FACTORS GOVERNING THE STIMULATION OF EMBRYONIC CHICK CARTILAGE BY SOMATOMEDIN

1976 ◽  
Vol 83 (2) ◽  
pp. 259-268 ◽  
Author(s):  
A. C Herington ◽  
L. S. Phillips ◽  
W. H. Daughaday
Keyword(s):  
Human Serum ◽  
Incubation Time ◽  
Dry Weight ◽  
Good Precision ◽  
Embryonic Chick ◽  
Prolonged Incubation ◽  
Significant Stimulation ◽  
Normal Human ◽  
Assay Precision ◽  
Stimulation Of

ABSTRACT In these studies of the stimulation of embryonic chick pelvic rudiments by somatomedin (Sm) in serum, we have found that cartilage weight and duration of cartilage exposure to serum determine the stimulation of cartilage by serum and the relative stimulation by Sm and by other non-Sm serum components, respectively. These factors are critical for the use of this system to measure Sm in serum. Initial experiments revealed that incorporation of sulfate (SO4) by cartilage incubated in buffer fell rapidly after 9 h and reached very low levels by 30 h. Incubation in 40 % normal human serum (NHS) produced significant stimulation of incorporation of SO4 after 4 h, and maintained at least initial levels of incorporation for 24 h. The greatest % stimulation by NHS over buffer was seen with prolonged incubation (44 h). However, specificity for Sm (discrimination between NHS and hypophysectomized human serum (HHS)) was greater with shorter incubation times. The potency of HHS was 11, 42 and 92 % of the potency of NHS following early, intermediate and late measurement of incorporation of SO4 by cartilage, respectively. The best overall results were obtained with intermediate incubation time and measurement of SO4 incorporation ((35S)-SO4 present for the final 5 h of a 25 h incubation), which allowed good precision (λ = 0.17) while maintaining satisfactory specificity for Sm. Since prolonged incubation with late measurement of SO4 incorporation allowed the greatest % stimulation by serum with little differentiation between NHS and HHS, stimulation of incorporation of SO4 under these conditions is apparently due to non-Sm factors present in both NHS and HHS. In addition to incubation time, cartilage stimulation by serum was also determined by cartilage weight. Lighter cartilage (from younger embryos) was associated with higher unstimulated incorporation of SO4 (P < 0.01), lower stimulation by added serum (P < 0.01), and inadequate assay precision (P < 0.05): satisfactory assays were generally obtained with cartilage rudiments weighing more than 0.7 mg (dry weight).

scholarly journals Studies on the Effects of Gaseous Ions on Plant Growth

1962 ◽  
Vol 45 (5) ◽  
pp. 879-895 ◽  
Author(s):  
Albert P. Krueger ◽  
Sadao Kotaka ◽  
Paul C. Andriese ◽  
Keyword(s):  
Plant Growth ◽  
Avena Sativa ◽  
Current Flow ◽  
Dry Weight ◽  
Stem Length ◽  
Ion Density ◽  
Measurable Difference ◽  
Significant Stimulation ◽  
Growth Increase ◽  
Stimulation Of

Exposure of Avena sativa seedlings to unipolar ionized atmospheres of either charge produced statistically significant stimulation of growth as measured by mean stem length, integral elongation, and dry weight. The extent of growth increase was related to the atmospheric ion density and this in turn determined the magnitude of current flow to ground. The minimal current measured in the ground circuit and capable of producing a measurable difference in growth was 4.3 to 4.6 x 10-13 amp/plant.

Cyclic AMP release from normal human thyroid slices in response to thyrotrophin

1980 ◽  
Vol 95 (3) ◽  
pp. 335-340 ◽  
Author(s):  
Stephen P. Bidey ◽  
Nicholas J. Marshall ◽  
Roger P. Ekins
Keyword(s):  
Cyclic Amp ◽  
Incubation Time ◽  
Thyroid Tissue ◽  
Human Thyroid ◽  
Dose Dependency ◽  
Incubation Periods ◽  
In Vitro Exposure ◽  
Normal Human ◽  
Stimulation Of

