Surfactant protein A (SP-A) is decreased in acute parenchymal lung injury associated with polytrauma.

To further investigate if the pulmonary surfactant system is altered in acute parenchymal lung injury of adults following polytrauma we measured SP-A level and phospholipid composition in 150 sequentially obtained lung lavage samples from poly-traumatized patients (n = 19) beginning at the day of trauma and ending 18 days later or when the patient was extubated. Out of the 19 patients studied 10 had severe parenchymal lung injury (ARDS), nine had moderate lung injury. SP-A was measured using a two-monoclonal sandwich ELISA-assay. Phospholipids were separated using high-performance liquid chromatography and their composition was calculated by comparison with standard phospholipid mixtures. We found immunoreactive SP-A concentrations ranging from 0.1 micrograms ml-1 to 8.5 micrograms ml-1 lung lavage fluid obtained from all patients. The mean SP-A concentration in patients who had severe parenchymal lung injury (ARDS) was 1.06 +/- 0.16 micrograms ml-1 lavage fluid, the mean concentration in patients who had only moderate parenchymal lung injury was 1.92 +/- 0.18 micrograms ml-1 lavage fluid. Both concentrations were lower than in healthy controls (2.74 +/- 0.3 micrograms ml-1 lavage fluid; n = 12). In patients who had moderate lung injury the SP-A level normalized, but in patients who had severe lung injury the SP-A level remained low during the timespan examined. SP-A alterations did not correlate to changes in phospholipid composition as determined in lung lavage samples of individual patients. We conclude that alveolar SP-A concentrations decrease in polytraumatized patients who have acute parenchymal lung injury soon after the trauma occurs.(ABSTRACT TRUNCATED AT 250 WORDS)     

Amniotic fluid phospholipids and foetal lung maturation

An analysis was made of samples of amniotic fluid from 82 pregnant women with normal pregnancies, ranging from 29 to 40 weeks of amenorrhoea. Lipid extraction was quantitative and individual phospholipids were isolated by two-dimensional chromatography. The lecithin/sphingomyelin ratio (L/S) increased significantly (t = 2.17; p less than 0.05) between 35 and 36 weeks of amenorrhoea (from 2.9 +/- 1.0 to 4.3 +/- 1.7). Phosphatidyl-glycerol (PG) was detected from 35 weeks of pregnancy, the time at which the incidence of amniotic samples with mature surfactant (L/S greater than or equal to 2.7 and presence of PG) was 9%; mature surfactant incidence increased to 55.5% at 36 weeks and 100% at 37 or more weeks. There was a good correlation between surfactant levels in amniotic fluid and new-born respiratory function.     

Concanavalin A binding of alpha-fetoprotein in amniotic fluid as an aid in the diagnosis of neural tube defects

Concanavalin A nonreactive alpha-fetoprotein was determined in samples of amniotic fluid from 16 abnormal pregnancies complicated by anencephaly (7), open spina bifida (6), intra-uterine death (1), anencephaly with exomphalos (1), or open spina bifida with exomphalos (1), and in amniotic fluid from 50 normal pregnancies with gestational age between 13 and 24 weeks. In all 16 cases with fetal malformations, the proportion of nonreactive alpha-fetoprotein was significantly decreased (median 5.3%) as compared with amniotic fluid from pregnancies with a normal outcome (median 39.7%). The results confirm that this measurement is useful in the diagnosis of neural tube defects, especially when the concentration of alpha-fetoprotein in amniotic fluid is normal or only slightly above normal and gestational age is uncertain.     

Relationships among human amniotic fluid dipalmitoyl lecithin, postpartum respiratory compliance, and neonatal respiratory distress syndrome

The major molecular species of amniotic fluid phosphatidylcholine were determined as diacylglycerol trimethylsilyl ether derivatives by gas-liquid chromatography with use of glass capillary columns. We studied amniotic fluid specimens from 48 pregnancies. As expected, the major disaturated species of amniotic fluid phosphatidylcholine, dipalmitoylphosphatidylcholine, and palmitoylmyristoylphosphatidylcholine increased with gestational age, whereas phosphatidylcholine species with 34, 36, and 38 carbon atoms in the acyl radicals decreased. Although the amniotic fluid samples were obtained shortly before parturition (4.2 +/- 3.7 h, mean +/- SD), the correlation between dipalmitoylphosphatidylcholine concentration in amniotic fluid and gestational age was better than between dipalmitoylphosphatidylcholine concentration and the compliance of the respiratory system of the newborns. In addition, the percentage of amniotic fluid phosphatidylcholine species present as dipalmitoylphosphatidylcholine seemed to be a more reliable predictor of lung maturity than was the absolute dipalmitoylphosphatidylcholine concentration in amniotic fluid.     

