Total folate binding capacity of normal human plasma, and variations in uremia, cirrhosis, and pregnancy.

The current study presents evidence that all human serum contains a class of high-affinity folate binders (KA=2.8 X10(10 liters/mole), which migrate as a single peak on gel filtration. Failure of previous studies to detect this characteristic in all but a minority of subjects is attributable to its variable, often total, saturation. Direct measurement of the total folate binding capacity (TFBC) has been made possible by dissociation of endogenous folate-binder complexes at acid pH, removal of free folate by coated charcoal, and radiofolate tagging. This procedure does not appear to significantly denature the binders, which release and rebind similar quantities of 3H-PGA. In 20 normal subjects, TFBC ranged from 100 to 325 pg/ml (mean+/-SE = 174+/-16), and was always at least 33% saturated. In three clinical conditions, all associated with elevated unsaturated folate binding capacity, three different patterns emerged when TFBC was also measured. Uremic subjects had significantly elevated mean TFBC with normal saturation. In cirrhotic subjects, mean TFBC approximated normal, but saturation was significantly decreased. In pregnancy, two groups were seen: one with increased TFBC and the other with a normal TFBC, some of whom had decreased saturation. Lactobacillus casei serum folate level was about 30 times greater than the TFBC; there was no correlation between the two measurements.     

The newly developed method of 19-OH-A as intermediate of estrone biosynthesis by GC-MS

To study the serum levels of 19-hydroxyandrostenedione (19-OH-A), known as an obligatory intermediate of estrogen biosynthesis and considered to be one of the hypertensinogens, a method using GC-MS with application of synthesized [7,7-d2]androstenedione (A), [7,7-d2] 19-OH-A and [9,11-d2]estrone(E1) as internal standards was newly developed. Normal pregnant women and pregnant women complicated with hypertension near term were selected for the study. The levels of 19-OH-A and E1 increased significantly as gestation progressed [19-OH-A; 224.7 +/- 72.1 (1st trimester), 655.5 +/- 325.4 (2nd trimester). 1517.8 +/- 543.6 (3rd trimester)pg/ml], and a positive correlation was found between the levels of the two steroids. No apparent change was observed in A levels during the course of pregnancy. The mean levels of 19-OH-A in pregnancy complicated with hypertension at 2nd and 3rd trimester were 761.7 +/- 348.9 and 1473.0 +/- 491.4 pg/ml, which were compatible with those in normal pregnancy. The levels of 19-OH-A at delivery in maternal vein (MV) were 1735.1 +/- 683.9 pg/ml. Significantly higher levels of 19-OH-A were found in umbilical vein (UV) (1977.2 +/- 564.9 pg/ml) than those in umbilical artery (109.7 +/- 49.1 pg/ml). 19-OH-A concentration in term placental tissue was 16.3 ng/g.w.w. tissue. This is the first report to demonstrate the serum 19-OH-A levels measured by GC-MS and also to demonstrate the levels in the cord blood. The results indicate that 19-OH-A may be the product of pregnancy and may be derived from the feto-placental compartment.     

Circulating immunoreactive somatostatin in man. Effect of age, pregnancy, growth hormone deficiency and achlorhydria

Plasma immunoreactive somatostatin (IRS) levels were measured fasting at 09.00 h in groups of adult individuals and children of different ages, as well as in pregnant women, in patients with pernicious anaemia documented to be achlorhydric, and in children with growth hormone deficiency. There was a gradual rise in the mean level of IRS from the third decade (mean 35.8 +/- 3.8 pg/ml), which reached significance at the seventh (61.1 +/- 8.4 pg/ml), eighth (66.7 +/- 5 pg/ml) and ninth decade (82.6 +/- 13.8 pg/ml). No change was observed in the second 28.3 +/- 3.8 pg/ml) and third (31.1 +/- 3.2 pg/ml) trimester of pregnancy when compared with matched, non-pregnant controls (29.7 +/- 2.2 pg/ml); however, the children aged under 2 years (69.6 +/- 11.2 pg/ml) had significantly higher values than the eldest group (12 to 16 years old) (46.3 +/- 7.2 pg/ml) (P less than 0.05). In achlorhydric patients, basal (27.2 +/- 3.7 pg/ml; P less than 0.01) and postprandial IRS (42.8 +/- 7.7 pg/ml; P less than 0.001) was significantly lower than in a matched, normal control group (basal 59.4 +/- 7.2; postprandial 132.1 +/- 26.3 pg/ml). Growth hormone deficiency was not associated with any differences in circulating IRS, basally or after insulin hypoglycaemia, when compared with values in normal children.(ABSTRACT TRUNCATED AT 250 WORDS)     

