scholarly journals The stability of immunoglobulin a in human milk and saliva stored on filter paper at ambient temperature

2011 ◽  
Vol 23 (6) ◽  
pp. 823-825 ◽  
Author(s):  
Elizabeth M. Miller ◽  
Daniel S. Mcconnell
Keyword(s):  
Human Milk ◽  
Ambient Temperature ◽  
Filter Paper ◽  
Immunoglobulin A ◽  
The Stability

Cholesterol in Serum and Lipoprotein Fractions

1956 ◽  
Vol 2 (3) ◽  
pp. 145-159 ◽  
Author(s):  
Joseph T Anderson ◽  
Ancel Keys
Keyword(s):  
Human Serum ◽  
Total Cholesterol ◽  
Filter Paper ◽  
Room Temperature ◽  
Paper Electrophoresis ◽  
Cholesterol Content ◽  
Intraindividual Variability ◽  
Detailed Data ◽  
The Stability ◽  
Source Of Error

Abstract 1. Methods are described for the separation, by paper electrophoresis and by cold ethanol, of α- and β-lipoproteins in 0.1 ml. of serum, with subsequent analysis of cholesterol in the separated portions. 2. It is shown that both methods of separation yield separated fractions containing substantially the same amounts of cholesterol. 3. Detailed data are given on the errors of measurement for total cholesterol and for cholesterol in the separated lipoprotein fractions. 4. Studies are reported on the stability of cholesterol in stored serum and on paper electrophoresis strips. It is shown that simple drying on filter paper causes no change in cholesterol content and yields a product that is stable for many weeks at ordinary room temperature. 5. The sources of variability in human serum cholesterol values are examined and it is shown that spontaneous intraindividual variability is a much greater source of error than the errors of measurement with these methods.

scholarly journals Human Milk Antibodies Against SARS-CoV-2: A Longitudinal Follow-Up Study

2021 ◽  
pp. 089033442110301
Author(s):  
Hannah G. Juncker ◽  
M. Romijn ◽  
Veerle N. Loth ◽  
Tom G. Caniels ◽  
Christianne J.M. de Groot ◽  
...  
Keyword(s):  
Human Milk ◽  
Clinical Symptoms ◽  
Immunoglobulin A ◽  
Spike Protein ◽  
Enzyme Linked Immunosorbent Assay ◽  
Follow Up Study ◽  
Lactating Mothers ◽  
Milk Antibodies ◽  
Over Time

Background: Human milk contains antibodies against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) following Coronavirus Disease 2019 (COVID-19). These antibodies may serve as protection against COVID-19 in infants. However, the evolution of these human milk antibodies over time is unclear. Research Aim: To elucidate the evolution of immunoglobulin A (IgA) against SARS-CoV-2 in human milk after a SARS-CoV-2 infection. Methods: This longitudinal follow-up study included lactating mothers ( N = 24) who had participated in the COVID MILK study. To assess the evolution of SARS-CoV-2 antibodies, serum and human milk samples were collected 14–143 days after the onset of clinical symptoms related to COVID-19. Enzyme-Linked ImmunoSorbent Assay was used to detect antibodies against the ectodomain of the SARS-CoV-2 spike protein. Results: SARS-CoV-2 antibodies remain present up to 5 months (143 days) in human milk after onset of COVID-19 symptoms. Overall, SARS-CoV-2 IgA in human milk seems to gradually decrease over time. Conclusion: Human milk from SARS-CoV-2 convalescent lactating mothers contains specific IgA antibodies against SARS-CoV-2 spike protein up to at least 5 months post-infection. Passive viral immunity can be transferred via human milk and may serve as protection for infants against COVID-19. Dutch Trial Register on May 1st, 2020, number: NL 8575, URL: https://www.trialregister.nl/trial/8575 .

scholarly journals Insufficient Stability of Clavulanic Acid in Widely Used Child-Appropriate Formulations

Antibiotics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 225
Author(s):  
Ines Mack ◽  
Mike Sharland ◽  
Janneke M. Brussee ◽  
Sophia Rehm ◽  
Katharina Rentsch ◽  
...  
Keyword(s):  
Ambient Temperature ◽  
Clavulanic Acid ◽  
Storage Conditions ◽  
Essential Medicines ◽  
Active Components ◽  
Middle Income ◽  
Ambient Temperatures ◽  
Essential Medicines List ◽  
Dispersible Tablets ◽  
The Stability

