The potential for immunohistochemical detection of progesterone receptors (PRs) in routinely formalin-fixed and paraffin-embedded cancer tissues by use of the monoclonal antibody Mi 60-10 (mPR1, Dianova GmbH, Hamburg) was evaluated. The PR content of breast cancer tissue was investigated in 170 cases. A positive reaction to Mi 60-10 was found exclusively in the nuclei of benign or malignant epithelial cells. The distribution of PRs was heterogeneous. Immunohistochemical reaction was scored by multiplying the percentage of positive tumour cells by their prevalent degree of staining (Immunoreactive Score or IRS). The IRS values of formalin-fixed tissues (n = 170) were compared with those in snap frozen tissues (n = 82), with the PR content assayed by a DCC (dextran-coated charcoal) method (n = 170), with histopathological grading according to Bloom and Richardson and with the menopausal status of the patient. There was an acceptable ranked correlation (r = 0.74) between IRS in formalin-fixed and paraffin-embedded parts and snap frozen parts of the same carcinoma. A good correlation (r = 0.72) was also found, when the semiquantitative results of immunohistochemical PR detection in formalin-fixed and paraffin-embedded tissues were compared to PR concentrations measured by a DCC method in tumor cytosols. There was an 80% concordance between the two methods for qualitative discrimination of PR-negative and PR-positive carcinomas. IRS correlated significantly with the degree of histological differentiation of the tumors (P less than 0.001) but not with the menopausal status of the women (P greater than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗

PubMed1989

Influence of blood pressure, heart rate, age, and sex on concentrations of atrial natriuretic factor and cyclic GMP in 124 volunteers.

The significance of increased atrial natriuretic factor (ANF) in relation to blood pressure and age is still controversial. We investigated the influence of blood pressure, age, and some other variables on ANF and its putative second messenger, cGMP. Samples for ANF and cGMP detection were taken from 124 ostensibly healthy individuals who were donating blood. Samples were also collected from 27 volunteers before and after blood donation, to study the influence of bleeding. During blood donation, ANF increased from 78.9 to 87.4 ng/L (P = 0.0035), whereas cGMP remained unchanged. ANF concentrations in 124 healthy individuals, corrected for the influence of bleeding, were 61.5 (SD 26.1) ng/L, with a 95% confidence interval of 10.0 to 112.1 ng/L. Mean cGMP concentrations in plasma were 2.9 (SD 1.45) nmol/L, with a 95% confidence interval of 0.4 to 5.75 nmol/L. Multivariance analysis revealed no significant influence of blood pressure, age, heart rate, or sex on concentrations of either ANF or cGMP in plasma.

Adult↗

PubMed1989

Adaptation of the uterine arcade in rats to pregnancy.

In order to study the adaptation of the uterine arterial system to pregnancy we measured vascular dimensions and other growth related data (DNA content and [3H]thymidine incorporation rate) on excised uterine arcades, pressurized to 100 mmHg, of rats before and during pregnancy (day 8, 18 and 21 of gestation). The vascular conductance of the arcade was calculated using a numerical method. In order to investigate the response of the arcade to flow impairment during early pregnancy, the same measurements were repeated on uterine arcades from pregnant animals (day 21 of gestation), where the left uterine artery had been ligated on day 8 of pregnancy. In adult virgin rats, the uterine arcade was 0.3 +/- 0.05 mm wide and 50 +/- 5 mm long. With these vascular dimensions the vascular conductance of the arcade (2.5 microliters/(s x mmHg] was calculated to be inadequate for the blood supply to the pregnant uterus at term. During the course of pregnancy modest changes were seen: The arcade increased 80% in length, 30% and 80% in internal diameter at the ovarian and cervical origin respectively and 6 times in conductance. Weight of the arcades increased 2-3-fold, [3H]thymidine incorporation rate 7-fold whereas the DNA mass remained constant. Ligation of the uterine artery on day 8 caused a 2 times increase in internal diameter of the ovarian (open) origin of the arcade without change in weight, whilst the cervical (ligated) origin of the arcade had the same internal diameter as that of the control group. The calculated vascular conductance of the ligated arcade was the same as for controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1988

The effects of the proliferation of the radial arteries of the placenta on oxygen transport to the fetal guinea pig.

