Direct Antiglobulin Reaction in ABO-Haemolytic Disease of the Newborn

The minimum number of IgG anti-A (or anti-B) molecules detectable on A or B red cells by the antiglobulin reaction was found to be the same—that is, about 150 molecules per red cell—with newborn as with adult cells. Furthermore, the ratio of anti-IgG bound to IgG anti-A (or anti-B) molecules was the same whether the anti-A (or anti-B) molecules were present on newborn or on adult cells and was similar to that found for anti-IgG bound to IgG anti-Rh.In 15 infants (11 group A, 4 group B) with haemolytic disease of the newborn due to ABO-incompatibility the amount of anti-A or anti-B on the red cells ranged from 0·25 to 3·5 μg antibody per ml red cells, corresponding to 90-1,320 antibody molecules per cell; only five infants had more than 0·55 μg antibody per ml of red cells. These amounts are far smaller than those found in most moderate or severe cases of Rh-haemolytic disease.It is concluded that the weak direct antiglobulin reactions observed in ABO-haemolytic disease are due simply to the fact that the number of anti-A (or anti-B) molecules on the infant''s red cells is at the lower limit of sensitivity of the test. Since ABO-haemolytic disease can be quite a severe process it seems probable that IgG anti-A and anti-B molecules are more effective than anti-Rh molecules in bringing about red cell destruction.     

Non-insulin dependent diabetic patients have increased glucose uptake in red blood cells

The kinetic characteristics of 3-O-methyl glucose (3-OMG) uptake were examined in red blood cells (RBC) from seven normal individuals (controls) and nine patients with non-insulin-dependent diabetes mellitus (NIDDM) treated with diet and oral hypoglycemic medication. Comparison of rates of 3-OMG uptake at 5 different substrate concentrations revealed significantly higher overall 3-OMG uptake in the diabetic group (P less than 0.0001). Kinetic parameters obtained for individual subjects showed there was not a significant difference in the Km between the diabetic (3.17 +/- 0.45 mM; mean +/- SE) and the control (2.46 +/- 0.25 mM) groups. However, Vmax was significantly increased (61%; P less than 0.025) in the diabetics (217.8 +/- 28.9 pmol/2 sec per 10(6) cells) compared to controls (135.2 +/- 15.6 pmol/2 sec per 10(6) cells). There was no correlation between HbA1C levels in the diabetic patients and Vmax values for 3-OMG uptake, suggesting that the increased hexose uptake was not accounted for simply by increased glycosylation in these cells. Glucose transport in RBC in hyperglycemic states may be a useful model for delineating the regulation of the non-insulin-mediated disposal of glucose in diabetes.     

Maternal origin of nucleated erythrocytes in peripheral venous blood of pregnant women

We studied the origin of nucleated red blood cells (NRBC) in peripheral venous blood samples from 40 pregnant women carrying a male fetus, using a technique that allows direct chromosomal analysis by in situ hybridisation on immunologically and morphologically classified cells. Samples from ten nulligravid women were studied as controls. NRBC were enriched by negative magnetic activated cell sorting (miniMACS) using anti-CD45 monoclonal antibody. NRBC were detected by alkaline phosphatase anti-alkaline phosphatase immunostaining using a monoclonal anti-glycophorin A antibody. The origin of the NRBC was determined by fluorescence in situ hybridisation using X and Y specific probes. NRBC were found in 37 of the 40 pregnant women at a range of 1 to 230 per 20 ml of venous blood and in 6 of the 10 controls at a range of 1 to 3 per 20 ml of venous blood. All NRBC detected in the pregnant women were evidently of maternal origin, and in the pregnant women the number of NRBC was significantly higher (P < 0.05) than in the controls. Pregnancy per se seems to induce the appearance of maternal NRBC in the circulation, and it cannot therefore be assumed that NRBC isolated from the maternal blood are of fetal origin on the basis of morphology alone. Discrimination of fetal NRBC must occur for prenatal diagnosis of fetal genetic disorders.     