Amoxicillin-clavulanic acid (AMC) belongs to the WHO Essential Medicines List for children, but for optimal antimicrobial effectiveness, reconstituted dry powder suspensions need to be stored in a refrigerated environment. Many patients in low- and middle-income countries who are sold AMC suspensions would be expected not to keep to the specified storage conditions. We aimed to assess the stability of both ingredients in liquid formulations and dispersible tablets, combined with nationally representative data on access to appropriate storage. Degradation of amoxicillin (AMX) and clavulanic-acid (CLA) was measured in suspensions and dispersible tablets commercially available in Switzerland at different ambient temperatures (8 °C vs. 28 °C over 7 days, and 23 °C vs. 28 °C over 24 h, respectively). Data on access to refrigeration and electricity were assessed from the USAID-funded Demographic and Health Survey program. In suspensions, CLA degraded to a maximum of 12.9% (95% CI −55.7%, +29.9%) at 8°C and 72.3% (95% CI −82.8%, −61.8%) at a 28 °C ambient temperature during an observation period of 7 days. Dispersible tablets were observed during 24 h and CLA degraded to 15.4% (95% CI −51.9%, +21.2%) at 23 °C and 21.7% (−28.2%, −15.1%) at a 28 °C ambient temperature. There is relevant degradation of CLA in suspensions during a 7-day course. To overcome the stability challenges for all active components, durable child-appropriate formulations are needed. Until then, prescribers of AMC suspensions or pharmacists who sell the drug need to create awareness for the importance of proper storage conditions regarding effectiveness of both antibiotics and this recommendation should be reflected in the WHO Essential Medicines List for children.

scholarly journals Six catalytic activities and cytotoxicity of immunoglobulin G and secretory immunoglobulin A from human milk

2021 ◽  
Author(s):  
Georgy A. Nevinsky ◽  
Ol'ga D. Zakharova ◽  
Ivan Yu. Kompaneets ◽  
Anna M. Timofeeva ◽  
Pavel S. Dmitrenok ◽  
...  
Keyword(s):  
Human Milk ◽  
Immunoglobulin G ◽  
Immunoglobulin A ◽  
Secretory Immunoglobulin A ◽  
Catalytic Activities ◽  
Secretory Immunoglobulin

The Impact of Storage Conditions on the Stability of Lactobacillus rhamnosus GG and Bifidobacterium animalis subsp. lactis Bb12 in Human Milk

2017 ◽  
Vol 12 (9) ◽  
pp. 566-569 ◽  
Author(s):  
Anastasia Mantziari ◽  
Juhani Aakko ◽  
Himanshu Kumar ◽  
Satu Tölkkö ◽  
Elloise du Toit ◽  
...  
Keyword(s):  
Human Milk ◽  
Lactobacillus Rhamnosus ◽  
Storage Conditions ◽  
Lactobacillus Rhamnosus Gg ◽  
Bifidobacterium Animalis ◽  
The Stability ◽  
The Impact

Fluorometric micromethod for determination of arginase activity in dried blood spots on filter paper.

1980 ◽  
Vol 26 (8) ◽  
pp. 1198-1200 ◽  
Author(s):  
A P Orfanos ◽  
E W Naylor ◽  
R Guthrie
Keyword(s):  
Filter Paper ◽  
Colorimetric Method ◽  
Dried Blood Spots ◽  
Arginase Activity ◽  
Kinetic Reaction ◽  
Hematological Disorders ◽  
Blood Spots ◽  
Blood Specimens ◽  
The Stability

Abstract We describe a microfluorometric method for determination of arginase activity in dried blood spots on filter paper. The arginase in discs punched from such dried blood specimens is activated by preincubation with Mn2+ at 37 degrees C. After incubation with substrate at the same temperature, urea is determined fluorometrically by oxidation of NADH to NAD+ in a coupled kinetic reaction. We compare the results of this method with those of a colorimetric method involving liquid blood samples, and assess the stability of the enzyme in dried blood on filter paper. The presence of serum has no effect on the activity. This method may be useful in the early detection of arginase deficiency and certain hematological disorders.

scholarly journals Creep Instability of Ice Sheets

1976 ◽  
Vol 16 (74) ◽  
pp. 278-279
Author(s):  
Garry K.C. Clarke
Keyword(s):  
Melting Point ◽  
Ambient Temperature ◽  
Finite Thickness ◽  
Wave Number ◽  
Slab Thickness ◽  
Perturbation Equation ◽  
Rate Of Increase ◽  
The Stability ◽  
Image Position ◽  
Advection Velocity