The adjustment of placental blood flow during pregnancy is related to progressive structual changes in the placental arteries. In guinea pig, massive growth has also been shown to be associated with widening of the uterine radial arteries. The rate of 3H-thymidine incorporation into uterine radial arteries during pregnancy was studied in guinea pig as a measure of local DNA synthesis. And the oxygen partial pressure was used to investigate how the oxygen transport is done between mother to fetus. During the first half of pregnancy, 3H-thymidine was incorporated at the rate of about 1,000 Bq/mg.h. The initial rate during pregnancy is similar to the rate observed during estrus. This observation suggest that the same factors stimulate DNA synthesis during gestation and estrus. The rate of 3H-thymidine incorporation per vessel length increased with the injected dose of estradiol benzoate. We suppose that estradiol is one of the control factors in DNA synthesis in uterine radial artery. The oxygen partial pressure in amniotic fluid was about 110 mmHg on various days of gestation and no significant changes were observed with time. For these reasons, estrogen is supposed to be one of the control factors in oxygen transport to fetus.

Amniotic Fluid↗

PubMed1985

Effects of the lipidperoxidation product 4-hydroxynonenal and related aldehydes on proliferation and viability of cultured Ehrlich ascites tumor cells.

The mechanism by which the lipid peroxidation product 4-hydroxynonenal and several other homologous, yet non biogenic aldehydes inhibit proliferation of cultured Ehrlich ascites tumor cells has been studied. Incubation of cells (5 X 10(-4)/ml) in a minimum essential medium supplemented with 10 or 20 microM 4-hydroxynonenal reduces the 36-hr cell count to 65 and 30% of the control value. The reduced growth rate is most likely due to a blockage of the DNA synthesis. Cells labelled by a [3H]-thymidine pulse prior to exposure to 4-hydroxynonenal (20 microM, 8 hr) showed no change of the specific radioactivity of the DNA, indicating that no de novo synthesis occurred in the presence of the aldehyde. In the absence of the aldehyde the specific radioactivity of the DNA decreased by 25%. A 2-hr incubation in the presence of 10 or 20 microM of 4-hydroxynonenal reduced [3H]-thymidine incorporation into the HClO4 insoluble fraction to 85 and 50% of the controls, but had no effect of the [3H]-thymidine and 86Rb uptake. Moreover, examination of the cell cultures by the Trypan Blue exclusion technique revealed that 20 microM 4-hydroxynonenal does not cause cell death. The high reactivity of 4-hydroxynonenal towards sulfhydryl groups suggests that the aldehyde inhibits DNA synthesis by interacting with a functional SH group of DNA polymerase. The specific action on DNA synthesis is abolished at an aldehyde concentration of 50 microM, which leads to 30% (6 hr exposure) and 95% (36 hr exposure) of dead cells. The cytostatic index (CI), i.e. concentration at 50% Trypan Blue positive cells/concentration at 50% inhibition of cell growth deducted from the dose effect curves is 3.0 for 4-hydroxynonenal. The other homologous 4-hydroxyalkenals with chain length of 5, 6, 7, 8, 10 and 11 carbon atoms also inhibit cell growth. The CI varied from 1.20 to 1.94, indicating that these non biogenic 4-hydroxyalkenals have a distinctively lower specific effect on proliferation than the biogenic 4-hydroxynonenal. The Michael adducts of 4-hydroxynonenal with glutathione and cysteine were nearly one order of magnitude less toxic than the free aldehyde, the CI (2.41 cysteine adduct, 2.06 glutathione adduct), however, were not improved since the growth inhibitory action was also reduced.

