Separation of the submicelles from micellar casein by high performance gel chromatography on a TSK-GEL G4000SW column

1983 ◽  
Vol 50 (1) ◽  
pp. 37-44 ◽  
Author(s):  
Tomotada Ono ◽  
Satoshi Odagiri ◽  
Toshio Takagi
Keyword(s):  
High Performance ◽  
Skim Milk ◽  
Gel Chromatography ◽  
Casein Micelles ◽  
The Third ◽  
Micellar Casein ◽  
Better Than

SummaryBovine caseins from skim-milk (micellar casein and acid precipitated casein) were separated into 4 discrete components by high performance gel chromatography on a TSK-GEL G4000SW columm. The resolution was better than that obtained by conventional gel chromatography which resulted in separation into 2 components at best. Our results showed that the second and third components consisted of αs1- and κ-caseins and αs1- and β-caseins respectively. They are presumed to be submicellar fractions. Samples prepared by removal of Ca phosphate from large and small micelles were rich in the third and the second components respectively. It is suggested that casein micelles consist of αs1- and κ-casein complexes and complexes and polymers of αs1- and β-casein which are situated preferentially on the periphery and in the interior of the micelles respectively.

Dissociation during dialysis of casein aggregates cross-linked by colloidal calcium phosphate in bovine casein micelles

1988 ◽  
Vol 55 (2) ◽  
pp. 189-195 ◽  
Author(s):  
Takayoshi Aoki ◽  
Nagisa Yamada ◽  
Yoshitaka Kako ◽  
Tsuneaki Imamura
Keyword(s):  
High Performance ◽  
Skim Milk ◽  
Dissociation Rate ◽  
Gel Chromatography ◽  
Phosphate Content ◽  
Casein Micelles ◽  
Strength Of Interaction ◽  
Micellar Casein ◽  
Cross Linkage ◽  
The Individual

SummaryCasein micelles separated by ultracentrifugation of raw skim milk were dispersed at a casein concentration of 2·5% in simulated milk ultrafiltrate and dialysed against 10 mM-imidazole buffer (pH 7·0) at 5 °C. The amounts of colloidal Ca and inorganic P decreased from 77 to 11 mg and from 31 to 2 mg respectively in 100 ml during 72 h of dialysis. Micellar casein content was reduced to 43 and 11% after 48 and 72 h of dialysis respectively. In high-performance gel chromatography of casein micelles in the presence of 6 M-urea, fraction 1, consisting of the casein aggregates cross-linked by colloidal Ca phosphate (CCP) decreased during dialysis and the retention time of the peak of fraction 1 was prolonged, suggesting that the cross-linkage between CCP and casein molecules was disrupted. The dissociation rates of the individual casein constituents from the casein aggregates cross-linked by CCP during dialysis were in the order β-> αs1 - > αs2-casein. The higher the ester phosphate content, the slower was the dissociation rate of the individual casein constituent. It is suggested that the strength of interaction between CCP and casein molecules depends on the ester phosphate content.

Stability of buffalo casein micelles

1979 ◽  
Vol 46 (2) ◽  
pp. 401-405 ◽  
Author(s):  
Nripendra C. Ganguli
Keyword(s):  
Sialic Acid ◽  
Gel Filtration ◽  
Skim Milk ◽  
Heat Stability ◽  
Casein Micelles ◽  
Heat Stable ◽  
Micellar Casein ◽  
Acid Release ◽  
The Stability ◽  
Better Than

SUMMARYBuffalo skim-milk is less heat stable than cow skim-milk. Interchanging ultracentrifugal whey (UCW) and milk diffusate with micellar casein caused significant changes in the heat stability of buffalo casein micelles (BCM) and cow casein micelles (CCM). Buffalo UCW dramatically destabilized COM, whereas buffalo diffu-sate with CCM exhibited the highest heat stability.Cow κ-casein stabilizes αs-casein against precipitation by Ca better than buffalo º-casein. About 90% of αs-casein could be stabilized by κ: αs ratios of 0·20 and 0·231 for cow and buffalo, respectively.Sialic acid release from micellar κ-casein by rennet was higher than from acid κ-casein in both buffalo and cow caseins, the release being slower in buffalo. The released macropeptide from buffalo κ-casein was smaller than that from cow κ-casein as revealed by Sephadex gel filtration.Sub-units of BCM have less sialic acid (1·57mg/g) than whole micelles (2·70mg/g). On rennet action, 47% of bound sialic acid was released from sub-units as against 85% from whole micelles. The sub-micelles are less heat stable than whole micelles. Among ions tested, added Ca reduced heat stability more dramatically in whole micelles, whereas added phosphate improved the stability of micelles and, more strikingly, of sub-micelles. Citrate also improved the heat stability of sub-micelles but not of whole micelles.