Abstract. Slice preparations of normal human thyroid tissue were incubated in vitro with TSH. The cyclic AMP contents of slices were determined at intervals up to 120 min, and cyclic AMP in the incubation medium was also estimated for each incubation period. Slice cyclic AMP levels were related both to incubation time and TSH dose. In response to 10 mU TSH/ml, slice cyclic AMP levels were maximal within 60 min, and were not significantly changed at 120 min. Cyclic AMP was detectable in the medium within 10 min of slice exposure to TSH, and increased throughout the initial 60 min of incubation. Cyclic AMP release during this period was dependent on both TSH dose and incubation time. Between 60–120 min, however, cyclic AMP release partially lost its TSH dose-dependency, and 0.5–5.0 mU TSH/ml were equipotent with respect to the final medium cyclic AMP level attained. Slices incubated without TSH released only small amounts of cyclic AMP, and maximal levels were attained within 20 min. In contrast to the adenylate cyclase response of thyroid membrane preparations, which was stimulated by NaF, suggesting that cyclic AMP release was not a result of the stimulation of damaged cells. These findings demonstrate the importance of cyclic AMP release from human thyroid slices, following in vitro exposure to TSH, and suggest that, after incubation periods such as are used for the functional biodetection of thyroid stimulators, the magnitude of cyclic AMP release may be of quantitative significance.

scholarly journals Evaluation of Bactericidal Action of Serum Collected from Paratyphoid Patients and Normal Human against Salmonella Paratyphi

2013 ◽  
Vol 12 (1) ◽  
pp. 71-75
Author(s):  
Md. Chhanaur Rabbee ◽  
Mohammad Shahriar ◽  
Mohiuddin Ahmed Bhuyian ◽  
Rishikesh Islam ◽  
Md. Asraful Islam
Keyword(s):  
Human Serum ◽  
Bactericidal Activity ◽  
Incubation Time ◽  
Normal Human Serum ◽  
Bacterial Suspension ◽  
Bactericidal Action ◽  
Alternative Pathways ◽  
Normal Human ◽  
The Mean ◽  
Paratyphoid Fever

A comparative study of susceptibility of clinical isolates of Salmonella Paratyphi to bactericidal action of S. Paratyphi infected human serum and uninfected human serum was investigated. Bactericidal action of S. Paratyphi infected human serum and uninfected human serum was assessed after incubating the bacterial suspension of S. Paratyphi with 40% of both infected and unifected human serum at various incubation times. Eight samples of S. Paratyphi infected serum from the patients diagnosed with paratyphoid fever were used. The investigation found that the serum killed S. Paratyphi both by classical and alternative pathways. Anti- S. Paratyphi antibodies for the bactericidal action of serum were examined by the assessment of bactericidal activity of non-immune normal human serum. Significant killing of S. Paratyphi by S. Paratyphi infected serum was investigated and the serum mediated killing was increased by increasing the incubation time. The mean growth declines gradually as the incubation time was increased. No noteworthy serum mediated killing was observed for normal human serum and inactivated (heat induced) S. Paratyphi infected serum. Dhaka Univ. J. Pharm. Sci. 12(1): 71-75, 2013 (June) DOI: http://dx.doi.org/10.3329/dujps.v12i1.16303

Growth hormone dependent human serum stimulation of thymidine and sulphate incorporation into embryonic chicken cartilage

1980 ◽  
Vol 94 (4) ◽  
pp. 480-488
Author(s):  
John Jennings ◽  
Fred Buchanan ◽  
Lynne Levitsky ◽  
John T. Garland
Keyword(s):  
Growth Hormone ◽  
Single Dose ◽  
Human Serum ◽  
Gh Deficiency ◽  
Serum Concentrations ◽  
Serum Stimulation ◽  
Embryonic Chicken ◽  
Normal Human ◽  
Normal Adults ◽  
Stimulation Of

Abstract. The embryonic chicken cartilage somatomedin bioassay was modified so that human serum stimulation of simultaneous [3H]methylthymidine and H2[35S]04 incorporation could be assessed. The assay consisted of a 6 h pre-incubation of 10 day pelvic rudiments in enriched buffer, followed by a 24 h incubation with buffer and low (0.5, 2 and 5% v/v) serum concentrations. Both labels were present for the final 6 h. Other modifications were shortening of washing, elimination of drying and weighing, and simplification of digestion. Normal human serum produced a linear log dose-response with these serum concentrations. Potency ratios in patients with GH deficiency were less than those of normal adults for both thymidine 0.39 ± 0.05 (mean ± sem, n = 16, range 0.22-0.71) vs. 0.90 ± 0.05 (n = 19, 0.62—1.36, P< 0.001) and for sulphate 0.40 ± 0.04 (0.15—0.65) vs. 94 ± 0.05 (0.61—1.29, P< 0.001). Potency ratios for both labels rose following administration of a single dose (0.2 IU/kg im) of hGH to 4 GH deficient children. The reliability of prediction of GH deficiency, reproducibility, and precision were similar to other Sm bioassays. The major advantages of these modifications were the ability to examine 2 cartilage metabolic processes simultaneously and the small amount of serum (350 μl) necessary for patient assays.