Aldehydes↗

PubMed1985

Pressure-diameter curves of mesometrial arteries of guinea pigs demonstrate a non-muscular, oestrogen-inducible mechanism of lumen regulation.

Pressure-diameter curves were determined on mesometrial (uterine radial) arteries obtained from guinea pigs during different stages of ovarian cycle and pregnancy. In order to investigate changes in arterial diameter that are not caused by the vascular musculature, we studied excised arteries that were relaxed by papaverine (40 mg/l). The pressure-diameter curves were found to be shifted toward wider diameters when the arteries studied were obtained from pregnant, oestrous or oestrogen treated animals (oestradiol benzoate, 10 micrograms s.c.): the external diameter at 60 mm Hg transmural pressure on the 14th day of pregnancy exceeded the one during dioestrus by 50%. At term, there was a 7-fold increase. During oestrus and 24 h after oestrogen treatment the diameter was 30-40% wider than during dioestrus. Moreover, we found that the diameter measured on excised vessels in the presence of papaverine is the same as the one observed in situ. We conclude that the mesometrial arteries of guinea pigs possess a muscle-independent mechanism of lumen regulation. The mechanism operates in non-pregnant and pregnant animals. It may be induced by oestrogen and seems to be qualified for long-term lumen regulation during pregnancy. In contrast, dilation by smooth muscle relaxation appears to be of minor importance in mesometrial arteries.

Animals↗

PubMed1984

Drastic rise of intracellular adenosine(5')tetraphospho(5')adenosine correlates with onset of DNA synthesis in eukaryotic cells.

An assay of adenosine(5')tetraphospho(5')adenosine (Ap4A), based on the luciferin/luciferase method for ATP measurement, was developed, which allows one to determine picomolar amounts of unlabeled Ap4A in cellular extracts. In eukaryotic cells this method yielded levels of Ap4A varying from 0.01 microM to 13 microM depending on the growth, cell cycle, transformation, and differentiation state of cells. After mitogenic stimulation of G1-arrested mouse 3T3 and baby hamster kidney fibroblasts the Ap4A pools gradually increased 1000-fold during progression through the G1 phase reaching maximum Ap4A concentrations of about 10 microM in the S phase. Quiescent 3T3 cells reach a high level of Ap4A (1 microM) in a 'committed' but prereplicative state if exposed to an external mitogenic stimulant (excess of serum) and simultaneously to a synchronizer which inhibits entry into the S phase (hydroxyurea). When the block for DNA replication was removed at varying times after removal of the stimulant decay of commitment to DNA synthesis was found correlated with a shrinkage of the Ap4A pool. Cells lacking a defined G1 phase (V79 lung fibroblasts, Physarum) possess a constitutively high base level of Ap4A (about 0.3 microM) even during mitosis. From this high level, Ap4A concentration increases only about tenfold during the S phase. Temperature-down-shift experiments, using chick embryo cells infected with transformation-defective temperature-sensitive viral mutants(td-ts), have shown that the expression of the transformed state at 35 degrees C is accompanied by a tenfold increase of the cellular Ap4A pool. Treatment of exponentially growing human cells with interferon leads, concomitantly with an inhibition of DNA syntheses, to a tenfold decrease in intracellular Ap4A levels within 20 h. The possibility of Ap4A being a 'second messenger' of cell cycle and proliferation control is discussed in the light of these results and those reported previously demonstrating that Ap4A is a ligand of mammalian DNA polymerase alpha, triggers DNA replication in quiescent mammalian cells and is active in priming DNA synthesis.

Adenine Nucleotides↗

PubMed1984

Problems and pitfalls in estimating average pharmacokinetic parameters.

The problems of obtaining optimal average parameter estimates (APE) from experimental pharmacokinetic data are considered. Four different approaches, three parametric and one non-parametric tests, are compared, using selected individual alcohol concentration data. Pooling the raw data for estimating APE can obscure individual pharmacokinetic characteristics, whereas averaging individual parameter estimates (IPE) exposes unique statistical problems. Furthermore, careful consideration should be given to weighting procedures. The advantages and shortcomings of all four methods are discussed. It is concluded that none can be considered as a universally applicable statistical method in view of the purpose for which the information, derived from a set of data, e.g. an alcohol-kinetic study, is required.