Amniotic fluid laminin and type IV collagen in normal and pathological pregnancies

Specific radioimmunoassays for the fragment P1 of human laminin and the 7-S collagen domain of human type IV collagen were used to quantify these basement membrane proteins in second trimester amniotic fluid samples from 21 normal and 41 pathological pregnancies, the latter group being defined by elevated amniotic fluid alpha-foetoprotein (AFP) or abnormal foetal karyotype, or both. The mean laminin P1 concentration in the normal 15 to 18-wk pregnancies was 36 micrograms/l (range 10-77) and that of the 7-S collagen was 46 micrograms/l (range 7-152). The molecular size of the antigens in amniotic fluid from both normal and pathological pregnancies, when assessed by gel filtration was very large, probably representing intact laminin and type IV collagen. Pathological pregnancies, e.g. cases of Turner syndrome, Meckel syndrome and anencephaly often had elevated amniotic fluid laminin and type IV collagen concentrations. A weak, but nevertheless significant, correlation was found between the amniotic fluid laminin and type IV collagen concentrations and also between type IV collagen and AFP, but none between laminin and AFP. In eight pregnancies with foetuses suffering from the congenital nephrotic syndrome of the Finnish type, a genetic disease assumed primarily to involve some component of the glomerular basement membrane, the amniotic fluid concentrations of both laminin and type IV collagen were within normal limits in spite of an elevated amniotic fluid AFP.     

Prolactin in amniotic fluid: its correlation with maternal plasma prolactin.

Prolactin concentrations in amniotic fluid from 319 women with normal pregnancies and 29 women with complicated pregnancies were determined by radioimmunoassay. Prolactin levels varied from 36 ng/ml to 1800 ng/ml mean +/- S.D. = 408 +/- 297) in the normal pregnancy group but showed no definite pattern of rise or fall during pregnancy. No difference in levels was found in complicated pregnancies. Prolactin concentrations in the plasma from 203 of these women were also assayed. The levels in the amniotic fluid were about 9 fold higher than those in the plasma. There was no significant correlation between amniotic fluid and plasma levels of prolactin.     

Measurement, Characterization, and Source of Somatostatin-like Immunoreactivity in Human Amniotic Fluid

Somatostatin-like immunoreactivity (SLI) is widely distributed in tissues and biological fluids. To determine whether SLI is also present in amniotic fluid, samples obtained by amniocentesis from 30 normal and 27 abnormal pregnancies were studied by radioimmunoassay. Direct incubation of [(125)I-Tyr(1)]tetradecapeptide somatostatin (SRIF) with amniotic fluid resulted in 89% tracer degradation. Damage was reduced to <5% when samples were acidified and boiled before the assay. With this technique, SLI was detectable in all normal amniotic fluid samples; the mean level at 15-20 wk of gestation (320+/-55 pg/ml, n = 15) being 4.5 times higher than the mean at 32-43 wk (70+/-12 pg/ml, n = 15) (P < 0.001). In cases of preeclampsia (n = 6), gestational diabetes (n = 5), anencephaly (n = 1), and meningomyelocele (n = 1), SLI values were in the normal range, but in one juvenile diabetic and one patient with chronic renal failure, SLI was undetectable (<10 pg/ml). In a pair of monochorionic diamniotic twins, SLI levels were very different (33 and 197 pg/ml), which suggests that fetal factors are more important than materno-placental ones in determining amniotic fluid SLI. Serial dilutions of amniotic fluid showed parallelism with standard SRIF. When concentrates of pooled amniotic fluid were chromatographed on Sephadex G-25 columns, all SLI eluted in the void volume ahead of SRIF even after treatment with 8 M urea and dithiothreitol. This "big" SLI incubated in amniotic fluid showed 100% stability over 24 h at 37 degrees C, whereas SRIF was rapidly inactivated (t((1/2)) congruent with 7 min). Extracts of placenta and fetal membranes contained no SLI, but small amounts (6-20% of total amniotic fluid SLI) were found in cells from fresh fluid. Radioimmunoassay of SLI in extracts of seven paired cord arterial and venous plasma samples showed no arteriovenous gradient consistent with fetal origin of cord blood SLI. It is concluded that (a) amniotic fluid contains SLI which is of fetal origin and (b) normal levels vary with gestational age. The SLI has a higher molecular weight (>/=5,000) and is more stable in amniotic fluid than SRIF.     

