Assembly of three major subclasses of mouse immunoglobulin G: a theoretical model for covalent assembly in vivo

1976 ◽  
Vol 54 (8) ◽  
pp. 688-698 ◽  
Author(s):  
J. R. Percy ◽  
M. E. Percy ◽  
R. Baumal
Keyword(s):  
Cell Lines ◽  
Immunoglobulin G ◽  
Mean Value ◽  
Individual Values ◽  
In Vitro Assembly ◽  
The Mean ◽  
The Individual ◽  
Mouse Myeloma

A mathematical model, based on second-order reaction kinetics, has been used to describe the covalent assembly of immunoglobulin G (IgG) in vitro from its heavy (H) and light (L) chains (Percy, M. E., Baumal, R., Dorrington, K. J. &Percy, J. (1976) Can. J. Biochem. 54, 675–687). In the present paper, the same model has now been applied to the steady-state assembly of IgG in vivo. This mathematical approach permits a quantitative comparison of the pathways of covalent assembly used by given immunoglobulins in vivo and in vitro. The assumptions in the model are: the species L, H, HL, HH, HHL and LHHL belong to a common pool; incompleted IgG intermediates may freely assemble to form HL, HH, HHL and LHHL; the reaction rate for covalent linkage between any two reacting species is proportional to the products of the number densities of the reactants and to a parameter P which takes the value PHH if the reaction joins two H chains, and PHL if it joins an H and L chain. In vivo values of PHH/PHL were determined for the 18 mouse myeloma tumours and cell lines studied by Baumal et al. (Baumal, R., Potter, M. &Scharff, M. (1971) J. Exp. Med. 134, 1316–1334). From these analyses, we have arrived at the following conclusions: (1) the three major IgG subclasses have distinctive values of PHH/PHL (mean value 53 for IgG1, 12 for IgG2a and 2.8 for IgG2b); (2) for IgGs of the same subclass, the values of PHH/PHL are similar; (3) the mean in vivo values of PHH/PHL are very close to those determined from in vitro assembly experiments. Finally, the individual values of PHH/PHL have been used to simulate pulse-chase experiments in the various tumours and cell lines. Considering the sources and magnitude of experimental error, the theoretical pathways of assembly agree with those determined qualitatively from the pulse-chase experiments.

scholarly journals Modulations of SIR-nucleosome interactions of reconstructed yeast silent pre-heterochromatin by O-acetyl-ADP-ribose and magnesium

2017 ◽  
Vol 28 (3) ◽  
pp. 381-386 ◽  
Author(s):  
Shu-Yun Tung ◽  
Sue-Hong Wang ◽  
Sue-Ping Lee ◽  
Shu-Ping Tsai ◽  
Hsiao-Hsuian Shen ◽  
...  
Keyword(s):  
Gene Silencing ◽  
Chromatin Condensation ◽  
Epigenetic Inheritance ◽  
Assembly System ◽  
Sir Proteins ◽  
Epigenetic Gene Silencing ◽  
In Vitro Assembly ◽  
The Individual

Yeast silent heterochromatin provides an excellent model with which to study epigenetic inheritance. Previously we developed an in vitro assembly system to demonstrate the formation of filament structures with requirements that mirror yeast epigenetic gene silencing in vivo. However, the properties of these filaments were not investigated in detail. Here we show that the assembly system requires Sir2, Sir3, Sir4, nucleosomes, and O-acetyl-ADP-ribose. We also demonstrate that all Sir proteins and nucleosomes are components of these filaments to prove that they are SIR-nucleosome filaments. Furthermore, we show that the individual localization patterns of Sir proteins on the SIR-nucleosome filament reflect those patterns on telomeres in vivo. In addition, we reveal that magnesium exists in the SIR-nucleosome filament, with a role similar to that for chromatin condensation. These results suggest that a small number of proteins and molecules are sufficient to mediate the formation of a minimal yeast silent pre-heterochromatin in vitro.