Computers↗

PubMed1984

The pharmacokinetics of alcohol in human breath, venous and arterial blood after oral ingestion.

The concentration-time profile of ethanol in breath air (AAC), arterial (ABAC) and venous blood (VBAC) of human volunteers was studied after four different oral doses of absolute alcohol--0.5, 0.75, 1.0, and 1.25 g/kg body weight. Seventy-eight single dose experiments were carried out in 42 subjects. In all 78 studies AAC was measured and VBAC was estimated simultaneously in blood collected from a cubital vein of 36 volunteers. Arterial blood, too, was collected from 8 subjects from a catheter in a brachial artery. All blood alcohol concentrations were analysed independently by gas chromatography (GLC) and an enzymatic (ADH) method. A one-compartment open model with first order absorption and pseudo-zero-order elimination was employed to calculate the pharmacokinetic parameters. The average values for the first order absorption rate constant (ka) ranged from 2.2 to 3.1, from 2.4 to 2.6 and from 1.0 to 1.7 h-1 for ACC, ABAC and VBAC, respectively. The pseudo-zero-order elimination rate constant (beta) was 0.17 to 0.18, 0.21 to 0.22 and 0.26 to 0.27 g X 1(-1) X h-1, respectively. During absorption ABAC tended to be higher than VBAC, peaking at a higher level (Cmax) and with a shorter time to peak (tmax) until an arterio-venous concentration equilibrium was reached, whereafter VBAC remained above ABAC. Although there was a close relationship between AAC, ABAC and VBAC during elimination, AAC closely followed the pattern of ABAC during absorption and tended to deviate from VBAC. AAC, therefore, is a much better predictor of ABAC during absorption than VBAC.

Absorption↗

PubMed1984

Evidence for rotational contribution to protein-facilitated proton transport.

Two modes of molecular motion of carrier molecules can, in principle, lead to a facilitated transport of a substrate: translational and rotational diffusion. In the present study, which deals with the mechanism of the facilitated diffusion of H+ and O2 in solutions of earthworm hemoglobin, examples for both types of facilitation are presented. Only translational, not rotational, diffusion of earthworm hemoglobin appears to lead to a facilitated O2 flux. In contrast, substantial facilitated H+ fluxes of comparable size arise from rotational diffusion as well as from translational diffusion of this large protein. This is derived from measurements of facilitated H+ and O2 fluxes in earthworm hemoglobin solutions and determinations of the rotational and translational diffusion coefficients of earthworm hemoglobin with the help of a theoretical treatment of facilitated diffusion by rotational carrier diffusion. H+ transport by rotational protein diffusion appears to be a case where the often-postulated mechanism of facilitated transport by rotation of a carrier lends itself to experimental verification.

Biological Transport↗

PubMed1983

Blood circulation and oxygen transport in the fetal guinea pig.

Anaesthetized fetal guinea pigs near term were studied under conditions, where maternal placental flow of haemoglobin was maintained within the normal range. The rate of maternal fetal equilibration of intravenously injected 3H2O was found to be similar as in unanaesthetized animals (half time 4 min) indicating that fetal circulation was undisturbed under the present experimental conditions. Umbilical blood flow as determined by a modified 3H2O method was 0.13 ml . min-1 . g-1 of fetal body mass. Radioactive microspheres, injected into the fetal saphenous (jugular) vein, were distributed to the placenta, the lower body, the upper body and the lungs at a ratio of 31(47):27(39):30(6):12(8). From these data, cardiac output was calculated (0.38 ml . min-1 . g-1) and found to be almost equally distributed between the placenta, the lower body and the upper body. There was preferential streaming of the inferior vena caval blood to the upper body. There was no evidence for flow through a ductus venosus. The O2-saturation in the fetal carotid arterial blood was 59 +/- 4%. The O2-supply to the fetal tissues was estimated to be 3 times the oxygen consumption.