Comparison between the effects of FSH and LH on the steroidogenic pattern in isolated pre-ovulatory rat follicles

1985 ◽  
Vol 108 (4) ◽  
pp. 557-564
Author(s):  
Björn Carlsson ◽  
Jan-Owe Skånberg ◽  
Paul Roos ◽  
Torbjörn Hillensjö
Keyword(s):  
Time Course ◽  
Preovulatory Follicle ◽  
Prolonged Incubation ◽  
Significant Stimulation ◽  
Immature Rats ◽  
Ovulatory Follicles ◽  
Stimulation Of

Abstract. The effects of purified FSH preparations from three different species (ovine, human, rat) on the steroidogenic pattern in isolated pre-ovulatory follicles of PMSG-treated immature rats were examined and compared to the effects of LH (ovine, human). Steroids were analyzed by RIA. During 6 h incubation, all three FSH preparations in a concentration range from 10–100 ng/ml caused a significant increase in progesterone (P), testosterone (T), and oestradiol (E2) accumulation. With LH a significant increase in steroid accumulation was seen in a concentration of 1 ng/ml. The time-course of stimulation by hFSH and hLH in a concentration of 10 ng/ml showed no difference in steroidogenic response between the two hormones, with a significant stimulation of steroids within 2 h. During prolonged incubation (6–8 h), accumulation of T was measured in the presence or absence of unlabelled 17α-hydroxyprogesterone. Follicles exposed to LH did not increase their T formation, while follicles incubated in plain medium or in the presence of oFSH increased their T formation. In a concentration of 100 ng/ml hFSH showed a tendency to reduce maximal T production. These results suggest that FSH alone in physiological doses may stimulate T and E2 production in the preovulatory follicle.

INHIBITION BY HUMAN SERUM OF THE ADIPOKINETIC EFFECT OF A HUMAN PITUITARY LIPID-MOBILIZING FACTOR

1972 ◽  
Vol 71 (3) ◽  
pp. 443-453 ◽  
Author(s):  
Olav Trygstad ◽  
Irene Foss
Keyword(s):  
Human Serum ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
Inhibitory Effect ◽  
Disc Electrophoresis ◽  
Inhibitory Protein ◽  
Human Pituitary ◽  
Albumin Fraction ◽  
Pituitary Glands ◽  
Normal Human

ABSTRACT A lipid-mobilizing factor (LMF) with an adipotrophic effect in human and animal fat tissue has been prepared from human pituitary glands. The addition of normal human serum to LMF reduced its lipolytic effect, and it was completely abolished by serum from a group of obese patients, whereas the lipolysis was not influenced by serum from patients with generalized lipodystrophy. By DEAE-cellulose chromatography of human serum the inhibitory effect on LMF was found to be present in a protein fraction less acidic than the main serum albumin fraction. The inhibitory fraction was deprived of some contaminants by Sephadex gel filtration. Disc electrophoresis demonstrated the presence of three components in the inhibitory protein (IP), and they were identified as albumin, transferin, and haemopexin by immuno-electrophoresis. Precipitation of these proteins by their rabbit antisera demonstrated that the inhibitory effect was present in the albumin fraction. Insulin like activity was not observed in IP. A protein binding of LMF by IP could not be demonstrated. Incubation at 37°C for one hour of a mixture of LMF and IP eliminated the electrophoretic picture of LMF. It is concluded that the inhibitory effect of human serum may be due to proteolysis of LMF.

Evaluation of a commercially available radioimmunoassay kit for measurement of doxorubicin in plasma.

1982 ◽  
Vol 28 (1) ◽  
pp. 119-121 ◽  
Author(s):  
E Piall ◽  
G W Aherne ◽  
V Marks
Keyword(s):  
Human Serum ◽  
Normal Human Serum ◽  
Nonspecific Effects ◽  
Normal Human ◽  
Doxorubicin Concentration

Abstract We evaluated a commercially available (Diagnostic Biochemistry Inc.) doxorubicin 125I radioimmunoassay kit. This kit gave a high apparent doxorubicin concentration (greater than 12 micrograms/L), which was not linearly related to dilution, for two pools of normal human serum and plasma and also for samples collected from patients before they received the drug. In contrast, a doxorubicin 3H radioimmunoassay developed by us gave a low blank (2 micrograms/L), which was linearly related to dilution, for the same pools and patients' samples. Doxorubicin concentrations in the plasma of patients receiving the drug were compared by the two methods; the kit gave results five- to 10-fold those obtained with our assay. High nonspecific interference by serum and plasma as measured by the 125I radioimmunoassay must therefore be borne in mind by users of the kit, and we suggest that results should be corrected for these nonspecific effects.

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