an Alternative Explanation of Data Supporting the R Scale of the MMPI as a Measure of Acquiescence

1973 ◽  
Vol 32 (3_suppl) ◽  
pp. 1243-1246 ◽  
Author(s):  
Robert D. Abbott ◽  
R. Michael Fry ◽  
Sylvia Keim-Abbott
Keyword(s):  
Alternative Explanation ◽  
Alternative Hypothesis ◽  
Substantive Content ◽  
Original Hypothesis

An alternative hypothesis explaining the greater proportion of True responses given by Ss with low scores on the R scale of the MMPI when compared with Ss with high scores on the R scale was not supported in two experiments. The results supported the original hypothesis of Edwards and Abbott that the R scale is measuring in some degree the tendency to respond True to personality items and trait adjectives without regard to the substantive content of these items.

Association of pituitary adenoma with neuronal christoma: A TEM study

1994 ◽  
Vol 52 ◽  
pp. 232-233
Author(s):  
Eva Horvath ◽  
Kalman Kovacs ◽  
B. W. Scheithauer ◽  
R. V. Lloyd ◽  
H. S. Smyth
Keyword(s):  
Growth Hormone ◽  
Pituitary Adenoma ◽  
Pituitary Tumor ◽  
Nervous Tissue ◽  
Alternative Explanation ◽  
Growth Hormone Releasing Hormone ◽  
Cell Hyperplasia ◽  
Releasing Hormone ◽  
Secretory Neurons

The association of a pituitary adenoma with nervous tissue consisting of neuron-like cells and neuropil is a rare abnormality. In the majority of cases, the pituitary tumor is a chromophobic adenoma, accompanied by acromegaly. Histology reveals widely variable proportions of endocrine and nervous tissue in alternating or intermingled patterns. The lesion is perceived as a composite one consisting of two histogenetically distinct parts. It has been suggested that the neuronal component, morphologically similar to secretory neurons of the hypothalamus, may initiate adenoma formation by releasing stimulatory substances. Immunoreactivity for growth hormone releasing hormone (GRH) in the neuronal component of some cases supported this view, whereas other findings such as consistent lack of growth hormone (GH) cell hyperplasia in the lesions called for alternative explanation.Fifteen tumors consisting of a pituitary adenoma and a neuronal component have been collected over a 20 yr. period. Acromegaly was present in 11 patients, was equivocal in one, and absent in 3.

Attitude Accessibility as an Alternative Explanation for How Inoculation Confers Resistance

2003 ◽  
Vol 70 (1) ◽  
pp. 1-1 ◽  
Author(s):  
Michael Pfau ◽  
David Roskos-Ewoldsen ◽  
Michelle Wood ◽  
Suya Yin ◽  
Jaeho Cho ◽  
...  
Keyword(s):  
Alternative Explanation ◽  
Attitude Accessibility

Idiographic Dynamics of Positive Affect in GAD

2020 ◽  
Vol 36 (3) ◽  
pp. 500-509
Author(s):  
Hannah G. Bosley ◽  
Devon B. Sandel ◽  
Aaron J. Fisher
Keyword(s):  
Positive Affect ◽  
Structural Equation ◽  
Alternative Hypothesis ◽  
Equation Model ◽  
Aggregated Data ◽  
Regulatory Strategy ◽  
Constant State ◽  
Automatic Search ◽  
Time Lagged ◽  
Exploratory Procedure

Abstract. Generalized anxiety disorder (GAD) is associated with worry and emotion regulation difficulties. The contrast-avoidance model suggests that individuals with GAD use worry to regulate emotion: by worrying, they maintain a constant state of negative affect (NA), avoiding a feared sudden shift into NA. We tested an extension of this model to positive affect (PA). During a week-long ecological momentary assessment (EMA) period, 96 undergraduates with a GAD analog provided four daily measurements of worry, dampening (i.e., PA suppression), and PA. We hypothesized a time-lagged mediation relationship in which higher worry predicts later dampening, and dampening predicts subsequently lower PA. A lag-2 structural equation model was fit to the group-aggregated data and to each individual time-series to test this hypothesis. Although worry and PA were negatively correlated in 87 participants, our model was not supported at the nomothetic level. However, idiographically, our model was well-fit for about a third (38.5%) of participants. We then used automatic search as an idiographic exploratory procedure to detect other time-lagged relationships between these constructs. While 46 individuals exhibited some cross-lagged relationships, no clear pattern emerged across participants. An alternative hypothesis about the speed of the relationship between variables is discussed using contemporaneous correlations of worry, dampening, and PA. Findings suggest heterogeneity in the function of worry as a regulatory strategy, and the importance of temporal scale for detection of time-lagged effects.

