Thermodynamic and structural study of DMPC–alkanol systems

2021 ◽  
Vol 23 (14) ◽  
pp. 8598-8606
Author(s):  
Mária Klacsová ◽  
Attila Bóta ◽  
Peter Westh ◽  
Sérgio de Souza Funari ◽  
Daniela Uhríková ◽  
...  

A fluid-fluid immiscibility of the DMPC-C12OH system above threshold concentration with a consequent formation of domains with different C12OH contents is suggested.

Author(s):  
Joachim R. Sommer ◽  
Nancy R. Wallace

After Howell (1) had shown that ruthenium red treatment of fixed frog skeletal muscle caused collapse of the intermediate cisternae of the sarcoplasmic reticulum (SR), forming a pentalaminate structure by obi iterating the SR lumen, we demonstrated that the phenomenon involves the entire SR including the nuclear envelope and that it also occurs after treatment with other cations, including calcium (2,3,4).From these observations we have formulated a hypothesis which states that intracellular calcium taken up by the SR at the end of contraction causes the M rete to collapse at a certain threshold concentration as the first step in a subsequent centrifugal zippering of the free SR toward the junctional SR (JSR). This would cause a) bulk transport of SR contents, such as calcium and granular material (4) into the JSR and, b) electrical isolation of the free SR from the JSR.


Author(s):  
James R. Gaylor ◽  
Fredda Schafer ◽  
Robert E. Nordquist

Several theories on the origin of the melanosome exist. These include the Golgi origin theory, in which a tyrosinase-rich protein is "packaged" by the Golgi apparatus, thus forming the early form of the melanosome. A second theory postulates a mitochondrial origin of melanosomes. Its author contends that the melanosome is a modified mitochondria which acquires melanin during its development. A third theory states that a pre-melanosome is formed in the smooth or rough endoplasmic reticulum. Protein aggregation is suggested by one author as a possible source of the melanosome. This fourth theory postulates that the melanosome originates when the protein products of several genetic loci aggregate in the cytoplasm of the melanocyte. It is this protein matrix on which the melanin is deposited. It was with these theories in mind that this project was undertaken.


1997 ◽  
Vol 222 (1-2) ◽  
pp. 131-136
Author(s):  
K Muruganandam
Keyword(s):  

1995 ◽  
Vol 5 (7) ◽  
pp. 763-769 ◽  
Author(s):  
S. Rios ◽  
W. Paulus ◽  
A. Cousson ◽  
M. Quilichini ◽  
G. Heger ◽  
...  

2003 ◽  
Vol 42 (02) ◽  
pp. 71-77 ◽  
Author(s):  
I. Schreivogel ◽  
C. Angerstein ◽  
U. Siefker ◽  
K. Lehmann ◽  
G. Altenvoerde ◽  
...  

SummaryAim: Formal and clinical comparison of a new 3rd-gene-ration-Tg-IRMA (3-G-IRMA; Dynotest®Tg-plus) with a conventional Tg-IRMA (3-G-IRMA; SELco®Tg-assay) for patients with differentiated thyroid carcinoma. In addition we evaluated, if thyroglobulin (Tg) levels above a specific threshold concentration indicate the need for further investigations for residual disease. Patients, methods: Tg concentration of 105 sera of 93 consecutive patients with a differentiated thyroid cancer was determined with both assays and compared at different cut-off values (Dynotest®Tg-plus: 0.2, 1, 2 ng/ml; SELco®Tg-assay: 0.5, 1, 2 ng/ml) with the clinical results in respect to the corresponding TSH concentration. Results: Tg concentration did not show any significant difference (SELco®Tg-assay 0.5 ng/ml, Dynotest® Tg-plus 0.2 ng/ml). The Tg-values of both assays correlated with 97%. However, correlation of recovery in both assays was small (40%). The sensitivities and specificities of both assays at different cut-offs and TSH values did not reveal significant differences. In patients with TSH concentration >30 µU/ml the functional assay sensitivity was superior to arbitrary cut-offs in the decision to start further evaluations. Conclusions: In our study neither formal nor clinical significant differences between two Tg-assays were found. In a hypothyroid patient (TSH >30 µU/ml, Tg concentration exceeding the functional assay sensitivity) further investigations for residual disease are warranted. Higher thresholds are of limited value, due to a inacceptable high rate of false negative results.


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