In Vitro and in Vivo Measurement of Total Antiplasmin Activity

1977 ◽  
Vol 37 (02) ◽  
pp. 216-221 ◽  
Author(s):  
Osamu Matsuo ◽  
Hisashi Mihara
Keyword(s):  
Plasma Volume ◽  
Fibrinolytic Activity ◽  
Mean Value ◽  
Rabbit Plasma ◽  
In Vivo Measurement ◽  
The Mean ◽  
Infusion Speed

SummaryTotal antiplasmin was measured in vitro and in vivo. In the former case, rabbit plasma was mixed with various concentrations of Urokinase (UK) and the least concentration for appearance of fibrinolytic activity was estimated. This concentration was multiplied by the plasma volume of the rabbit to give the in vitro total antiplasmin. The mean value for 14 rabbits was 4,068.6 units.In order to estimate the total antiplasmin in vivo, UK solution was infused into rabbits. The infusion speed was multiplied by the time of the first appearance of fibrinolytic activity to give the total antiplasmin, although when the infusion speed was low, fibrinolytic activity did not appear during infusion. The mean in vivo total antiplasmin calculated for 6 cases where the infusion speed was high and fibrinolytic activity was observed, was 28,699.8 units, i.e. about 7 (range, 3-11) times the in vitro value.

Blood Gases of the Tench (Tinca tinca) in Well Aerated and Oxygen-Deficient Waters

1974 ◽  
Vol 60 (1) ◽  
pp. 71-83 ◽  
Author(s):  
F. B. EDDY
Keyword(s):  
Venous Blood ◽  
Oxygen Affinity ◽  
Blood Gases ◽  
Mean Value ◽  
Hypoxic Conditions ◽  
Arterial Blood ◽  
The Mean ◽  
Tench Tinca Tinca

1. The respiration of tench at 13°C was investigated, particular attention being given to the role of the blood in uptake and transport of oxygen. 2. In well aerated water the mean value for arterial blood was 36 mmHg, for PCOCO2 3.3 mmHg and for pH 8.16; the respective venous values were 7 mmHg, 5 mmHg and 8.08. Arterial blood averaged about 75% and venous blood about 40° oxygen saturation. The mean value for oxygen uptake was 0.5 ml/min/kg and for ventilation volume 132/ml/mm/kg. 3. The oxygen tension and the percentage saturation of the blood determined in vivo are discussed in terms of the oxygen dissociation curve determined in vitro. 4. When the environmental POO2 was decreased, tench responded by increasing breathing rate and ventilation volume. Arterial POO2 and PCOCO2 decreased but arterial pH tended to remain steady. There was also a significant increase in blood lactate. 5. That tenth can withstand severe hypoxic conditions is attributed to blood of high oxygen affinity and the ability to maintain a favourable acid-base status in the blood for oxygen transport. 6. Respiration in tench is compared with that in other fish species.

Effect of morphine on mesangial immunoglobulin G aggregate kinetics

1993 ◽  
Vol 265 (5) ◽  
pp. C1211-C1219 ◽  
Author(s):  
P. C. Singhal ◽  
C. Q. Pan ◽  
N. Gibbons ◽  
E. Valderrama
Keyword(s):  
Immunoglobulin G ◽  
Serum Levels ◽  
Opioid Antagonist ◽  
Focal Glomerulosclerosis ◽  
Mesangial Expansion ◽  
Gold Particles ◽  
Ultrastructural Studies ◽  
The Mean

Because mesangial expansion is considered a precursor of focal glomerulosclerosis, we studied whether morphine can cause mesangial expansion. We used radiolabeled human immunoglobulin G aggregates (125I-ahIgG) to study mesangial kinetics in control and experimental (morphine-treated) rats. Control and experimental rats were administered 125I-ahIgG by tail vein. Serum levels of 125I-ahIgG and uptake of 125I-ahIgG by liver, spleen, and mesangium were determined at 4, 8, 12, 24, and 36 h after 125I-ahIgG administration. Mesangial 125I-ahIgG levels were higher (P < 0.05) at 4 h and at later periods in morphine-treated vs. control rats. Naloxone, an opioid antagonist, did not attenuate the morphine-induced mesangial accumulation of 125I-ahIgG. The mean uptake of IgG aggregates was lower in the liver and spleen of morphine-treated rats at 36 h (P < 0.05). In both in vivo and in vitro experiments, ultrastructural studies showed accumulation of IgG-coated gold particles in vesicles, endosomes, and lysosomes. Morphine may have increased the accumulation of 125I-ahIgG in the glomeruli either by increasing the delivery of macromolecules into the mesangium or by altering the exit of macromolecules from the mesangium.

scholarly journals Variation between sheep in renal excretion of [14C]allantoin

2002 ◽  
Vol 87 (6) ◽  
pp. 561-568 ◽  
Author(s):  
P. Prasitkusol ◽  
E. R. Ørskov ◽  
X. B. Chen ◽  
F. D. DeB. Hovell ◽  
D. J. Kyle
Keyword(s):  
Filtration Rate ◽  
Renal Excretion ◽  
Mean Value ◽  
Purine Derivatives ◽  
Individual Values ◽  
Simple Alternative ◽  
Micro Organisms ◽  
Accuracy Of Prediction