Does the Name-Race Implicit Association Test Measure Racial Prejudice?

2011 ◽  
Vol 58 (4) ◽  
pp. 271-277 ◽  
Author(s):  
Don van Ravenzwaaij ◽  
Han L. J. van der Maas ◽  
Eric-Jan Wagenmakers
Keyword(s):  
Diffusion Model ◽  
Implicit Association Test ◽  
Alternative Explanation ◽  
Group Membership ◽  
Racial Prejudice ◽  
Decision Time ◽  
Association Test ◽  
Implicit Association ◽  
Model Decomposition ◽  
Test Measure

Research using the Implicit Association Test (IAT) has shown that names labeled as Caucasian elicit more positive associations than names labeled as non-Caucasian. One interpretation of this result is that the IAT measures latent racial prejudice. An alternative explanation is that the result is due to differences in in-group/out-group membership. In this study, we conducted three different IATs: one with same-race Dutch names versus racially charged Moroccan names; one with same-race Dutch names versus racially neutral Finnish names; and one with Moroccan names versus Finnish names. Results showed equivalent effects for the Dutch-Moroccan and Dutch-Finnish IATs, but no effect for the Finnish-Moroccan IAT. This suggests that the name-race IAT-effect is not due to racial prejudice. A diffusion model decomposition indicated that the IAT-effects were caused by changes in speed of information accumulation, response conservativeness, and non-decision time.

Unconscious recognition in prosopagnosia: An alternative explanation

1991 ◽  
Author(s):  
Martha J . Farah ◽  
Randall C. O'Reilly ◽  
Shaun P. Vecera
Keyword(s):  
Alternative Explanation

An Alternative Explanation for the Shape of 'Log-Spiral' Bays

2007 ◽  
Author(s):  
Ryan Littlewood ◽  
A. Brad Murray ◽  
Andrew D. Ashton
Keyword(s):  
Alternative Explanation

TEACHING READING BY UTILIZING HOT POTATOES SOFTWARE TOWARD STUDENTS’ READING COMPREHENSION OF DESCRIPTIVE TEXT

2018 ◽  
Vol 5 (1) ◽  
pp. 26
Author(s):  
Abdullah Farih
Keyword(s):  
Reading Comprehension ◽  
Alternative Hypothesis ◽  
T Test ◽  
Control Group ◽  
Teaching Reading ◽  
Post Test ◽  
Quasi Experimental ◽  
Independent Variable ◽  
Level Of Significance ◽  
And Control

The objective of this study is to measure whether there is or not significant effect of teaching reading by utilizing Hot Potatoes software toward students’ reading comprehension of descriptive text. The variables used were the teaching treatment of Hot Potatoes Software as the independent variable and the students’ reading comprehension of Descriptive Text as dependent variable. Then, the research designed was Quasi-experimental design and the presentation of data used was quantitative. The data were obtained from the eleventh grade, of which 28 students were taken as sample. The students are divided into two groups; experiment group consisted of 12 students and control group consists of 16 students. To get the data, the pre-test and post-test were applied and then analyzed using t-test formula. The researcher had concluded that there is Significant effect of Hot Potatoes Software toward the students’ reading comprehension achievement. The result showed that mean of students’ post-test was increased. It is proved by the t-test (8.54) which is higher than t-table (2.05) at level of significance 5%. It means that the alternative hypothesis was accepted and it proved that Hot Potatoes Software had significant effect toward students’ reading comprehension of Descriptive Text

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