The HLA-A mutation assay: improved technique and normal results

The HLA-A assay for detection of mutant lymphocytes has been modified, principally by incorporation of an overnight-incubation step which has resulted in improved immunoselection. For 83 estimations on cells from 21 normal individuals with a mean age of 35, the in vivo mutant frequency was 2.99 X 10(-5) +/- 1.48 X 10(-5) (mean +/- 1 SD). For 11 estimations on cells from 10 elderly individuals with a mean age of 78, the mutant frequency was significantly greater, being 7.16 X 10(-5) +/- 4.06 X 10(-5). Similar results were obtained when HLA-A2 or HLA-A3 mutants were enumerated. Mutant frequency measured at the HLA-A locus is almost an order of magnitude greater than that measured at the hypoxanthine phosphoribosyl transferase locus, but at least the major part of this difference is likely to be due to factors other than a difference in genetic stability between the two loci.     

Late midtrimester medical pregnancy terminations: three different procedures with prostaglandin F2 alpha and laminaria tents

One hundred twenty eight women underwent midtrimester induced abortion with: 1) combined regimen of intramniotic prostaglandin (PG) F2a injection and intracervical laminaria tents (group A, 50 women), 2) intramniotic PGF2a injection only (group B, 51 women) and 3) laminaria tents followed by intracervical PGF2a tablets insertion (group C, 27 women). The mean induction-abortion time (+/- SE) was 24.9 +/- 1.7 hours for group A, 28.2 +/- 2.2 hours for group B (p greater than 0.05) and 42.1 +/- 3.4 hours for group C, significantly longer than goup A and B (p less than 0.001 and p less than 0.01 respectively). In 48 hours 98% of the patients of group A, 90% of group B (p less than 0.05) and 59% of group C (p less than 0.001) completed the abortion procedure. Parous women of group A and B presented similar induction - abortion time, while in nulliparous the use of laminaria shortened the abortion procedure significantly (p less than 0.05). The complications rate was low. In conclusion, the intracervical PGF2a insertion is a simple but very slow abortion procedure with high failure rates. The intramniotic PGF2a injection is a successful method for late midtrimester medical pregnancy termination and the concurrent use of laminaria tents shortens the abortion procedure, particularly in nulliparous, reduces the number of prostaglandins' reinjections and increases the incidence of successful abortion within 48 hours.     

Lipid peroxidation and active calcium transport in inside-out vesicles of red blood cells from preeclamptic women

We previously reported that in preeclampsia Ca-ATPase activity diminishes about 50% in red blood cells, myometrium and syncitiotrophoblast plasma membranes. In this work, we measured the active Ca++ uptake by inside-out vesicles of human red blood cells from preeclamptic and normotensive pregnant women. Active calcium uptake by the vesicles was diminished by 49+/-3% in the preeclamptic women as compared to the gestational controls ( 8.06 +/- 0.11 nmol Ca++/mg protein min, gestational controls; 4.08 +/- 0.1 nmol Ca++/mg protein min, preeclamptics). This lowered calcium uptake correlates well with the lowered Ca-ATPase activity found in the red blood cells ghosts of the preeclamptic women (17.05 +/- 0.96 nmol Pi/mg protein min, gestational controls; 8.85 +/- 0.45 nmol Pi/mg protein min, preeclamptics). The reduced calcium uptake and Ca-ATPase activity of the red cell membranes both appear to be associated with a high level of lipid peroxidation. Thus there is a diminution in the active transport of calcium in the red blood cells of preeclamptic women. If this also occurs in other cell types of the preclamptic women, it could result in an increase in their cytosolic calcium concentration which might be responsible, in part, for some of the symptoms of this disease.     