The objectives of the present study were to investigate the recovery of [14C]allantoin in urine of sheep dosed intravenously and degradation of allantoin by rumen micro-organisms. The recovery of [14C]allantoin in the urine of eight sheep was measured during three periods in two experiments. Individual values of [14C]allantoin recovery varied from 66 to 95 % (mean value 83 (SE 1·6) %). The recovery of [14C]allantoin showed no relation to the level of feed intake. There was some evidence that glomerular filtration rate was an important factor affecting the amount of urinary allantoin recovered in one experiment. Incomplete recovery of plasma [14C]allantoin in the urine indicated losses of plasma [14C]allantoin via non-renal routes. This is supported by the disappearance of14C from rumen contents incubatedin vitrowith [14C]allantoin for 48 h (88 %) and the presence of14C in salivain vivofrom sheep sampled after dosing with [14C]allantoin. However, the amount of14C activity in the saliva was very low (equivalent to only 1·5 % of the total dose in sheep producing saliva at a rate of 15 litres/d). The proportion of renal and non-renal excretion of purine derivatives was found to be unpredictable both between and within individual animals. The factors responsible for this variability need to be identified, and existing models of excretion of purine derivatives may need to be modified accordingly to improve their accuracy of prediction. A single intravenous injection of [4,5-14C]allantoin provides a simple alternative to infusion methods used to measure the proportion of plasma allantoin excreted in the urine of sheep. Using this method it may be feasible to validate PD excretion models in other ruminant livestock.

Technozym® ADAMTS-13 ANTIGEN ELISA - A New Assay for Specific Quantification of the vWF Cleaving Protease ADAMTS-13.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 4098-4098
Author(s):  
Helga Vetr ◽  
Sabine Geiter ◽  
Fritz Scheiflinger ◽  
Michael Dockal ◽  
Bernd R. Binder
Keyword(s):  
Sandwich Elisa ◽  
Mean Value ◽  
Individual Values ◽  
Antigen Elisa ◽  
Wide Range ◽  
Antibody Conjugate ◽  
The Mean ◽  
The Individual ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract Defects in activity and/or antigen levels of ADAMTS-13, the von Willebrand Factor (vWF) cleaving protease, are viewed as the main cause inducing the microvascular thrombotic disorder TTP (thrombotic thrombocytopenic purpura) that is in more than 90% of cases fatal if not treated early and appropriately. Malfunction of ADAMTS-13 with respect to cleave multimeric vWF can be caused by auto-antibodies directed against ADAMTS-13, by decreased presence of ADAMTS-13 in the circulation or by defective activity of ADAMTS-13. Therefore rapid and reliable diagnosis of ADAMTS-13 parameters is a clinical need. We present here an assay for quantification of ADAMTS-13 antigen levels. The assay is a regular double sandwich ELISA employing a monoclonal antibody for capturing ADAMTS-13 from the sample by binding to the CUB domains. The bound ADAMTS-13 is detected by a polyclonal antibody conjugate. The sensitivity of the assay is below 10% of the normal antigen level. In normal samples a wide range (50% to 200%) of the mean level was observed. In idiopathic TTP plasmas also a wide range of antigen levels was observed but with a slighltly lower mean value than in normal samples. Samples from hereditary TTP mostly showed lower antigen levels than normal samples. Thus we could show that this assay provides a useful tool for measuring ADAMTS-13 antigen levels. In combination with our activity assay, which is being developed in parallel, it will be possible to establish ratios of activity and antigen which could provide more insight into the mechanisms of ADAMTS-13 deficiencies than the individual values for antigen and activity.

In-Silico Model for Predicting CYP2D6-Mediated Drug-Drug Interactions

2020 ◽  
Vol 15 ◽  
Author(s):  
Roberto Lozano ◽  
Alberto Frutos ◽  
Alejandro Martinez
Keyword(s):  
Drug Interaction ◽  
Therapeutic Range ◽  
Area Under Curve ◽  
Inhibitory Concentration ◽  
Mean Value ◽  
Inhibition Constant ◽  
Constant Ratio ◽  
The Mean