Immunoreactive corticotropin-releasing hormone in human plasma during pregnancy, labor, and delivery

We previously reported that immunoreactive corticotropin-releasing hormone (CRH) is present in human placenta and third trimester maternal plasma, and that such material is very similar to rat CRH and the predicted structure of human CRH. We suggested that maternal plasma immunoreactive CRH may be of placental origin. To further investigate this possibility, we measured plasma immunoreactive CRH in women during pregnancy, labor, and delivery and 1 and 2 h postpartum, and in nonpregnant women. Umbilical cord plasma and placental CRH concentrations were also measured. In the first trimester of pregnancy, the mean maternal plasma level was 5.9 +/- 1.0 pg (+/- SEM)/ml (n = 24), not significantly different from that in 10 nonpregnant women (5.8 +/- 0.8 pg/ml). Plasma CRH concentrations progressively increased during pregnancy (second trimester, 35.4 +/- 5.9 pg/ml (n = 39); early third trimester (28-34 weeks), 263 +/- 41 pg/ml (n = 14); late third trimester (35-40 weeks), 800 +/- 163 pg/ml (n = 20)]. There was a significant correlation between maternal plasma CRH levels and weeks of pregnancy. Plasma CRH concentrations were further elevated (2215 +/- 329 pg/ml; n = 9). During early labor, peaked at delivery (4409 +/- 591 pg/ml; n = 28), and declined rapidly after delivery [1 h postpartum, 1042 +/- (353 pg/ml (n = 13); 2 h postpartum, 346 +/- 91 pg/ml (n = 13)]. There was a significant correlation (r = 0.562; P less than 0.01) between matched maternal plasma and placental CRH concentrations. The mean umbilical cord plasma CRH level (50.6 +/- 6.1 pg/ml; n = 28) was much lower than that in the mother at the time of delivery. Umbilical venous plasma CRH levels were significantly greater than those in simultaneously obtained umbilical arterial plasma (70.8 +/- 11.3 and 41.8 +/- 4.9 pg/ml, respectively; n = 11). There was a significant correlation (r = 0.384; P less than 0.05) between maternal and fetal CRH concentrations. Gel filtration of plasma obtained from women during the third trimester, at delivery, and early postpartum and placental extracts revealed two major peaks of immunoreactive CRH: a high mol wt peak and one at the elution position of rat CRH. In contrast, only rat CRH-sized material was detected in plasma from nonpregnant women and umbilical cord plasma. Maternal plasma immunoreactive CRH-sized material stimulated ACTH release from anterior pituitary tissue in a dose-dependent manner and was equipotent with rat CRH.(ABSTRACT TRUNCATED AT 400 WORDS)     

Immunoreactive corticotropin-releasing factor is present in human maternal plasma during the third trimester of pregnancy

Immunoreactive (IR) corticotropin-releasing factor (CRF)-like activity was detectable in the majority of plasma samples obtained from women in the third trimester of pregnancy (68.7 +/- 23.6 pg/ml (14.4 +/- 4.9 fmol/ml); mean +/- SE, n = 15), but not in plasma (less than 10 pg/ml) from first (n = 9) or second (n = 11) trimester of pregnancy, 1 day post partum (n = 7), non-pregnant women (n = 10), or in plasma obtained from patients with Cushing's disease (n = 2) or Nelson's syndrome (n = 1), or in basal (n = 6) or ether-stressed (n = 6) rat plasma. Gel filtration of third trimester pooled plasma revealed that the majority of such material eluted with Kav of rat CRF (1-41). The IR CRF (1-41)-sized material eluted with the identical retention time as rat CRF in a reverse phase high performance liquid chromatography (HPLC) system. The detection of IR CRF exclusively in third trimester maternal plasma, together with our previous demonstration that material physicochemically indistinguishable from it is present in human term placental extracts, suggests that the placenta may be the source of plasma IR CRF.     