Pharmacokinetics and transplacental passage of imipenem during pregnancy.

Imipenem pharmacokinetics were studied in early pregnancy (n = 7; length of gestation, 8.6 +/- 1.5 weeks, mean +/- standard deviation), in late pregnancy (n = 7; length of gestation, 38.7 +/- 1.4 weeks), and in the nonpregnant state (n = 6). A single dose of 500 mg of imipenem-cilastatin (1:1) was administered as a 20-min infusion. Multiple plasma and urine samples, as well as specimens of umbilical plasma and amniotic fluid from the pregnant subjects, were collected at frequent intervals for 8 h. Imipenem concentrations were assayed by specific microbiologic assay. The mean peak concentrations in plasma were 14.7 +/- 4.9, 14.9 +/- 5.2, and 43 +/- 28.3 micrograms/ml in early pregnancy, late pregnancy, and the nonpregnant state, respectively. The volumes of distribution were significantly larger during early pregnancy (0.98 +/- 0.45 liter/kg of body weight, P < 0.005) and late pregnancy (0.59 +/- 0.19 liter/kg, P < 0.05) than in the nonpregnant state (0.33 +/- 0.10 liter/kg), and total clearances from plasma were faster in early pregnancy (12.7 +/- 7.8 ml min-1 kg-1, P < 0.05) and late pregnancy (10.7 +/- 4.6 ml min-1 kg-1, P < 0.05) than in the nonpregnant state (5.77 +/- 1.19 ml min-1 kg-1). The mean concentrations in amniotic fluid were 0.07 +/- 0.01 and 0.72 +/- 0.85 micrograms/ml in early and late pregnancy. The mean umbilical venous and arterial drug concentrations were 1.72 +/- 1.22 and 1.64 +/- 1.22 micrograms/ml. The feto-maternal ratio at the time of cesarean section was 0.33 +/- 0.12. These results indicate that an adjustment of doses of imipenem may be required when treating pregnant women because of considerable changes in imipenem pharmacokinetics during pregnancy.     

Serum hyaluronan and aminoterminal propeptide of type III procollagen: variation with age.

The serum levels of hyaluronan and the aminoterminal propeptide of Type III procollagen (PIIINP) were compared in 585 healthy individuals as a function of age. Newborn children displayed high hyaluronan (695 +/- 634 micrograms l-1, mean +/- SD) and PIIINP (295 +/- 152 micrograms l-1) values. The values were not correlated to the gestational week in which the children were born or to the birth weight but there was a significant correlation (p < 0.05) between the hyaluronan and PIIINP levels. During the first year the levels dropped and in childhood (1-16 years of age) both hyaluronan and PIIINP levels were fairly constant at 27 +/- 16 and 22 +/- 8.4 micrograms l-1, respectively. The PIIINP level showed a marked drop in adults compared to children. The drop continued to about 50 years of age (6.5 +/- 2.2 micrograms l-1) and then there was a slight increase in elderly people. The hyaluronan showed a continued increase with age from the level at 16 years of 29 +/- 17 micrograms l-1 to a mean value of 177 +/- 133 micrograms l-1 in people over 75 years. There was no increase in serum hyaluronan in women during pregnancy but the PIINP level increased in the later part of the gestational period. There was no correlation between the serum values of hyaluronan and PIIINP when compared throughout the life span which indicates that the blood levels of the two markers are regulated by independent factors.     

Pharmacokinetics of cefoperazone in full-term and premature neonates.