O型孕妇产前IgG血型抗体效价与新生儿溶血病的相关性

目的:探讨O型孕妇产前IgG血型抗体效价与新生儿溶血病(HDN)的相关性。方法:选择2013年1月至2015年12月期间,在我院分娩的夫妻ABO血型不合的O型Rh(D)阳性孕妇432例及新生儿为研究对象,观察孕妇血清IgG抗体效价情况,新生儿HDN发病情况,并分析二者相关性。结果:432例孕妇中血清IgG抗A(B)效价大于或等于1:64的有189例,占43.75%,随IgG抗A(B)效价升高,孕妇比例逐渐减少。随孕次增加,孕妇血清IgG抗A(B)效价逐渐增高,各组孕妇血清IgG抗A(B)效价比较有统计学差异(P0.05)。随年龄增加,孕妇血清IgG抗A(B)效价逐渐增高,各组孕妇血清IgG抗A(B)效价比较有统计学差异(P0.05)。随IgG抗A(B)效价升高,HDN发生率显著升高,各组比较有统计学差异(P0.05)。等级相关检验显示,孕妇血清IgG抗A(B)与HDN发生呈正相关(r=0.732,P0.05)。结论:O型孕妇产前IgG血型抗体是引起HDN的主要原因,其水平与HDN呈正相关,值得临床重视。     

Somatomedin levels in the diagnosis and therapy of growth hormone deficiency

Serum somatomedin-C (SM-C) and somatomedin (SM) concentrations were measured by, respectively, radioimmuno (SM-C RIA) and radioreceptor assays (SM RRA) in 3 groups of children with short stature. The patient population was different from previously reported series in that it was urban Brazilian, low income, and significantly older. Group A consisted of 6 male and 3 female children, aged 7.7-16.0 years, whose average peak plasma immunoreactive growth hormone (GH) was above 10 ng/ml. Group B contained 8 male and 5 female untreated GH-deficient patients, ranging in age from 9.5 to 21.0 years. In Group C there were 4 male and 1 female GH-deficient subjects treated with I.M. injections of GH (0.1 U/kg) from 1 month to 7 years. The mean +/- SE basal RIA SM-C (ng/ml) concentrations were significantly lower in groups B (34.2 +/- 8.8) and C (43.8 +/- 13.7) than A (214.3 +/- 42.7): A X B, P less than 0.001 and A X C, P less than 0.02. Likewise the mean +/- SE basal RRA SM (ng/ml) concentrations were significantly lower in groups B (78.9 +/- 17.6) and C (90.8 +/- 19.3) than group A (316.3 +/- 43.0): A X B, P less than 0.001 and A X C, P less than 0.002. A significant linear correlation was observed between RIA and RRA in group B (r = 0.84; P less than 0.001) and C (r = 0.96; P less than 0.01), but not for A (r = 0.61; P greater than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

A monoclonal antibody with potential for aiding non-invasive prenatal diagnosis: utility in screening of pregnant women at risk of preeclampsia.

The development of a non-invasive method of prenatal diagnosis in maternal blood has been the goal of our investigations during the last years. We have developed several anti-CD71 monoclonal antibodies and optimized a protocol for the isolation of nucleated red blood cells (NRBC) from peripheral maternal blood. The enhanced traffic of fetal erythroblasts into the maternal circulation in preeclampsia has been investigated by several groups. In this study, we compared one of our antibodies, 2F6.3, with a commercial anti-CD71 antibody in blood samples from pregnant women suffering pregnancy-induced hypertension (PIH) and in a control group of pregnant women without clinical features suggestive of an increased risk of developing preeclampsia. The mAb 2F6.3, developed by our group, has succeeded in isolating a significantly higher number of erythroblasts with less maternal cell contamination than the commercial antibody in both women with PIH and in the control group (p<0.01; Wilcoxon Signed Ranks Test). Fluorescence in situ hybridization analysis also demonstrated that 2F6.3 is a better antibody for the isolation of fetal NRBC in maternal blood than the commercial anti-CD71 antibody.     