First trimester placental growth factor and soluble fms-like tyrosine kinase 1 and risk for preeclampsia

An imbalance of pro- and antiangiogenic factors may lead to preeclampsia (PE). In this prospective nested case-control study, we investigated whether first trimester serum levels of placental growth factor (PlGF), a potent angiogenic factor, and its soluble inhibitor, soluble fms-like tyrosine kinase 1 (sFlt1), distinguished women who developed PE (n = 40) from those who developed gestational hypertension (n = 40), delivered a small for gestational age (SGA) newborn (n = 40), or completed a full term normal pregnancy (n = 80). Compared with controls, serum PlGF levels were lower among women who developed PE (23 +/- 24 pg/ml vs. 63 +/- 145 pg/ml; P < 0.01) or gestational hypertension (27 +/- 19 pg/ml; P = 0.03), or who delivered a SGA newborn (21 +/- 16 pg/ml; P < 0.01). In contrast, serum sFlt1 levels did not markedly differ between the groups: PE, 1048 +/- 657 pg/ml; gestational hypertension, 942 +/- 437 pg/ml; SGA newborns, 1011 +/- 479 pg/ml; and normal controls, 973 +/- 490 pg/ml. Multivariable analysis adjusting for potential confounders and serum sFlt1 levels demonstrated a 3.7-fold (95% confidence interval, 1.2-12.5) increase in risk for PE for every log unit decrease in serum levels of PlGF compared with controls. Analyses for gestational hypertension and SGA were not significant. Examined in tertiles, the risk for PE was increased 28.7-fold (95% confidence interval, 2.3-351.0) in the third (<12 pg/ml) compared with the first (>39 pg/ml) PlGF tertile. First trimester serum levels of PlGF and sFlt1 may identify women at high risk for PE.     

Endogenous digoxin-immunoreactive substance in human pregnancies

We report the presence of an immunoreactive digoxin-like substance in blood from third trimester pregnant women. The sera from 51 women in the third trimester of pregnancy were analyzed by 4 commercially available digoxin RIAs. None of these patients was receiving digoxin. Digoxin immunoreactivity was detected in all patients by 3 of 4 assays. The measured values, in nanograms per ml digoxin equivalent, were (mean +/- SD): method A, 0.27 +/- 0.05; method B, 0.28 +/- 0.07; method C, 0.01 +/- 0.01; and method D, 0.15 +/- 0.06. Method B measured values greater than 0.50 ng/ml in sera from 5 patients. Digoxin immunoactivity was not detectable 24 h postpartum, suggesting a half-life in serum of 6 h or less. Exogenous digoxin added to these serum samples resulted in quantitatively additive increments above the endogenous measured levels. Three of 4 digoxin RIAs did not distinguish between true digoxin and the endogenous substance present in the sera of third-trimester pregnant patients. Preliminary evidence suggests that the endogenous digoxin immunoactivity is not due to elevation of levels of major known steroids in the blood of these women. Clinical management of women requiring digoxin therapy during pregnancy, therefore, is complicated by the inability to assume the same therapeutic range of digoxin in serum during the third trimester of pregnancy as in adult nonpregnant individuals.     

A specific radioimmunoassay for 5''-deoxyadenosyl cobalamin in serum

A specific radioimmunoassay for 5'-deoxyadenosyl cobalamin (ado-Cbl) has been developed using an antiserum raised to this cobalamin (Cbl). At a 1:100 or greater dilution the antiserum did not bind radiolabelled methyl-, hydroxo-, sulphito- or cyano-Cbl and these Cbl analogues did not compete in the radioimmunoassay even at 100-fold higher concentration. The serum concentration (range and mean +/- SD) of ado-Cbl in 30 normal subjects was 47-134 and 81 +/- 16 pg/ml. The corresponding values for total Cbl in these sera were 189-610 and 355 +/- 144 pg/ml, and the computed values for methyl-Cbl were 142-476 and 274 +/- 127 pg/ml. The coefficient of variation was substantially greater for methyl-Cbl than for ado-Cbl (46% v. 21%, respectively). The ado-Cbl concentration was in the normal range (75-95 pg/ml) in five healthy subjects with a low normal concentration (189-217 pg/ml) of total Cbl. In two subjects with low total Cbl (118 and 170 pg/ml) and without any clinical evidence of Cbl deficiency, ado-Cbl was normal (63 and 95 pg/ml, respectively). Thus, in this group, low methyl-Cbl accounted for the lower total Cbl. The concentration (mean +/- SD) of serum ado-Cbl and methyl-Cbl in six patients with low total Cbl (57 +/- 25 pg/ml) and clinical evidence for Cbl deficiency was 35 +/- 12 pg/ml and 22 +/- 22 pg/ml, respectively. This difference from the normal mean for each cofactor was highly significant (P less than 0.001). The decrease in the concentration of methyl-Cbl in Cbl deficiency was relatively greater than the decrease in ado-Cbl (92% v. 57%, respectively) which raised the relative concentration of ado-Cbl in Cbl deficiency to 61% of the total Cbl. Although a low serum methyl-Cbl is a sensitive indicator of Cbl deficiency, it may not be as specific as a decrease in serum ado-Cbl. Factor(s) other than tissue stores of Cbl may lower serum methyl-Cbl below the 95% confidence limit in the absence of clinical Cbl deficiency.     