The pharmacokinetics of cefoperazone were evaluated in 28 newborn infants who were being treated for sepsis. A dose of 50 mg/kg was administered intravenously on days 0 to 2 in all, with a second dose administered on days 5 to 7 in 14 infants. Cerebrospinal fluid penetration was also studied in seven neonates. The mean peak concentration of cefoperazone in the serum of premature infants less than 33 weeks of gestational age, 159 (standard deviation, +/- 22) micrograms/ml, was higher than concentrations in premature infants 33 to 36 weeks of age and full-term infants (110 +/- 41 and 109 +/- 29 micrograms/ml, respectively). The mean concentrations 24 h after dosage were similar in all three groups, 13 to 17 micrograms/ml. The mean serum half-lives were similar in the three subgroups and ranged from 7 to 9 h. After the dose at 5 to 7 days, mean blood levels in the subgroups at 0.5 h were 149, 112, and 112 micrograms/ml; 24-h levels ranged from 9 to 12 micrograms/ml. The mean serum half-lives ranged from 5 to 7 h. Cerebrospinal fluid levels in patients with meningitis ranged from 2.8 to 9.5 micrograms/ml and in patients without meningitis from 1 to 7 micrograms/ml. Peak blood levels were 15 to 1,000 times higher than the 90% minimal inhibitory concentration of common pathogens found in newborns. These observations support the potential efficacy of cefoperazone in treatment of infections, including meningitis, in newborn infants.     

The effects of low dose insulin infusions on the renin angiotensin and sympathetic nervous systems in normal man

To examine the effects of physiological insulin concentrations on the renin-angiotensin and sympathetic nervous systems, healthy volunteers were studied by the euglycaemic glucose clamp technique with sequential 60 min 0.5 and 1.0 mU kg-1 min-1 insulin infusions and, subsequently, by a control infusion simulating clamp conditions. Plasma renin activity increased from 0.8 +/- 0.1 ng ml-1 h-1 basally to 1.0 +/- 0.2 ng ml-1 h-1 during the 0.5 mU infusion to 1.4 +/- 0.1 ng ml-1 h-1 during the 1 mU infusion but did not change during control infusion (0.9 +/- 0.3 ng ml-1h-1 to 0.9 +/- 0.2 ng ml-1h-1 to 1.0 +/- 0.1 ng ml-1h-1) (P less than 0.001 insulin vs. control by ANOVAR). Plasma angiotensin II increased during insulin (21.2 +/- 1.8 to 25.2 +/- 2.3 to 29.3 +/- 2.4 pg ml-1) but not during control infusion (24.0 +/- 2.8 to 23.6 +/- 2.6 to 23.5 +/- 2.5 pg ml-1) (P less than 0.001 insulin vs. control). Serum aldosterone did not change significantly during either infusion (insulin: 239 +/- 89 pmol l-1 to 237 +/- 50 pmol l-1 to 231 +/- 97 pmol l-1, control: 222 +/- 79 to 237 +/- 50 to 213 +/- 97 pmol l-1). Plasma noradrenaline increased to a greater extent during insulin (1.03 +/- 0.2 to 1.14 +/- 0.8 to 1.27 +/- 0.17 nmol l-1) than control infusion (0.86 +/- 0.09 to 0.97 +/- 0.09 to 0.99 +/- 0.09 nmol 1-1 (P less than 0.01 insulin vs. control). Changes in mean systolic blood pressure during insulin infusion were significantly different from control (+ 3 vs. -4 mmHg, P less than 0.001). In conclusion acute hyperinsulinaemia within the physiological range increases circulating hormones of the renin-angiotensin and sympathetic nervous systems and also increases systolic blood pressure.     

Perinatal outcome in monochorionic twin pregnancies complicated by amniotic fluid discordance without severe twin-twin transfusion syndrome.