Internalization and cycling of the T cell antigen receptor. Role of protein kinase C

The dynamics of the T cell antigen receptor on a murine antigen specific T cell hybridoma have been analyzed using a monoclonal anti-receptor antibody. When this antibody, A2B4-2, is bound to surface receptors, no internalization is seen at 4 degrees C. Upon warming to 37 degrees C, between 20 and 30% of the antibody molecules are internalized over 20-30 min as measured by sensitivity to external acid. This level of internalization is identical if monovalent Fab fragments are used. In contrast, cross-linking of the anti-receptor antibody with a second antibody leads to rapid internalization of 100% of prebound surface A2B4-2. Phorbol 12-myristate 13-acetate (PMA) leads to the rapid internalization of up to 65% of the surface A2B4-2 or A2B4-2 Fab fragments. This effect requires protein kinase C and can be completely inhibited by depleting this kinase from the cells by long term treatment with high doses of PMA. Pretreatment of the T cells with PMA leads to a 40-50% drop in surface T cell antigen receptor expression. Despite the loss of surface receptors, the uptake of A2B4-2 in PMA-treated cells at 37 degrees C is identical to that seen in control cells. The total uptake of A2B4-2 at 37 degrees C is 25-30% greater than the number of surface receptors in control cells and about 100-150% greater than the number of surface receptors in PMA-treated cells. At steady state the percentage of total A2B4-2 on the cell surface is 75% for control cells and 38% for PMA-treated cells. The good agreement of these numbers with the percent internalization of a cohort of surface receptors suggests that all receptors are constantly cycling. The effect of PMA is to alter the kinetic parameters of this cycling, thus changing the steady state distribution of receptors between the plasma membrane and internal, presumably endosomal compartments. Measurement of initial rates of internalization suggests that the PMA effect can be largely explained by an increase in the internalization rate constant.     

Cholesterol synthesis in the perfused liver of pregnant hamsters

Pregnancy is a risk factor for the development of cholesterol gallstones. In pregnant women, biliary cholesterol saturation and secretion are increased. To investigate whether this was due to increased cholesterol synthesis, we studied hepatic cholesterol synthesis in Syrian Golden hamsters. Female controls and animals 10- to 14-days pregnant were studied. The studies were performed in the in situ perfused hamster liver. Cholesterol synthesis was determined by measuring the incorporation of 3H2O added to the perfusate into hepatic, perfusate, and bile cholesterol during a 90-min period. In both pregnant groups, bile flow decreased significantly, but biliary cholesterol concentration increased only in the 14-day pregnant group. The cholesterol synthesis rate averaged (mean +/- SD) 172 +/- 27, 127 +/- 37, and 552 +/- 79 nmol X hr-1 X g liver-1 in controls, 10-day, and 14-day pregnant animals, respectively. The 14-day pregnant animals secreted a markedly higher fraction (47.3 +/- 11.3 vs. 11.1 +/- 13.4%; P less than 0.01) of newly synthesized cholesterol into bile but not into perfusate. Chenodeoxycholate, but not cholate, synthesis rate was decreased in both pregnant groups. We conclude from our studies that hepatic cholesterol synthesis increases towards the end of pregnancy in the hamster and that more newly synthesized cholesterol is secreted into bile at that time. This could at least partially explain the increased biliary cholesterol saturation and secretion observed in women in the third trimenon, and explain pregnancy as a risk factor in the development of cholesterol gallstones.     

Subclass specificity of the Fc receptor for human IgG on K562

The erythroleukemic cell line K562 bears a 40-kDa Fc receptor (Fc gamma RII) serologically related to and with a similar molecular weight as the Fc gamma R present on a broad range of leukocytes. The human IgG subclass specificity of the Fc gamma R on K562 was investigated using IgG aggregates of defined size, obtained from purified human myeloma proteins. The monoclonal antibody IV.3, which reacts with the Fc gamma RII present on various cell types, totally prevented binding of 125I-IgG2 trimers to K562. Experiments with radiolabeled IgG2 trimers showed that K562 cells bound a mean of 156,764 +/- 9895 molecules per cell with an association constant (Ka) of 1.8 +/- 0.7 X 10(8) M-1. Similar results were obtained with IgG3 oligomers. IgG3 and IgG2 trimers were about two- to threefold more effective in inhibiting binding of 125I-IgG2 trimers to K562 than IgG1 and IgG4 trimers. These results were confirmed by inhibition experiments using IgG monomers. The subclass specificity of the Fc gamma RII on K562 (i.e., IgG2 = IgG3 greater than IgG1 = IgG4) is quite distinct from the one reported for the Fc gamma RI and III of human cells (i.e., IgG1 = IgG3 greater than IgG4 and IgG2).     