Secretory leukocyte protease inhibitor concentration increases in amniotic fluid with the onset of labour in women: characterization of sites of release within the uterus.

Secretory leukocyte protease inhibitor is a potent inhibitor of neutrophil function, a mediator of mucosal immunity and an inhibitor of NF|gkB regulated inflammatory responses. However, its source, function and regulation within the uterus during pregnancy and at parturition are not well defined. In amniotic fluid, the concentration of secretory leukocyte protease inhibitor increased significantly from 2nd trimester (24+/-3 ng/ml; mean+/-s.e.m.; n=20) to term (751+/-53 ng/ml; P<0.05; n=15) with a further profound increase (P<0.005) with the onset of labour (3929+/-1076 ng/ml; n=15). To establish the intra-uterine sites of secretion, explants (n=6 different patients per tissue) were collected at term after elective caesarean section. High levels of secretory leukocyte protease inhibitor were released by decidua (135.2+/-12.4 pg/mg; mean+/-s.e.m.) and chorio-decidua (325.1+/-26.4 pg/mg) with less by amnion (55.6+/-6.0 pg/mg) and placenta (9.2+/-1.9 pg/mg). Intense immunoreactivity for secretory leukocyte protease inhibitor was detected predominantly in decidua parietalis cells adherent to the chorion laeve and myometrium, and also in decidua basalis. We propose that, within the pregnant uterus, secretory leukocyte protease inhibitor is released by decidua, fetal membranes and potentially the fetal lung. The increase in secretory leukocyte protease inhibitor may act to modulate pro-inflammatory paracrine interactions for the maintenance of pregnancy and limit those occurring at parturition within the uterus.     

Comparison of circulating colony-forming cells in chronic granulocytic leukemia and leukemoid reaction

In vitro culture studies of peripheral blood leukocytes using semi-solid media from 8 patients with chronic granulocytic leukemia (CGL) and 5 patients with granulocytic leukemoid reaction were performed. A markedly increased number of circulating colony-forming units were present in patients with CGL (mean 343 +/- 47) as opposed to those having granulocytic leukemoid reaction (mean 7.0 +/- 4). The colony size was larger in CGL than in granulocytic leukemoid reaction or in normal peripheral blood.     