Separation of casein aggregates cross-linked by colloidal calcium phosphate from bovine casein micelles by high performance gel chromatography in the presence of urea

1986 ◽  
Vol 53 (1) ◽  
pp. 53-59 ◽  
Author(s):  
Takayoshi Aoki ◽  
Yoshitaka Kako ◽  
Tsuneaki Imamura
Keyword(s):  
Calcium Phosphate ◽  
Gel Electrophoresis ◽  
High Performance ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Chromatography ◽  
Casein Micelles ◽  
Milk Serum ◽  
Micellar Casein ◽  
Colloidal Calcium Phosphate ◽  
Phosphate Groups

SUMMARYHigh performance gel chromatography of the casein micelles disaggregated by 6 m-urea was carried out on a TSK-GEL G4000SW column using 6 M-urea synthetic milk serum as the effluent. The eluate was divided into two fractions. Fast eluted fraction 1 decreased from 67·5 to 57·3% on reduction of casein micelles and was not observed in reduced colloidal phosphate-free casein micelles. Fraction 1 from reduced casein micelles contained 1·7 times as much Ca and Pi bound to casein as did whole casein micelles, while fraction 2 essentially contained only bound Ca. These facts indicated that fraction 1 of reduced casein micelles consisted of the casein aggregates cross-linked by colloidal Ca phosphate (CCP). Polyacrylamide-gel electrophoresis showed that fraction 1 of reduced casein micelles contained more αs1- and αs2-caseins and less β-casein than whole micellar casein. No κ-casein was detected in fraction 1 of reduced casein micelles. It is suggested that the ester phosphate groups of casein are the sites for interaction with CCP.

Cleavage of the linkage between colloidal calcium phosphate and casein on heating milk at high temperature

1990 ◽  
Vol 57 (3) ◽  
pp. 349-354 ◽  
Author(s):  
Takayoshi Aoki ◽  
Taketoshi Umeda ◽  
Yoshitaka Kako
Keyword(s):  
High Temperature ◽  
Calcium Phosphate ◽  
Whey Protein ◽  
High Performance ◽  
Gel Chromatography ◽  
Casein Micelles ◽  
Colloidal Calcium Phosphate ◽  
Phosphate Groups

SummaryIn order to examine the effect of heating on the changes in the linkage between colloidal Ca phosphate (CCP) and casein, high-performance gel chromatography of casein micelles disaggregated by 6 M-urea was carried out using 6 M-urea simulated milk ultrafiltrate as the effluent. Although the CCP content increased when whey protein-free (WPF) milk was heated at 60–90 °C for 10 min, almost no changes in the content of casein aggregates cross-linked by CCP were observed. The content of casein aggregates cross-linked by CCP decreased from 51·9 to 46·1% in WPF milk and from 52·3 to 43·6% in concentrated WPF milk on heating at 135–140 °C for 75 s, indicating the cleavage of the linkage between CCP and casein. The cleavage of the linkage between CCP and casein on heating was considered to occur without liberation of ester phosphate groups. It was suggested that the transformation of CCP to another form was responsible for the cleavage between CCP and casein on heating milk at high temperature

Mineral and casein equilibria in milk: effects of added salts and calcium-chelating agents

2000 ◽  
Vol 67 (3) ◽  
pp. 361-370 ◽  
Author(s):  
PUNSANDANI UDABAGE ◽  
IAN R. McKINNON ◽  
MARY-ANN AUGUSTIN
Keyword(s):  
Light Scattering ◽  
Calcium Phosphate ◽  
Chelating Agents ◽  
Skim Milk ◽  
Mineral Salts ◽  
Casein Micelles ◽  
Micellar Size ◽  
Micellar Casein ◽  
Colloidal Calcium Phosphate ◽  
Milk Solids