Animals↗

PubMed1981

High oxygen affinity of maternal blood reduces fetal weight in rats.

In order to obtain information on the physiological significance of the difference in oxygen affinity between maternal and fetal blood, we have examined the effect of an acute increase of the oxygen affinity of maternal blood in pregnant rats, on fetal body weight, fetal brain and liver weights, placental weight, and the hematocrit of fetal blood. The increase in oxygen affinity was produced by exchange-transfusing pregnant rats on day 19 of gestation with blood that had been treated previously with sodium cyanate. As a result of the exchange transfusion, the difference in oxygen affinity between maternal and fetal blood essentially disappeared. Pregnant rats exchanged with normal blood served as controls. On day 21 of gestation, the fetal body weight and the fetal liver weight were significantly smaller by 18% and 25% respectively, in the group where the oxygen affinity of the maternal blood was acutely raised when compared to the controls. Also, the hematocrit of the fetal blood was significantly higher in the group where mothers had the high blood oxygen affinity. Placental weight and fetal brain weight were not significantly altered. We infer, that the reduction of fetal weight is due to fetal hypoxia which is caused by the abolishment of the difference in oxygen affinity between maternal and fetal blood. Human infants, whose birth weight is too small for their gestational age have a significantly increased postnatal mortality compared to babies with normal weight. We suppose that the increased mortality of newborns who are too small for their gestational age, represents a selective pressure that has favoured the evolution of a high oxygen affinity of fetal in comparison with maternal blood.

Animals↗

PubMed1980

Facilitated diffusion of lactic acid in the guinea-pig placenta.

In the guinea-pig placenta which was artificially perfused on the fetal side while maternal placental blood flow was controlled, the placental transfer per mean transplacental concentration difference (the transfer coefficient TC) was determined for lactate. TC for L-lactate (TCLL) was compared to that for D-lactate (TCDL) and measured for various concentrations of L-lactate, bicarbonate, pyruvate and CO2. Applying a "closed circuit" perfusion technique, L-lactate and proton concentrations on both sides of the placenta were followed during infusion of HCl and sodium L-lactate into the fetal circulation. It was found that TCLL is 3 times TCDL. TCLL is depressed by increasing concentrations of L-lactate while TC for Cl-36 is not. TCLL is also depressed by 50 mmol.1-1 pyruvate. Concentration changes of glucose do not affect TCLL. TCLL rises with the proton concentration, independently of the concomitant changes of the bicarbonate concentration. Transplacental proton concentration gradients produce L-lactate concentration gradients and vice versa. It is concluded that (1) facilitated diffusion of L-lactate occurs in the placenta and that (2) L-lactate transfer is coupled with proton transfer. Beside the well-known placental transport system for glucose this is the second passive transport system found in a placenta.

Animals↗

PubMed1978

The flow resistance of the spiral artery and the related intervillous space in the rhesus monkey placenta.

Uteroplacental arteries of 4 rhesus monkeys were cannulated at their myometrical portions and perfused with dextran solutions and blood. Pressure-flow curves were obtained for the spiral artery and the related intervillous space, i.e. for the functional cotyledonary unit of the haemochorial villous placenta. For a flow of 3 ml.min-1, which is probably the normal rate of flow through the spiral artery, the pressure at the entry of the spiral artery was found to be 13--18 mm Hg (1.7--2.4kPa) during uterine relaxation (uterine diastole). There was a direct proportional relationship between the spiral artery flow and the pressure difference between the spiral artery and the amniotic fluid; the pressure difference per flow (the resistance of the cotyledonary unit) was found to be 1--3 mm Hg . ml-1 . min (8--24kPa . ml-1 . s). It is concluded that the spiral artery and the related intervillous space do not offer a limiting resistance to maternal blood flow in the absence of uterine contractions.

Animals↗