Serum concentrations of delta 5C21 steroids during pregnancy and at delivery

In order to study the changes of C21-steroid levels which included Pregnenolone (P5), 20 alpha dihydropregnenolone (20P5), 16 alpha hydroxypregnenolone (16P5), progesterone (P4) and 20 alpha dihydroprogesterone (20P4) in maternal peripheral blood during pregnancy and at delivery, these steroids were measured by GC-MASS with application of deuterated steroids as internal standard. The accuracy of GC-MASS method of these steroids was satisfactory with C.V. value of less than 6%. Total delta 5C21 steroid concentrations in course of pregnancy and at delivery were as follows; P5 (mean +/- S.D. ng/ml): 66.6 +/- 36.2 (1st trimester), 80.9 +/- 24.6 (2nd trimester), 147.7 +/- 30.1 (3rd trimester) and 299.7 +/- 178.3 ng/ml (at delivery), 20Ps: 212.6 +/- 102.5, 143.4 +/- 53.9, 248.9 +/- 58.8, 563.4 +/- 198.2 ng/ml, 16P5: 8.6 +/- 8.6, 8.1 +/- 5.2, 124.3 +/- 40.3, 378.5 +/- 180.0 ng/ml, respectively. P4 (43.0 +/- 28.0 ng/ml) and 20P4 (8.0 +/- 4.0 ng/ml) in 1st trimester showed gradual increase to maximum level (P4: 138.2 +/- 30.1 ng/ml, 20P4: 105.4 +/- 21.6 ng/ml) at pre-pain period, afterward decreased rapidly (P4: 70.9 +/- 23.2 ng/ml, 20P4: 59.8 +/- 19.3 ng/ml) at delivery. P5, 20P5 and 16P5 levels were found to be significantly higher in umbilical artery (UA) as well as in umbilical vein (UV) than those in maternal vein (MV) regardless of labor pain. P4 and 20P4 did not show any differences in MV regardless of labor pain. P4 in UV (pain+) and 20P4 in UA (pain-), however, showed significantly higher than P4 in UV (pain-) and 20P4 in UA (pain+). P5, 20P5, 16P5 and 20P4 levels were significantly lower in the case of anencephalic pregnancy (ANC) at 3rd trimester than in normal pregnancy, especially 16P5 levels (22.2 +/- 5.0 ng/ml) showed 1/5 of those in normal pregnancy. From the results obtained above, it is suggested that these delta 5C21 steroids are actively produced in the feto-placental unit in the course of pregnancy. The levels of these steroids reached maximum at delivery, but the levels of P4, 20P4 decreased toward delivery after maximum levels were shown in the stage of pre-labor pain. No significant difference of P4 level in the case of ANC suggested that P4 production correlated with placenta as well as maternal and fetal precursor. Decreasing of 20P4 and P4 level after the stage of pre-labor pain suggested that activity of 3 beta hydroxysteroid dehydrogenase was reflected by uterine contraction during labor.     

The responses of plasma adrenocorticotropin and cortisol to corticotropin-releasing hormone (CRH) and cerebrospinal fluid immunoreactive CRH in anorexia nervosa patients

Pituitary-adrenocortical responses to the iv injection of 100 micrograms synthetic ovine corticotropin-releasing hormone (CRH) were studied in 13 patients with anorexia nervosa, and the concentrations of immunoreactive CRH in cerebrospinal fluid were measured in 7 of them. Mean basal levels of plasma ACTH and cortisol were 32 +/- 5 pg/ml (+/- SEM) and 21.1 +/- 1.5 micrograms/dl, respectively. The latter value was significantly higher than that in age-matched normal women (P less than 0.005). The mean increments of plasma ACTH and cortisol in response to CRH injection in those 13 patients were 21 +/- 5 pg/ml and 5.3 +/- 1.7 micrograms/dl, respectively, significantly lower than those in normal women (58 +/- 6 pg/ml and 15.3 +/- 7.7 micrograms/dl, respectively; P less than 0.005). When 4 patients were reexamined after weight gains of between 3 and 22 kg, their responses to the CRH injection increased. The mean concentration of immunoreactive CRH in the cerebrospinal fluid of seven patients was 30.8 +/- 3.9 pg/ml (+/- SEM), which was higher than the value of 18.4 +/- 1.1 pg/ml (P less than 0.005) in control subjects with cervical spondylosis. These findings suggest the possibility that hypersecretion of CRH may occur in patients with anorexia nervosa.     

Longitudinal Changes in the B‐Type Natriuretic Peptide Levels in Normal Pregnancy and Postpartum

Normal levels of B‐type natriuretic peptide (BNP) are not well established in pregnancy. We obtained longitudinal BNP levels in 29 healthy pregnant women in each trimester and postpartum period, and compared these levels to the 25 nonpregnant controls. There were no significant differences among the cases and controls with respect to weight, diastolic blood pressure, and ethnicity. A total of 116 BNP values were obtained during pregnancy. The median (and range) BNP level during pregnancy was 19 (10–143) pg/ml versus 10 (10–37) pg/ml in the nonpregnant controls (p = 0.003). However, there were no statistically significant differences in the median BNP levels at various stages of pregnancy: first trimester 20 (10–115) pg/ml versus the second trimester 18 (10–112) pg/ml (p = 0.8), second trimester 18 pg/ml versus third trimester 26 (10–143) pg/ml (p = 0.06), and third trimester 26 pg/ml versus postpartum18 (10–62) pg/ml (p = 0.08). There were no significant differences between the BNP levels throughout the trimesters and postpartum period. Pregnant BNP levels were approximately twice as high as the nonpregnant BNP levels. Our study is unique in evaluating longitudinal changes in BNP levels in normal pregnancies and the postpartum period in comparison with healthy, nonpregnant controls. It demonstrates that pregnant BNP levels are approximately 2‐fold higher than their nonpregnant counterparts, and do not significantly fluctuate during pregnancy. In conclusion, pregnancy is associated with a significant, but small increase in the BNP levels compared with nonpregnant women. Copyright © 2009 Wiley Periodicals, Inc.     