OBJECTIVES: To assess the natural history and perinatal outcome in monochorionic diamniotic twin pregnancies with discordant amniotic fluid volume without signs of severe twin-twin transfusion syndrome (TTTS). METHODS: This was an observational study of 84 consecutive monochorionic twin pregnancies which did not meet the criteria for severe TTTS and endoscopic laser coagulation of placental anastomoses at initial presentation. The population was subdivided into two groups. Group 1 consisted of 64 pregnancies (median gestational age, 20.1 (range, 15.6-24.7) weeks) with amniotic fluid discordance and no signs of congestive heart failure in the twin with the larger amniotic fluid volume (Twin 1) and positive end-diastolic flow in the umbilical artery of the twin with the smaller amniotic fluid volume (Twin 2). Group 2 (median gestational age, 19.1 (range, 16.0-24.4) weeks) consisted of 20 pregnancies with amniotic fluid discordance and intrauterine growth restriction (IUGR) (abdominal circumference < 5th percentile) in combination with absent or reversed end-diastolic (ARED) flow in the umbilical artery of Twin 2. After exclusion of one patient from Group 1, who opted for termination of pregnancy, nine patients in Group 1 and one in Group 2 developed severe TTTS, and laser coagulation was offered. The remaining 54 pregnancies of Group 1 were compared with the remaining 19 pregnancies of Group 2. RESULTS: Fetuses in Group 1 showed significantly higher survival rates (overall survival, 100/108 (92.6%) vs. 23/38 (60%), P < 0.0001; survival of both fetuses, 49/54 (90.7%) vs. 9/19 (47.4%), P = 0.0002) and median gestational age at delivery (33.6, (range, 27.6-37.8) weeks vs. 32.0 (range, 26.9-36.3) weeks, P = 0.0457). Overall, there was a significantly higher incidence of complications, defined as necessity for intrauterine intervention, fetal or neonatal death or delivery prior to 32 weeks, in Group 2 (Group 1: 30/63 (47.6%); Group 2: 16/20 (80%), P = 0.0188). CONCLUSIONS: Our data suggest that amniotic fluid discordance in monochorionic diamniotic twin pregnancies in combination with IUGR and umbilical artery ARED flow in one fetus represents an extremely high-risk constellation for adverse pregnancy outcome.     

PHARMACOKINETICS OF LIDOCAINE AND BUPIVACAINE IN RETROBULBAR AND FACIAL BLOCK

Analgesia can be obtained during ophthalmic surgery by regional anesthesia using local anesthetic agents. As in other indications, neurological complications may occur, especially because the site of injection is close to the central nervous system. In order to evaluate the risk of retrobulbar and facial block obtained after 40 mg lidocaine and 20 mg bupivacaine injection, pharmacokinetics of both drugs was evaluated in plasma obtained from 11 patients. In addition, 3 cerebrospinal fluid samples were analyzed. Maximal plasma concentration was 0.73 +/- 0.33 micrograms.ml-1 for lidocaine and 0.19 +/- 0.06 micrograms.ml-1 for bupivacaine, obtained 24.7 +/- 23.0 min and 12.0 +/- 3.7 min after the end of injection, respectively. CSF/plasma ratio was in the range 0.05-0.26 for lidocaine and 0.56-1.33 for bupivacaine. In all patients, regional anesthesia was sufficient to perform surgery without any other analgesic drug. No sign of cardiovascular or respiratory toxicity was observed during the study.     

Exercise-induced changes in insulin-like growth factors and their low molecular weight binding protein in healthy subjects and patients with growth hormone deficiency

Serum concentrations of insulin-like growth factors 1 and 2 (IGF-1 and IGF-2), the low molecular weight form of IGF binding protein (IGFBP-1), insulin, C-peptide and GH were determined in six healthy subjects and four patients with GH deficiency during 30 min of moderate physical exercise on the cycle ergometer. The load corresponded to 60% of individual maximal oxygen uptake. IGF-1 and IGF-2 were determined by radioimmunoassays developed with antibodies isolated from immunized hens eggyolk after separation by automated acid gel filtration of serum samples prior to assay. Significant increases in the serum concentrations (mean +/- SEM) of IGF-1 (157 +/- 24 to 196 +/- 29 micrograms l-1, P less than 0.05) and IGF-2 (451 +/- 37 to 678 +/- 85 micrograms l-1, P less than 0.01) were seen in the healthy subjects after 10 min of exercise. The mean percentage increase was 26 +/- 5% for IGF-1 and 50 +/- 11% for IGF-2. No relation to the GH release was found. In GH-deficient patients the mean IGF-2 concentration rose 48 +/- 17% from basal 216 +/- 63 micrograms l-1 to a peak concentration of 324 +/- 115 micrograms l-1 (P less than 0.01) after 30 min, while the 38 +/- 20% rise of IGF-1 from basal 36 +/- 13 micrograms l-1 to a peak concentration of 55 +/- 27 micrograms l-1 was not significant. The serum IGFBP-1 concentration did not change during exercise, while insulin and C-peptide concentrations, as well as blood glucose, decreased in both healthy subjects and GH-deficient patients.(ABSTRACT TRUNCATED AT 250 WORDS)     

Reactivity of amniotic fluid alpha-fetoprotein with concanavalin A-sepharose in pre-natal diagnosis of fetal malformations