Morphometric analysis of follicular dynamics in pregnant and pseudopregnant rats

Morphometric analysis of the follicle population greater than or equal to 100 X 10(5) micron 3 or a mean diameter of greater than or equal to 275 micron and assessment of the rate of atresia in ovaries of pregnant and pseudopregnant rats revealed no evidence for the presence of rhythmic follicular maturation during the prolonged dioestrous period. During the first 4-5 days of the dioestrous period, follicles developed to preovulatory size (volume class 5, i.e. greater than or equal to 1000 X 10(5) micron 3 = diam. greater than or equal to 576 micron) reaching the normal number of ovulating follicles in cyclic animals in pregnant rats, but only half that number in pseudopregnant rats. These follicles collapsed on the 5th to 8th days of the dioestrous period and full numbers of preovulatory follicles were not found thereafter until the end of pregnancy and pseudopregnancy. Follicles of smaller sizes (classes 1-4: 100-999 X 10(5) micron 3), however, were present throughout the prolonged dioestrous period. The rate of atresia in the follicle population had increased by the 2nd day and remained from then on at 26.5 +/- 4.5% in the pregnant and 34.3 +/- 1.9% in the pseudopregnant rats. Atretic follicles in the advanced stages of atresia, mostly derived from follicles of classes 1-3, persisted and accumulated at the end of the dioestrous period. The continuous presence of follicles and the constant rate of atresia during the dioestrous period indicate continuous follicular replacements and refute the idea of follicular quiescence during pregnancy and pseudopregnancy. Copulation and electrical stimulation of the cervix seemed to reduce the formation of the new crop of follicles the next morning and the pool of small antral follicles normally maintained after oestrus in cyclic animals. Nevertheless, the smaller crop and pool of follicles seemed able to provide a sufficient number of preovulatory follicles at the end of pregnancy and a sufficient number of ovulations at the end of pseudopregnancy.     

Lea-active heptaglycosylceramide, a hybrid of type 1 and type 2 chain, and the pattern of glycolipids with Lea, Leb, X (Lex), and Y (Ley) determinants in human blood cell membranes (ghosts). Evidence that type 2 chain can elongate repetitively but type 1 chain cannot

Two major glycolipids reactive with the monoclonal anti-Lea antibody have been isolated from human blood cell membranes. One component was identified as lactofucopentaosyl(II)ceramide and the other as a ceramide heptassaccharide with the structure described below: (formula; see text) The structure includes the Lea determinant (type 1 chain) linked to lactoneotetraosylceramide (type 2 chain); thus, it is regarded to be a hybrid between type 1 and 2 chain. In addition, a minor component having the thin-layer chromatographic mobility of a ceramide nonasaccharide, which was reactive to anti-Lea antibody, was detected. No other component with a thin-layer chromatographic mobility slower than the above components and reactive to the anti-Lea antibody was detected. In contrast, a series of slowly migrating glycolipids having X (Lex) determinant (Gal beta 1----4(Fuc alpha 1----3)GlcNAc) was detected. A similar series of long chain glycolipids having Y (Ley) determinant (Fuc alpha 1----2Gal beta 1----4(Fuc1----3)GlcNAc) was detected in human blood cells; in contrast, only one major Leb glycolipid was found with the mobility of a ceramide hexasaccharide. No glycolipid with a long carbohydrate chain composed exclusively of type 1 chain was detected. Thus, chain elongation may proceed through type 2 chain, but not through type 1 chain. Lea and X (Lex) haptens are distributed equally among blood group A, B, and O red blood cells, whereas the quantity of Leb and Y (Ley) haptens is much lower in A and B blood cells than in O blood cells.     

Antigenicity of erythrocytes as analyzed in terms of their cross-reactivity.