The functional `G' cell mass in atrophic gastritis

The serum gastrin response to a standard protein meal has been determined in achlorhydric patients with atrophic gastritis and contrasted with the response in normal subjects whose gastric contents were kept continuously neutral by intragastric bicarbonate instillation.Five normal subjects showed a significant increase in serum gastrin from a mean (+/- SEM) of 17 +/- 3 pg/ml to 119 +/- 10 pg/ml but their response did not approach that of four patients with atrophic gastritis and antral sparing (605 +/- 133 pg/ml to 1418 +/- 186 pg/ml). By contrast, in four patients with antral gastritis, there was no significant change in gastrin levels (24 +/- 13 pg/ml to 55 +/- 19 pg/ml).These studies indicate that the gastrin-secreting cell mass is increased in atrophic gastritis with antral sparing and decreased in atrophic gastritis with antral involvement, as compared to the normal state. They provide further evidence for the existence in man of two distinct forms of atrophic gastritis.     

Cerebrospinal fluid tau protein levels in demented and nondemented alcoholics

The tau protein levels in cerebrospinal fluid (CSF-tau) were examined in 27 patients with alcohol dependence (20 demented and 7 nondemented), 36 age and dementia severity-matched patients with Alzheimer's disease (AD), and 23 age-matched normal control subjects. The CSF-tau levels in the demented alcoholic group (alcohol-induced organic brain disorders, 25.4 +/- 10.2 pg/ml) was significantly lower (p < 0.0001) than that in the AD group (96.1 +/- 53.3 pg/ml), but not significantly different from that in the nondemented alcoholics (18.1 +/- 10.2 pg/ml) or the controls (19.2 +/- 12.9 pg/ml). Using a 44.9 pg/ml as a cut-off value (mean + 2 SD of the normal control group), only one patient with alcohol-induced organic brain disorders exceeded the value, whereas 3 of 36 of the AD group showed CSF-tau levels less than this level. These findings suggest that alcohol-induced organic brain disorders are a group of dementias that are characterized by normal CSF-tau levels, and that the CSF examination for tau in combination with other clinical findings may help in differentiating alcohol-induced organic brain disorders from AD.     

Pregnancy as state of physiologic absorptive hypercalciuria

An increase in circulating, 1,25-dihydroxyvitamin D level and net intestinal calcium absorption have been previously demonstrated in pregnant women and have been widely regarded as compensatory mechanisms whereby fetal mineral demands are satisfied. The alternate possibility, that these adjustments might anticipate such demands, has not previously been considered. To examine the effects of pregnancy on the intestinal absorption and renal excretion of calcium, oral calcium tolerance tests were performed and urinary calcium excretion was measured in 16 healthy women receiving a moderate calcium intake during and after pregnancy. Circulating 1,25-dihydroxyvitamin D levels and indexes of parathyroid function were also measured. As expected, 1,25-dihydroxyvitamin D levels were significantly (p less than 0.05) elevated throughout pregnancy (94 +/- 11, 118 +/- 9, and 117 +/- 11 pg/ml in the first, second, and third trimesters, respectively, versus 51 +/- 5 pg/ml after delivery). Twenty-four-hour calcium excretion also increased sharply (247 +/- 54, 316 +/- 42, 300 +/- 61 mg versus 91 +/- 18 mg), often to the point of hypercalciuria. Calcium tolerance test results included significant increases in the calciuric and calcemic responses during each trimester, whereas fasting calcium excretion and parathyroid function remained normal. These findings portray normal pregnancy as a state of physiologic absorptive hypercalciuria and call into question the widespread practice of supplementing calcium intake in otherwise well-nourished women during pregnancy.     