The proportion of concanavalin A-non-reactive alpha-fetoprotein was determined in 215 amniotic fluid samples from second trimester pregnancies. the median percentage for concanavalin A-non-binding alpha-fetoprotein was 35.5% at the 15th week and 32.2% at the 18th gestational week. Nineteen of the 23 pregnancies with various fetal malformations showed highly elevated total alpha-fetoprotein levels. In this group, the value for non-reactive alpha-fetoprotein was below the normal range in 12 out of 13 samples collected at 15-17 weeks of pregnancy and in four out of six samples at 18-19 weeks. Four pathological pregnancies had only moderately elevated total alpha-fetoprotein levels (5.3-7.9 SD above the mean) and two of these samples had a low percentage of the concanavalin A-non-binding fraction. The amniotic fluid alpha-fetoprotein concentration was between 3 and 5 SD and over 5 SD above the mean in four and seven normal pregnancies, respectively. The concanavalin A-fractionation classified correctly 10 out of these 11 cases. The results indicate that the determination of the proportion of concanavalin A-non-binding alpha-fetoprotein is a useful supplementary test to the total alpha-fetoprotein assay.     

Intracellular free calcium concentration and thromboxane A2 formation of vascular smooth muscle cells are influenced by fish oil and n-3 eicosapentaenoic acid.

The effect of fish oil and n-3 eicosapentaenoic acid (EPA) on intracellular free calcium concentration ([Ca2+]i) and thromboxane B2 (TXB2) formation in resting and stimulated cultured rat vascular smooth muscle cells (VSMC) was examined. In resting control cells [Ca2+]i was 147 +/- 15 nmol l-1 (mean +/- SEM, n = 4). After pretreatment of the cells with fish oil or EPA for 24 days the resting [Ca2+]i was decreased to 126 +/- 10 nmol l-1 and 84 +/- 8 nmol-1, respectively. After stimulation of untreated control cells with either 100 nmol l-1 angiotensin II (AII), 40 micrograms ml-1 low-density lipoprotein (LDL), or 100 ng ml-1 of recombinant platelet-derived growth factor (PDGFAB), [Ca2+]i was (in nmol l-1) 306 +/- 31, 217 +/- 25 and 213 +/- 16. Treatment of cells with fish oil or EPA reduced the stimulatory effect of the agonists, and the following [Ca2+]i values (in nmol l-1) were found: 199 +/- 21, 131 +/- 10, 148 +/- 13; and 175 +/- 11, 98 +/- 12, and 103 +/- 6, respectively. PDGFAB induced a four fold increase in TXB2-generation (270 +/- 28 pg mg-1 cell protein compared with 61 +/- 8.2 pg mg-1 in unstimulated control cells) within 6 min. In cells pretreated with fish oil or EPA, TXB2-formation was reduced by 54% and 44%, respectively. In conclusion: in rat VSMC stimulated by a variety of vasoactive agonist, fish oil and EPA can markedly attenuate intracellular mechanisms related to changes of cytosolic calcium concentration and eicosanoid production.(ABSTRACT TRUNCATED AT 250 WORDS)     

Tetranectin in amniotic fluid, maternal serum and fetal fluids

The concentration of the newly discovered protein tetranectin has been measured in different fetal and maternal compartments. In amniotic fluid a significant, positive correlation between the tetranectin concentration and gestational age was found (a mean of 0.2 mg l-1 at week 14 to a mean of 0.5 mg l-1 at week 21). In maternal serum a slight negative correlation was found between tetranectin concentration and gestational week (a mean of 6.17 mg l-1 at week 14 to a mean of 5.79 mg l-1 at week 21). In-term cord blood collected at delivery a mean level of 6.0 mg l-1 was found, and no difference was found between arterial- and venous-blood tetranectin concentration. In fetal serum the overall mean level was 2.6 mg l-1 and a significant positive correlation between tetranectin concentration and gestational age was found. The mean level was 1.1 mg l-1 in fetal cerebrospinal fluid and no correlation to gestational age was found. Fetal tetranectin may, therefore, be correlated to fetal maturation.     

