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Biomedical subjects

A Lun

Publications and source records attributed to A Lun.

11 recordsLinked to original sources
PubMed1979

Hormonal induction of lactation: estrogen and progesterone in milk.

Estrogen and progesterone in milk during the first 21 days of induced and postpartum lactation in Holstein cows and heifers were estimated by assay procedures. Lactation was induced with estradiol-17 beta and progesterone treatment for 7 days. Estrogen and progesterone in induced lactations differed from concentrations in postpartum lactations. In early lactation estrogen was higher in postpartum milk (521 +/- 103 pg/ml on day 1) than in induced milk (336 +/- 46 pg/ml on day 1), but after day 7 the reverse was true (192 +/- 33 pg/ml and 233 +/- 32 pg/ml on day 7). Progesterone remained higher in induced lactation through the first 21 days than in postpartum lactation with the exception of day 19. Progesterone in postpartum milk increased from 4 +/- 1 ng/ml on day 1 to 11 +/- 2 ng/ml on day 21. Progesterone in induced milk showed greater fluctuation (11 +/- 3 ng/ml on day 1 and 22 +/- 9 ng/ml on day 3) but gradually decreased to 12 +/- 2 ng/ml on day 21 (11 +/- 2 ng/ml on day 21 of postpartum lactation).

Animals↗
PubMed1978

Avian encephalomalacia in Barbados, West Indies: a description of spontaneous field cases with feed analyses.

The clinical, necropsy and histopathological findings in four natural outbreaks of encephalomalacia are reported. Feed analyses implicated low levels of vitamin E as the probable cause of the condition. Treatment with vitamin E has proved to be very effective. The instability of vitamin E in animal feed ingredients during long periods of shipment into the Caribbean may be important in the pathogenesis of the disease.

Animal Feed↗
PubMed1978

[Influence of hypoxia and hyperoxia on the 2,3-diphosphoglycerate concentration in rat red blood cells].

The influence of hypoxia (pO2 = 85 mmHg) lasting 5 h, a strong single bleeding of the animals, and the effect of hyperoxia (pO2 = 745 and 1520 mmHg) lasting 24 and 5 h, respectively, on the 2.3-DPG concentration of red cells from rat has been studied. A distinct increase in 2.3-DPG concentration at hypoxia and bleedig, but no reliable alteration in hyperoxia were found. When bled and anemic animals are exposed to hyperoxia (24 h, pO2 = 745 mmHg, normal air pressure) there is also observed a rise of 2.3-DPG concentration, which is much less than in normoxia. A non-linear relationship was established between the change of 2.3-DPG concentration and the percentage of deoxyhemoglobin in the centralvenous blood.

Anemia↗
PubMed1976

[Autologous transfusion of erythrocytes with high or low concentration of 2,3-diphosphoglycerate. Survival rate and time and hemoglobin-oxygen affinity].

1. In human erythrocytes the 2.3 DPG concentration was increased three to fourfold of the norm as IPP re-suspension by an incubation time of four hours at 37 degrees C or as ACD-AG blood was lowered below 20% of the norm respectively. After an autologous transfusion the 24 hours' surviving rate and the apparent half survival time of cells as well as the affinity of haemoglobin to oxygen in the total blood were measured. 2. The 24 hours' surviving rate for fresh erythrocytes with increased 2.3 DPG and ATP concentration amounts to 73% and the apparent half survival time amounts to 6 days. If erythrocytes are stored for four weeks as IPP resuspension at 4 degrees C, the 24 hours' surviving rate is 59%. Erythrocytes from fresh ACD-AG blood with lowered 2.3 DPG and a normal ATP concentration have a 24 hours' surviving time of 85% and an apparent half survival time of 24 days. 3. After autologous transfusion of 400 ml of erythrocytes with increased 2.3 DPG concentration the P50 value of the total blood will increase by 3 mm of Hg, after administering 400 ml of erythrocytes with lowered 2.3 DPG concentration it will fall by 1.8 mm of Hg. 4. The findings are discussed in connection with the significance of the changes of affinity of haemoglobin to oxygen produced by 2.3 DPG for the oxygen supply of tissues and under the aspect of using stored blood with increased 2.3 DPG concentration for practical purposes.

Blood Transfusion, Autologous↗
PubMed1975

[Further improvement of the ACD-AG protective solution for blood. II. Behavior of the oxygen affinity of preserved blood in ACD-AG medium and in a protective solution with addition of pyruvate and xylitol and elevated Ph values].

The present paper deals with the behaviour of the oxygen transport function as well as the 2.3 DPG and ATP levels of erythrocytes during the storage in an ACD-AG solution. In the ACD-AG blood in P 50 fell from 20mm of Hg to values of 12 mm of Hg within 4 weeks of storage. The 2.3 DPG content had already fallen to values below 10% within a fortnight. Additions of xylitol (10 mM in the blood) and pyruvate (0.3 mM in the blood) will delay the decrease of P 50 and the 2.3 DPG content. Concerning the ATP behaviour there was no significant difference between ACD-AG blood and that with additions of xylitol and pyruvate. Up to a storage of a fortnight stored blood in the ACD-AG solution of xylitol and pyruvate will be equal to ACD-AG fresh blood as far as the parameter of oxygen transport function is concerned.

Adenosine Triphosphate↗
PubMed1975

[Further improvement of the ACD-AG protective solution for blood. III. Improvement of the oxygen transport function of erythrocytes in sorbitol xylitol pyruvate solutions with elevated Ph].

If the pH value in the ACD or in the ACD-AG storage solution is enhanced, the glucose in the autoclaving with undergo a caramelizing process. For this reason glucose was replaced by sorbite in the storage solutions with a pH value of 6.0 and additions of xylitol and pyruvate. The initial pH value in the blood amounted to 7.3. The content of 2.3 DPG of the erythrocytes remained fully preserved in the blood with sorbitol and additions of xylitol and pyruvate during the first 2 weeks of storage and decreased to 30% only in the third week. There were only slight amounts of 2.3 DPG in the ACD-AG blood at that time of storage. Up to the third week of storage the ATP content of erythrocytes as well as the haemoglobin level in the plasma revealed no essential differences between stored blood with sorbitol and xylitol as a substrate or glucose + xylitol respectively. The quick decrease of the ATP level to zero and the simultaneous strong increase of haemolysis in the sorbitol blood within the fourth week of storage is discussed in connection with a lowering of the NAD/NADH2 quotient. For the purpose of keeping the 2.3 DPG level of erythrocytes a storage solution with sorbite and xylitol (ASCX-AG-Pyr 10mM) seems to be well suited for a storing time of 2---3 weeks at first.

Adenosine Triphosphate↗