The antigenicity of human erythrocytes of four different ABO blood groups and sheep erythrocytes of unknown blood type from different individual sheep were analyzed in terms of their cross-reactivity with antibody-producing cells (plaque-forming cells, PFC) and serum antibody in immunized C57BL/6 and C3H/He mice. The antigenicity of human erythrocytes of different ABO blood groups in the C57BL/6 mice, as determined by the number of specific PFC, was, in decreasing order, AB = A greater than B = O (p less than 0.005). The efficiency of immunogenicity of the human erythrocytes in terms of their cross-reactivity with PFC was, in order, AB = A = B greater than O, and the degree of reactinogenicity was, in order, AB greater than A greater than B greater than O. The order of antigenicity of sheep erythrocytes from different animals, SRBC No. 1 - No. 6, was No. 1 (= No. 2) greater than No. 3 = No. 4 = No. 5 greater than No. 6 in C57BL/6 mice and No. 1 = No. 2 = No. 3 = No. 4 = No. 6 greater than No. 5 in C3H/He mice, determined by the number of specific PFC (p less than 0.01). The cross-reactivity of SRBC No. 1 - No. 6 with PFC demonstrates that the order of immunogenicity of SRBC was No. 1 = No. 2 = No. 3 = No. 4 = No. 5 greater than No. 6 in C57BL/6 mice and No. 1 = No. 2 = No. 3 = No. 4 = No. 6 greater than No. 5 in C3H/He mice, and that of their reactinogenicity was No. 1 greater than No. 2 =No. 3 = No. 4 = No. 5 greater than No. 6 in C57BL/6 mice and No. 1 greater than No. 4 = No. 6 greater than No. 2 = No. 3 greater than No. 5 in C3H/He mice. The cross-reactivity at the antibody level was indicative of the immunologic characteristics of blood cells of low antigenicity (human group O erythrocytes and SRBC No. 5 and No. 6). SRBC No. 5 and No. 6 were somewhat opposed to each other regarding antigenicity in C57BL/6 and C3H/He mice. This signifies the presence of different immunogenic components on SRBC No. 5 and No. 6. The production of anti-SRBC No. 1 antibody reached its peak on the third day after secondary immunization. That of anti- SRBC No. 1, cross-reactive with SRBC No. 6, occurred after a longer latent period, reaching its peak on day 6. This indicates that SRBC No. 1 possesses more than one kind of immunogenic component or immunogenic determinant group on its surface.     

Quantities of individual aminoacyl-tRNA families and their turnover in Escherichia coli.

The cellular content of all 20 aminoacyl-tRNA species was determined in small cultures of Escherichia coli by labeling cells with 3H-amino acids and extraction of 3H-amino acid-labeled nucleic acid by standard procedures. Of 3H-amino acid-labeled material, 25 to 90% was identified as 3H-aminoacyl-tRNA by the following criteria: sensitivity to base hydrolysis with expected kinetics; association of 3H counts released by base treatment of the 3H-amino acid-labeled nucleic acid with amino acid standards upon paper chromatography of the hydrolysate; and changes in the amount of 3H-amino acid-labeled nucleic acid recovered from cells as a function of time. Individual aminoacyl-tRNA content was determined with as few as 8 X 10(7) to 4 X 10(8) E. coli cells. Although the total number of aminoacyl-tRNA molecules per cell varied only by 10 to 20% among various strains of E. coli, some individual aminoacyl-tRNA families varied two- to threefold among strains. For a given amino acid, the number of aminoacyl-tRNA molecules per cell in E. coli strain K38 growing with a doubling time of 60 min varied from 730 (glutamyl-tRNA) to 7,910 (valyl-tRNA) with a mean value of 3,200. The total number of aminoacyl-tRNA molecules per cell (6.4 X 10(4)) in E. coli K38 was 5.5-fold higher than the number of ribosomes and was equal to 84% of the amount of elongation factor Tu molecules per cell. The ratio of aminoacyl-tRNA to synthetase for 10 amino acids varied from about 1 to 15 with a mean value of 4.7. The turnover of individual aminoacyl-tRNA families in E. coli cells was estimated to be in the range of 1.7 to 8.1 s-1 with a mean value of 3.7 s-1. An estimate of minimum in vivo molecular activity of aminoacyl-tRNA synthetases gives values of 2 to 48 s-1 for individual enzymes.     