Lipoprotein-induced modulation of cyclosporine-A-mediated immunosuppression

Human serum lipoproteins form complexes with cyclosporine-A and act as a carrier of cyclosporine-A in vivo. We compared the immunosuppressive effects of free cyclosporine-A, a complex composed of cyclosporine-A and lipoproteins, free cyclosporine-A in the presence of each unbound lipoprotein, and each lipoprotein without cyclosporine-A with one another at concentrations comparable with in vivo conditions on PHA-stimulated peripheral blood mononuclear cells. Free cyclosporine-A reduced the proliferation of the PHA-stimulated mononuclear cells to 50% at a concentration of 300 ng ml-1 (SD +/- 30, n = 12) lipoprotein-deficient medium. Cyclosporine-A loaded into VLDL showed a 50% proliferation rate reduction at 60 micrograms VLDL ml-1 (SD +/- 10, n = 12) and 180 ng cyclosporine-A ml-1. In the presence of 100 ng ml-1 cyclosporine-A 180 micrograms ml-1 VLDL (SD +/- 25, n = 12) showed a proliferation rate reduction of 50%. In the same way VLDL without cyclosporine-A induced a reduction to 50% at 740 micrograms ml-1 (SD +/- 30, n = 12). Cyclosporine-A loaded into LDL showed a 50% proliferation rate reduction at 27 micrograms ml-1 LDL (SD +/- 5, n = 12) with 80 ng ml-1 cyclosporine-A. In the presence of 100 ng ml-1, cyclosporine-A 150 micrograms ml-1 LDL (SD +/- 25, n = 12) showed a proliferation rate reduction of 50%. In the same way, LDL without cyclosporine-A induced a reduction to 50% at 950 micrograms ml-1 (SD +/- 50, n = 12).(ABSTRACT TRUNCATED AT 250 WORDS)     

Thrombin—antithrombin III complex in fulminant hepatic failure: evidence for disseminated intravascular coagulation and relationship to outcome

Indirect evidence has suggested that intravascular coagulation may occur in patients with fulminant hepatic failure (FHF), the most severe form of acute liver disease. Thrombin is inhibited in circulation by antithrombin III, and measurement of the thrombin-antithrombin III complex (TAT) is a direct measure of thrombin formation. Using a new rapid enzyme-linked immunosorbent assay we have measured TAT in 54 patients on admission, with fulminant hepatic failure. TAT was significantly increased in patients with FHF compared with control subjects (25.8 +/- 2.7 micrograms l-1) compared with 2.6 +/- 0.2 micrograms l-1; n = 10: P less than 0.001). Patients who survived had significantly lower TAT levels than those who did not (17.2 +/- 2.7 micrograms l-1; n = 27 compared with 34.0 +/- 4.2 micrograms l-1; n = 27: P less than 0.005) and patients with FHF caused by viral hepatitis had significantly lower TAT levels than those with FHF due to paracetamol overdose (14.6 +/- 4.7 micrograms l-1; n = 9 compared with 28.0 +/- 3.1 micrograms l-1; n = 45: P less than 0.05). Levels of TAT correlated significantly with prothrombin time (r = 0.36, P less than 0.01) and inversely with fibrinogen (r = -0.51, P less than 0.001). There was no significant correlation with antithrombin III concentration. Thus, using a simple and rapid technique, we have been able to demonstrate increased levels of TAT complex in patients with FHF. This provides more direct evidence of intravascular coagulation and thrombin generation in these patients. These results confirm that the coagulation system is activated in FHF.     

Fetal ossification centers as predictors of gestational age in normal and abnormal pregnancies.

The main fetal ossification centers appear ultrasonically as egg-shaped echo-rich areas. The calcaneal and talar ossification centers are seen at the level of the tarsus osseus, and the distal femoral epiphyseal and proximal tibial epiphyseal ossification centers are found at the level of the knee. Examination of 312 normal pregnancies between 20 and 40 weeks of gestation showed that the calcaneal ossification center was detectable for 24 weeks of gestation, the talar ossification center from 26 weeks, and the distal femoral epiphyseal and proximal tibial epiphyseal ossification centers, from 32 and 36 weeks, respectively. Corresponding figures found for 36 pregnancies showing intrauterine growth retardation (IUGR), examined between 34 and 40 weeks of gestation, were similar for the calcaneal and talar ossification centers but showed delays in the development of the epiphyseal ossification centers, which were particularly striking in cases of symmetrical IUGR. The amniotic fluid lecithin/sphingomyelin ratio was also evaluated in 51 normal pregnancies between 31 and 38 weeks of gestation and was found to be greater than or equal to 2 in every case where the distal femoral epiphyseal ossification center was greater than or equal to 6 mm in diameter. Evaluation of fetal ossification centers may be another useful means to evaluate gestational age in late pregnancy