Abstract The equation governing the growth or decay of a temperature perturbation T’ in an ice slab under shear stress σ xy is where K and k are respectively the thermal conductivity and diffusivity of ice, KB-v is the advection velocity normal to the bed and is the rate of increase of strain heating with temperature assuming a power law for flow. For a slab of infinite thickness under constant stress and at constant ambient temperature, T Fourier analysis gives -k2+a/k < o as the condition for stability where k is the wave number of a sinusoidal perturbation. When the slab has finite thickness the stability depends on the sign of the eigenvalues λm of the perturbation equation and on the boundary condition at the ice-rock interface. In general the eigenfunctions and eigenvalues must be found by approximate methods such as the Rayleigh-Ritz procedure but in the case where the stress and ambient temperature are constant over the slab thickness and there is no advection the eigenfunctions are either sines or cosines depending on the boundary conditions. In this special case the stability condition is if the bed is frozen and if it is at the melting point. The eigenvalue associated with the smallest value of m is the least stable so the maximum stable thickness is thus h = ½ π(a/K)1/2 if the bed is frozen or h = π (a/K)1/2 if it is at the melting point. For typical flow-law parameters these depths are around 250 m and 500 m respectively. The eigenvalues are related in a simple way to the growth or decay rates of the eigenfunctions: (K λm)–1 is the time constant for the mth eigenfunction. Depth-dependent stress, temperature, and advection have a marked effect on stability. A slab in which stress and temperature increase to values B and T B at the bed is considerably more stable than a slab held at constant stressσB and a constant temperature T B. Advection normal to the bed also has a major influence on stability. If the advection velocity is taken to vary linearly with depth and the bed is frozen, the effect of upward advection is to decrease stability and of downward advection to increase it. When the bed is temperate the effect of advection is more complex: downward advection increases stability but upward advection may increase or decrease it depending on the magnitude of the advection velocity.

Determination of Interleukin 6 (IL-6) and Secretory Immunoglobulin A (Ig As) in Human Milk (Colostrum)

2006 ◽  
Vol 117 (2) ◽  
pp. S209 ◽  
Author(s):  
D.C. Rodríguez ◽  
D.M. Larrauri ◽  
J.L. Liporaci ◽  
E. Martinez ◽  
L.J. Feo ◽  
...  
Keyword(s):  
Human Milk ◽  
Interleukin 6 ◽  
Immunoglobulin A ◽  
Secretory Immunoglobulin A ◽  
Secretory Immunoglobulin

scholarly journals The Stability of Icosahedral Cd-Yb

2003 ◽  
Vol 805 ◽  
Author(s):  
Günter Krauss ◽  
Sofia Deloudi ◽  
Andrea Steiner ◽  
Walter Steurer ◽  
Amy R. Ross ◽  
...  
Keyword(s):  
Low Temperature ◽  
Ambient Temperature ◽  
Mechanical Stress ◽  
Single Crystals ◽  
High Temperatures ◽  
Low Temperatures ◽  
Ambient Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Stability

ABSTRACTThe stability of single-crystalline icosahedral Cd-Yb was investigated using X-ray diffraction methods in the temperature range 20 K ≤ T ≤ 900 K at ambient pressure and from ambient temperature to 873 K at about 9 GPa. Single-crystals remain stable at low temperatures and in the investigated HP-HT-regime. At high temperatures and ambient pressure, the quasicrystal decomposes. The application of mechanical stress at low temperatures yields to the same decomposition, the formation of Cd. A reaction of icosahedral Cd-Yb with traces of oxygen or water causing the decomposition seems reasonable, but a low-temperature instability of this binary quasi-crystal cannot be ruled out totally.

Micromethod for estimating adenosine deaminase activity in dried blood spots on filter paper.

1978 ◽  
Vol 24 (4) ◽  
pp. 591-594 ◽  
Author(s):  
A P Orfanos ◽  
E W Naylor ◽  
R Guthrie
Keyword(s):  
Adenosine Deaminase ◽  
Filter Paper ◽  
Severe Combined Immunodeficiency ◽  
Dried Blood Spots ◽  
Central Laboratory ◽  
Blood Spots ◽  
Adenosine Deaminase Activity ◽  
Immunodeficiency Disease ◽  
The Stability ◽  
Severe Combined Immunodeficiency Disease

Abstract We describe a fluorometric micromethod for measuring adenosine deaminase activity in dried blood spots on filter paper. Earlier methods require venipuncture and preparation of washed erythrocytes; in the present method, whole capillary blood, spotted on filter paper and mailed (dried) to a central laboratory, is used. The stability of the enzyme in dried blood on filter paper was assessed. The results were compared with those of a spectrophotometric method. The presence of serum appears not to affect the estimation of the activity and the method may be useful in early detection of severe combined immunodeficiency disease and hereditary hemolytic anemia.

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