Isotope tracer measures of meal fatty acid metabolism: reproducibility and effects of the menstrual cycle

Oxidation and adipose tissue uptake of dietary fat can be measured by adding fatty acid tracers to meals. These studies were conducted to measure between-study variability of these types of experiments and assess whether dietary fatty acids are handled differently in the follicular vs. luteal phase of the menstrual cycle. Healthy normal-weight men (n = 12) and women (n = 12) participated in these studies, which were block randomized to control for study order, isotope ([3H]triolein vs. [14C]triolein), and menstrual cycle. Energy expenditure (indirect calorimetry), meal fatty acid oxidation, and meal fatty acid uptake into upper body and lower body subcutaneous fat (biopsies) 24 h after the experimental meal were measured. A greater portion of meal fatty acids was stored in upper body subcutaneous adipose tissue (24 +/- 2 vs. 16 +/- 2%, P < 0.005) and lower body fat (12 +/- 1 vs. 7 +/- 1%, P < 0.005) in women than in men. Meal fatty acid oxidation (3H2O generation) was greater in men than in women (52 +/- 3 vs. 45 +/- 2%, P = 0.04). Leg adipose tissue uptake of meal fatty acids was 15 +/- 2% in the follicular phase of the menstrual cycle and 10 +/- 1% in the luteal phase (P = NS). Variance in meal fatty acid uptake was somewhat (P = NS) greater in women than in men, although menstrual cycle factors did not contribute significantly. We conclude that leg uptake of dietary fat is slightly more variable in women than in men, but that there are no major effects of menstrual cycle on meal fatty acid disposal.     

Prostaglandin A1 metabolism and inhibition of cyclic AMP extrusion by avian erythrocytes

Prostaglandins (PG) inhibit active cyclic AMP export from pigeon red cells, PGA1 and PGA2 most potently (Brunton, L.L., and Mayer, S.E. (1979) J. Biol. Chem. 254, 9714-9720). To probe the mechanism of this action of PGA1, we have studied the interaction of [3H]PGA1 with suspensions of pigeon red cells. The interaction of PGA1 with pigeon red cells is a multistep process of uptake, metabolism, and secretion. [3H] PGA1 rapidly enters red cells and is promptly metabolized (Vmax greater than or equal to 1 nmol/min/10(7) cells) to a compound(s) that remains in the aqueous layer after ethylacetate extraction. The glutathione-depleting agent, diamide, inhibits formation of the PGA1 metabolite. In agreement with the order of potency of other prostaglandins to inhibit cAMP efflux (A much greater than E congruent to B greater than F), PGA2 forms a polar adduct whereas prostaglandins E2, B1, and F2 alpha do not. The red cells secrete the polar metabolite of PGA1 by a saturable mechanism (at 37 degrees C, Km congruent to 0.6 microM, Vmax congruent to 0.5 pmol/min/10(7) cells) that lowered temperatures inhibit (Eact congruent to 21 kcal/mol). Because uptake and metabolism progress with much greater rates than metabolite secretion, red cells transiently concentrate the polar compound intracellularly. Onset and reversal of inhibition of cyclic AMP export by PGA1 coincide with accumulation and secretion of PGA1 metabolite, suggesting that the polar metabolite acts at an intracellular site to inhibit cyclic AMP efflux. In the accompanying Appendix, we present chromatographic and amino acid analyses demonstrating that the polar metabolite is a glutathione adduct of PGA1.     