Serum immunoreactive erythropoietin during pregnancy and in the early postpartum

We studied 209 women during normal pregnancy, at delivery, or in the early postpartum, to determine whether erythropoietin (EPO) response was appropriate for the degree of anaemia. Serum immunoreactive EPO was measured in 74 nonpregnant women, including 33 normal subjects (16.4 +/- 4.1 mU/ml) and 41 women with hypoplastic, haemolytic, dyserythropoietic, or iron-deficient anaemia. An inverse linear relationship (R = -0.88, P less than 0.0001) between log(EPO) and Hct was observed. Predicted EPO values were derived for each Hct and an O/P ratio of observed/predicted log(EPO) was calculated for each sample (1.00 +/- 0.10, range 0.80-1.20). Serum EPO levels (mU/ml) were significantly higher during pregnancy (30 +/- 16, n = 142), at delivery (31 +/- 16, n = 41), and on day 7 postpartum (37 +/- 35, n = 26) than in normal women (P less than 0.001). EPO levels increased steadily from 18 +/- 6 mU/ml in the first, to 26 +/- 14 mU/ml in the second, and to 35 +/- 18 mU/ml in the third trimester (P less than 0.0001). The O/P ratio was normal on day 7 postpartum (1.01 +/- 0.16), at delivery (1.03 +/- 0.16), and in the third trimester (0.96 +/- 0.15), but was significantly reduced in the first two trimesters (0.88 +/- 0.15, P less than 0.001). A significant negative correlation between log(EPO) and Hct was lacking in the first two trimesters, was present but with a reduced slope during the third trimester and at delivery, and was normal postpartum. We conclude that EPO response to anaemia is impaired in early pregnancy, recovers in late pregnancy, and normalizes rapidly in the postpartum.     

Serum transferrin receptor measurements in hematologic malignancies

An enzyme-linked immunosorbent assay using specific monoclonal antibodies was used to measure circulating transferrin receptor (TR) in 87 patients with various hematologic malignancies. The mean serum TR was significantly elevated in patients with myeloproliferative disorders (15.47 +/- 12.54 micrograms/ml), whereas there were no differences in chronic granulocytic leukemia (7.89 +/- 3.56 micrograms/ml), myelodysplastic disorders (9.25 +/- 4.73 micrograms/ml), and acute nonlymphocytic leukemia (3.85 +/- 3.50 micrograms/ml) as compared to normal (5.63 +/- 1.42 micrograms/ml). Among patients with lymphoproliferative disorders, the mean level was normal in lymphoma (5.73 +/- 2.59 micrograms/ml), multiple myeloma (5.47 +/- 1.31 micrograms/ml), and hairy cell leukemia (7.04 +/- 3.69 micrograms/ml). The serum TR was significantly elevated in chronic lymphocytic leukemia (CLL; 14.17 +/- 12.29 micrograms/ml), and the serum levels reflected the clinical stage of the disease. These findings suggest that serum TR measurement may provide a useful laboratory index of disease activity in certain disorders such as CLL, whereas it most likely reflects the intensity of erythropoiesis in the remaining hematological disorders that were evaluated in this study.     

Resistance to endogenous norepinephrine in Bartter's syndrome: reversion during indomethacin administration

In five patients with Bartter's syndrome, mean (+/-SE) plasma norepinephrine concentrations increased from 324 +/- 75 pg/ml with the patients in the supine position to 550 +/- 100 pg/ml, 753 +/- 104 pg/ml and 808 +/- 116 pg/ml after 2,5 and 10 minutes, respectively, in the standing position, levels significantly higher than normal. Plasma epinephrine concentrations were indistinguishable from normal. One patient was shown to resistant the pressor (but not the metabolic) effects of intravenously administered norepinephrine prior to treatment with reversion to normal pressor responsiveness during indomethacin administration. Similarly, that patient's exaggerated endogenous norepinephrine response to standing (10 minute plasma value of 1,110 pg/ml) reverted to normal (10 minute value of 462 pg/ml) during indomethacin administration. Thus, patients with Bartter's syndrome exhibit a hyperadrenergic state consisten with resistance to endogenous, as well as exogenous, norepinephrine. Since the metabolic responses to intravenously administered norepinephrine were normal in the patient studied, norepinephrine resistance would appear to be limited to the vasculare system. Reversion of norepinephrine resistance during administration of an inhibitor of prostaglandin synthesis suggests that this hyperadrenergic state is not a primary pathogenetic abnormality in Bartter's syndrome.     

Normal serum gastrin levels in patients with liver cirrhosis.

In 28 patients with cirrhosis of the liver, histologically confirmed by liver biopsy, serum gastrin concentrations were determined radioimmunologically afer an overnight fast. Mean value and standard deviation in the patients with cirrhosis (30.1 +/- 19.3 pg/ml) was not found to be significantly different from the mean value established in 275 normal subjects (39.7 +/- 21.3 pg/ml).