We have investigated the effects of adding a range of mineral salts and calcium-chelating agents on the distribution of casein and minerals between the non-pelleted and pelleted phases of milk obtained upon centrifugation at 78000 g for 90 min. Adding CaCl2 or mixtures of NaH2PO% and Na2HPO% to reconstituted skim milk (90 g milk solids/kg) at pH 6·65 increased both pelleted casein and pelleted calcium phosphate. Opposite effects were obtained by adding citrate or EDTA. The change in pelleted calcium phosphate was not simply related to casein release from the micelle. Upon adding 5 mmol EDTA/kg milk, 20% of the pelleted Ca, 22% of the pelleted phosphate and 5% of the micellar casein were removed. Increasing the concentration of EDTA to 10 mmol/kg milk decreased the pelleted Ca by 44% and the pelleted phosphate by 46%, and caused 30%of the micellar casein to be released. The effects of adding phosphate, citrate or EDTA at pH 6·65, followed by the addition of CaCl2, demonstrated the reversibility of the dissolution and formation of the micellar calcium phosphate. There were limits to this reversibility that were related to the amount of colloidal calcium phosphate removed from the casein micelles. Adding CaCl2 to milk containing [ges ] 20 mmol EDTA or [ges ] 30 mmol citrate/kg milk did not result in complete reformation of casein micelles. Light-scattering experiments confirmed that the dissolution of moderate amounts of colloidal calcium phosphate had little effect on micellar size and were reversible, while the dissolution of larger amounts of colloidal calcium phosphate resulted in large reductions in micellar size and was irreversible.

Subunit components of casein micelles from bovine, ovine, caprine and equine milks

1989 ◽  
Vol 56 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Tomotada Ono ◽  
Hideaki Kohno ◽  
Satoshi Odagiri ◽  
Toshio Takagi
Keyword(s):  
Molecular Weight ◽  
Light Scattering ◽  
High Performance ◽  
Laser Light ◽  
Laser Light Scattering ◽  
The Other ◽  
Gel Chromatography ◽  
Casein Micelles ◽  
Molecular Weights ◽  
Combined Use

SummarySubunit components of ovine, caprine and equine casein micelles were separated by gel chromatography using a TSK-G4000SW high-performance column and the subunit components of the fractions analysed and compared with bovine casein. Molecular weights of the casein complexes were determined by the combined use of high-performance gel chromatography and low-angle laser light scattering. The caprine and ovine caseins were separated into three peaks (F2, F3 and F4) which were similar to those of bovine casein with respect to composition and molecular weight (500, 100 and 23 K). These F2, F3 and F4 peaks consisted mainly of αs- and κ-casein, αs- and β-casein and β-casein respectively. The equine casein was separated into two components corresponding to F3 and F4 of bovine casein. These F3 and F4 peaks consisted mainly of αs- and β-casein and β-casein respectively. The molecular weight of equine F3 (850 K) was different from that of the other three species. The contents of F2 and F4 in these caseins were dependent on the contents of κ-casein and β-casein respectively.

Advances in imaging SIMS studies of stained and BrdU-labelled human metaphase chromosomes

1995 ◽  
Vol 53 ◽  
pp. 932-933
Author(s):  
R. Levi-Setti ◽  
J. M. Chabala ◽  
R. Espinosa ◽  
M. M. Le Beau
Keyword(s):  
High Performance ◽  
Secondary Ion Mass Spectrometry ◽  
Analytical Sensitivity ◽  
Metaphase Chromosomes ◽  
Banding Patterns ◽  
Sector Mass Spectrometer ◽  
Staining Methods ◽  
The University ◽  
Secondary Ion ◽  
Better Than

We have shown previously that isotope-labelled nucleotides in human metaphase chromosomes can be detected and mapped by imaging secondary ion mass spectrometry (SIMS), using the University of Chicago high resolution scanning ion microprobe (UC SIM). These early studies, conducted with BrdU- and 14C-thymidine-labelled chromosomes via detection of the Br and 28CN- (14C14N-> labelcarrying signals, provided some evidence for the condensation of the label into banding patterns along the chromatids (SIMS bands) reminiscent of the well known Q- and G-bands obtained by conventional staining methods for optical microscopy. The potential of this technique has been greatly enhanced by the recent upgrade of the UC SIM, now coupled to a high performance magnetic sector mass spectrometer in lieu of the previous RF quadrupole mass filter. The high transmission of the new spectrometer improves the SIMS analytical sensitivity of the microprobe better than a hundredfold, overcoming most of the previous imaging limitations resulting from low count statistics.