Myofibril and sarcoplasmic reticulum changes with exercise and growth

The intent of this study was to observe the effects of different treadmill running programs upon selected biochemical properties of soleus muscle from young rats. Young 10 day litter-mates were assigned to endurance (E), spring (S) and control (C) groups. Each was partitioned into either 21 or 51 day exercising groups and 10 day controls. For C the myofibril ATPase activity at 21 and 51 days were lower than 10 day activity (p less than or equal to 0.05). In the 51 day E group ATPase activity (0.378 +/- 0.009 mumol Pi X mg-1 X min-1) was greater than at 10 and 21 days (0.307 +/- 0.006 and 0.323 +/- 0.008 mumol Pi X mg-1 X min-1) (p less than or equal to 0.05). No change occurred in the S group from 10 to 21 and 51 days (p greater than or equal to 0.05). Both the 21 and 51 day S (0.318 +/- 0.011 and 0.399 +/- 0.010 mumol Pi X mg-1 X min-1) and E (0.323 +/- 0.008 and 0.378 +/- 0.009 mumol Pi X mg-1 X min-1) groups had higher activity compared to the C group (0.193 +/- 0.029 and 0.172 +/- 0.031 mumol Pi X mg-1 X min-1) (p less than or equal to 0.05). Maturation (10--51 day) resulted in a lowered sarcoplasmic reticulum (SR) yield and Ca2+ binding (p less than or equal to 0.05) while Ca2+ uptake ability did not change (p greater than or equal to 0.05). SR yield, Ca2+ binding and uptake were not altered with S training (p greater than or equal to 0.05). The E training resulted in greater Ca2+ uptake at 51 days compared to C and S (p less than or equal to 0.05), with no change in Ca2+ binding (p greater than or equal to 0.05). The data suggest that E training alters the normal development pattern of young rat soleus muscle.     

Effects of lactational and reproductive status on ovarian follicular waves in llamas (Lama glama)

The effects of lactational status and reproductive status on patterns of follicle growth and regression were studied in 41 llamas. Animals were examined daily by transrectal ultrasonography for at least 30 days. The presence or absence of a corpus luteum and the diameter of the largest and second largest follicle in each ovary were recorded. Llamas were categorized as lactating (N = 16) or non-lactating (N = 25) and randomly allotted to the following groups (reproductive status): (1) unmated (anovulatory group, N = 14), (2) mated by a vasectomized male (ovulatory non-pregnant group, N = 12), (3) mated by an intact male and confirmed pregnant (pregnant group, N = 15). Ovulation occurred on the 2nd day after mating with a vasectomized or intact male in 26/27 (96%) ovulating llamas. Interval from mating to ovulation (2.0 +/- 0.1 days) and growth rate of the preovulatory follicle (0.8 +/- 0.2 mm/day) were not affected by lactational status or the type of mating (vasectomized vs intact male). Waves of follicular activity were indicated by periodic increases in the number of follicles detected and an associated emergence of a dominant follicle that grew to greater than or equal to 7 mm. There was an inverse relationship (r = -0.2; P = 0.002) between the number of follicles detected and the diameter of the largest follicle. Successive dominant follicles emerged at intervals of 19.8 +/- 0.7 days in unmated and vasectomy-mated llamas and 14.8 +/- 0.6 days in pregnant llamas (P = 0.001). Lactation was associated with an interwave interval that was shortened by 2.5 +/- 0.05 days averaged over all groups (P = 0.03). Maximum diameter of anovulatory dominant follicles ranged from 9 to 16 mm and was greater (P less than 0.05) for non-pregnant llamas (anovulatory group, 12.1 +/- 0.4 mm; ovulatory group, 11.5 +/- 0.2 mm) than for pregnant llamas (9.7 +/- 0.2 mm). In addition, lactation was associated with smaller (P less than 0.05) maximum diameter of dominant follicles averaged over all reproductive statuses (10.4 +/- 0.2 vs 11.7 +/- 0.3 mm). The corpus luteum was maintained for a mean of 10 days after ovulation in non-pregnant llamas and to the end of the observational period in pregnant llamas. The presence (ovulatory non-pregnant group) and persistence (pregnant group) of a corpus luteum was associated with a depression in the number of follicles detected and reduced prominence of dominant follicles (anovulatory group greater than ovulatory non-pregnant group greater than pregnant group).(ABSTRACT TRUNCATED AT 400 WORDS)