Background: Successful integration of in vitro into in vivo data on drug-drug interaction (DDI) is dependent on the inhibitory concentration used. Obtaining plasma concentration of a drug is only readily available for a small number of drugs in clinical practice, and so we propose the use of a therapeutic range as a substitute for inhibitory concentration. Objective: Because of this, we aimed to construct a linear-regression model based on the area-under-curve of the victim drugs and the therapeutic range, for a set of known inhibitors of the CYP2D6 of interest. Methods: Correlation analysis of linear log-log regression of two main variables: the area-under-curve ratio (AUCr) of the victim drugs and of the therapeutic range-to-inhibition constant ratio, with data obtained from literature. Results: Data were fitted to a linear log-log regression, between the average of the AUCr values and the mean value of the therapeutic range-to-inhibition constant ratio (TRm-to-Ki), of the inhibitory drugs. Conclusions: According to our results, knowledge of the inhibition constant and therapeutic range (or its plasma levels if disponible) of the inhibitor would be sufficient to determine the intensity and clinical relevance of a CYP2D6-mediated DDI.

scholarly journals ENZYME VARIATION, METABOLIC FLUX AND FITNESS: ALCOHOL DEHYDROGENASE IN DROSOPHILA MELANOGASTER

Genetics ◽  
1983 ◽  
Vol 105 (3) ◽  
pp. 633-650
Author(s):  
Richard J Middleton ◽  
Henrik Kacser
Keyword(s):  
Metabolic Flux ◽  
Mean Value ◽  
In Vivo Studies ◽  
Standard Errors ◽  
In Vitro Activity ◽  
Enzyme Variation ◽  
Flux Level ◽  
The Mean

ABSTRACT Although there are many in vitro studies of enzyme activity of genetic variants at the Adh locus in D. melanogaster, little is known about the corresponding metabolic activity in living flies. We report here such measurements of the metabolic flux in the conversion of ethanol to the two products, CO2 and lipids, for six different active genotypes, containing the predominant naturally recurring alleles and covering a threefold range of in vitro activity. In adult flies we have found nonsignificant differences between genotypes in metabolic flux when estimates for individual genotypes had standard errors of approximately 10% of the mean value. In vitro activities are, therefore, poor predictors of the physiological consequences of enzyme variation since such determinations ignore the interactions inherent in multienzyme systems. We have no evidence that heterozygote show overdominance either at the enzyme or the flux level. Since fitness differences between genotypes must be generated by physiological differences, investigations of polymorphisms should be based on in vivo studies.

Oxygen Affinity in Vivo and in Vitro in Chronic Ventilatory Failure

1977 ◽  
Vol 52 (3) ◽  
pp. 277-281
Author(s):  
P. M. Tweeddale ◽  
R. J. E. Leggett ◽  
D. C. Flenley
Keyword(s):  
Healthy Subjects ◽  
Oxygen Affinity ◽  
Significant Difference ◽  
Ventilatory Failure ◽  
The Mean ◽  
The Individual ◽  
Arteriovenous Difference ◽  
Haematological Indices

1. The oxygen affinity in vitro, haematological indices, erythrocyte 2,3-diphosphoglycerate and plasma inorganic phosphate were determined in 20 patients with chronic ventilatory failure and in 20 healthy non-smokers of similar age. 2. No significant difference was observed between the mean oxygen affinity or phosphate concentrations of the patients and healthy subjects but the mean haemoglobin and packed cell volume were significantly higher in the patients. 3. There was a positive correlation between plasma and intraerythrocytic pH which was similar in both patients and healthy subjects. 4. The arteriovenous difference in oxygen saturation in vivo (directly measured at cardiac catheterization) correlated closely with that calculated from the individual patient's oxygen affinity determined in vitro and arterial and mixed venous oxygen and carbon dioxide tensions, suggesting that oxygen affinity in vitro accurately reflects the curve in vivo.

Isolation of cloned Syrian hamster insulinoma cell lines with limited capacity for insulin production

1979 ◽  
Vol 57 (8) ◽  
pp. 819-824 ◽  
Author(s):  
Patricia A. Rae ◽  
Cecil C. Yip ◽  
Bernard P. Schimmer
Keyword(s):  
Cell Lines ◽  
Syrian Hamster ◽  
Mean Value ◽  
Immunoreactive Insulin ◽  
Insulin Production ◽  
Insulinoma Cell ◽  
Doubling Times ◽  
Insulinoma Cell Lines

Cell lines derived from a Syrian hamster insulinoma have been cloned in agar and maintained continuously in culture in vitro for [Formula: see text] years. The cell lines have average doubling times of 48 h, they have modal chromosome numbers between 38 and 39, and they retain the ability to form tumors when injected into Syrian hamsters. The cells do not produce immunoreactive insulin when grown in vitro (<0.5 ng/mg protein), but do produce immunoreactive insulin when grown in vivo as tumors (mean value from six determinations = 7.1 ± 1.5 ng/mg protein).

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