A Developmental Study of Intonation Recognition

1968 ◽  
Vol 11 (4) ◽  
pp. 825-832 ◽  
Author(s):  
Marilyn M. Corlew
Keyword(s):  
Significant Interaction ◽  
Multiple Choice ◽  
Semantic Content ◽  
First Grade ◽  
Choice Test ◽  
Developmental Study ◽  
Multiple Choice Test ◽  
The Third ◽  
Matching Test ◽  
Better Than

Two experiments investigated the information conveyed by intonation from speaker to listener. A multiple-choice test was devised to test the ability of 48 adults to recognize and label intonation when it was separated from all other meaning. Nine intonation contours whose labels were most agreed upon by adults were each matched with two English sentences (one with appropriate and one with inappropriate intonation and semantic content) to make a matching-test for children. The matching-test was tape-recorded and given to children in the first, third, and fifth grades (32 subjects in each grade). The first-grade children matched the intonations with significantly greater agreement than chance; but they agreed upon significantly fewer sentences than either the third or fifth graders. Some intonation contours were matched with significantly greater frequency than others. The performance of the girls was better than that of the boys on an impatient question and a simple command which indicates that there was a significant interaction between sex and intonation.

Using Connectionist Modules for Decision Support

1990 ◽  
Vol 29 (03) ◽  
pp. 167-181 ◽  
Author(s):  
G. Hripcsak
Keyword(s):  
Decision Support ◽  
Standard Deviation ◽  
Confidence Interval ◽  
Posterior Probability ◽  
Back Propagation ◽  
Connectionist Model ◽  
Test Set ◽  
The Third ◽  
Independent Test ◽  
Better Than

AbstractA connectionist model for decision support was constructed out of several back-propagation modules. Manifestations serve as input to the model; they may be real-valued, and the confidence in their measurement may be specified. The model produces as its output the posterior probability of disease. The model was trained on 1,000 cases taken from a simulated underlying population with three conditionally independent manifestations. The first manifestation had a linear relationship between value and posterior probability of disease, the second had a stepped relationship, and the third was normally distributed. An independent test set of 30,000 cases showed that the model was better able to estimate the posterior probability of disease (the standard deviation of residuals was 0.046, with a 95% confidence interval of 0.046-0.047) than a model constructed using logistic regression (with a standard deviation of residuals of 0.062, with a 95% confidence interval of 0.062-0.063). The model fitted the normal and stepped manifestations better than the linear one. It accommodated intermediate levels of confidence well.

scholarly journals Deep learning for intelligent diagnosis in thyroid scintigraphy

2021 ◽  
Vol 49 (1) ◽  
pp. 030006052098284
Author(s):  
Tingting Qiao ◽  
Simin Liu ◽  
Zhijun Cui ◽  
Xiaqing Yu ◽  
Haidong Cai ◽  
...  
Keyword(s):  
Deep Learning ◽  
Disease Diagnosis ◽  
Kappa Coefficient ◽  
Diagnostic Assessment ◽  
First Year ◽  
Thyroid Scintigraphy ◽  
Diagnostic Ability ◽  
The Third ◽  
Classification Time ◽  
Better Than

Objective To construct deep learning (DL) models to improve the accuracy and efficiency of thyroid disease diagnosis by thyroid scintigraphy. Methods We constructed DL models with AlexNet, VGGNet, and ResNet. The models were trained separately with transfer learning. We measured each model’s performance with six indicators: recall, precision, negative predictive value (NPV), specificity, accuracy, and F1-score. We also compared the diagnostic performances of first- and third-year nuclear medicine (NM) residents with assistance from the best-performing DL-based model. The Kappa coefficient and average classification time of each model were compared with those of two NM residents. Results The recall, precision, NPV, specificity, accuracy, and F1-score of the three models ranged from 73.33% to 97.00%. The Kappa coefficient of all three models was >0.710. All models performed better than the first-year NM resident but not as well as the third-year NM resident in terms of diagnostic ability. However, the ResNet model provided “diagnostic assistance” to the NM residents. The models provided results at speeds 400 to 600 times faster than the NM residents. Conclusion DL-based models perform well in diagnostic assessment by thyroid scintigraphy. These models may serve as tools for NM residents in the diagnosis of Graves’ disease and subacute thyroiditis.

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