Estudios del laboratorio de diversos parámetros orientados a tratar de dilucidar la fisiopatología del síndrome de ovarios poliquísticos (SOP). Parte 2 / Laboratory studies of several parameters aimed to elucidate the pathophysiology of polycystic ovary syndrome. Second part

RESUMEN Diversos estudios bioquímicos adicionales a la evaluación de Testosterona total (TT), biodisponible (Tbio) y libre (TL) han sido realizados a los efectos que pudieran resultar de mayor utilidad para el diagnóstico de patologías concomitantes en el SOP, entre otros. En la hormona anti Mülleriana, cuando la concentración supera a los 3,0 ng/ml existen evidencias de que el 79% de las mismas pueden ser identificadas correctamente como SOP. El Antígeno Prostático Específico (PSA), marcador de singular importancia en pacientes con cáncer de Próstata, con técnicas ultrasensibles ha podido ser detectado en más del 50% en mujeres. En un grupo de pacientes con SOP, los niveles circulantes de PSA fueron significativamente mayores que en las mujeres sin SOP. El Kiss-1 aislado de la placenta y demostrado en otros tejidos, presenta niveles aumentados que correlacionan con la LH, TT, TL y resistencia a la insulina (RI) en adolescentes con SOP versus adolescentes sin SOP, sugiriendo que el Kiss-1 podría estar involucrado en el desarrollo del SOP en estas pacientes. Algunas pacientes con SOP están asociadas a patologías relevantes, de las cuales han sido comunicadas el aumento del BMI, mayor grado de dislipemia, adiposidad central, RI y Síndrome Metabólico (SMe). En las pacientes con un fenotipo clásico (hiperandrogenismo, alteración del ciclo menstrual y ovarios poliquísticos), estas patologías son de mayor frecuencia y severidad que en los otros fenotipos, particularmente aquellos sin hiperandrogenismo. Otras determinaciones como TNFα, interleuquinas, test de tolerancia a la glucosa, ApoB, partículas pequeñas de LDL e Inhibidor del Activador del Plasminógeno-1 han sido comunicados que podrían ser de utilidad para tener mayor sensibilidad en la definición de patología concomitantes en el SOP. Actualmente se ha comenzado a evaluar otros marcadores como el Fetuin-A; Quemerina, Nesfatina-1, Neopterina y Endocannabinoides, cuyos resultados preliminares parecerían ser un aporte importante para evaluar SMe y RI en paciente con SOP y tratar de definir su prevalencia en los distintos fenotipos de esta patología.

ABSTRACT Several biochemical studies in addition to the evaluation of total Testosterone (TT), bioavailable (bioT) and free (FT) have been performed to the effects that could be of greater use for the diagnosis of concomitant pathologies in the PCOS, among others. The anti-Müllerian hormone whose concentration when exceeds 3.0 ng/ml, there is evidence that 79% of these patients can be correctly identified as PCOS. The Prostate-Specific Antigen (PSA), a marker of singular importance in patients with prostate cancer, with ultra-sensitive techniques, has been detected in more than 50% of women. In a group of patients with PCOS, circulating levels of PSA are significantly higher than in women without PCOS. The Kiss-1 isolated from the placenta and demonstrated in other tissues, has increased levels that correlate with LH, TT, TL and insulin resistance (IR) in adolescents with PCOS respect to adolescents without PCOS, suggesting that Kiss-1 could be involved in the development of the PCOS in these patients. In some patients with PCOS, they are associated with relevant pathologies, of which the increase in BMI, higher degree of dyslipidemia, central adiposity, IR and Metabolic Syndrome (MeS) have been reported. Those that show a classic phenotype (hyperandrogenism, alteration of the menstrual cycle and polycystic ovaries) these characteristics are of greater frequency and severity than in the other phenotypes, particularly those without hyperandrogenism. Other determinations such as TNFα, interleukins, glucose tolerance test, ApoB, small particles of LDL and Plasminogen Activator Inhibitor-1 have been reported that could be useful to have greater sensitivity in the definition of concomitant pathology in the PCOS. Currently, other markers such as Fetuin-A, Chemerin, Nesfatin-1 Neopterin and Endocannabinoids have been evaluated. The preliminary results suggest to be an important contribution to define MeS and IR in patient with PCOS and to try to determine its prevalence in the different phenotypes of this pathology.

Estudios de laboratorio de diversos parámetros orientados a tratar de dilucidar la fisiopatología del síndrome de ovarios poliquísticos. Parte 1 / Laboratory studies of various parameters aimed at trying to elucidate the pathophysiology of polycystic ovary syndrome. Part 1

Esta revisión fue realizada con el fin de evaluar nuestros resultados de laboratorio así como aquellos de la literatura que constituyen, a nuestro entender, aportes significativos en el síndrome de ovarios poliquísticos (SOP). Nuestro especial énfasis será presentar las limitaciones de las metodologías empleadas por nuestro grupo, comparativamente a las reportadas por otros investigadores. La determinación de andrógenos, en particular de Testosterona (TT), es quizá la de mayor complejidad dado que los resultados con los diferentes inmunoensayos empleados en nuestro medio producen resultados muy variables por los diferentes métodos y aún entre laboratorios que usan la misma metodología. La técnica de referencia es la cromatografía líquida en tándem con espectrometría de masa (LC-MSMS), de difícil aplicación en laboratorios de análisis clínicos debido a su alto costo y la imposibilidad de resolver numerosas muestras. En estudios previos demostramos que de los métodos habitualmente usados para evaluar la TT circulante, solo en 2 inmunoensayos los resultados obtenidos fueron satisfactoriamente validados indirectamente según el criterio del Consenso de los Centros para el Control y Prevención de Enfermedades (CDC, USA) contra LC-MSMS, los cuales fueron comparables a dicha metodología con niveles superiores a 0,5 ng/ml. El SOP puede presentar factores de riesgo aumentados para la enfermedad cardiovascular y la diabetes II. Estos factores no están debidamente categorizados en función de los distintos fenotipos del SOP. Se evaluarán los principales analitos empleados con este objetivo y los nuevos que aporten elementos de mayor especificidad en este sentido

This review was performed in order to evaluate our laboratory results as well as those of the literature that constitute, in our opinion, significant contributions in these pathophysiologies. Our special emphasis will be on presenting the limitations of the methodologies used by our group, compared to those reported by other researchers. The determination of androgens, in particular Testosterone (TT), is perhaps the most complex since the results with the different immunoassays used in our environment produce very variable results by the different methods and even between laboratories that use the same methodology. The reference technique is LC-MSMS, difficult to apply in clinical analysis laboratories because of its high cost and the inability to solve numerous samples. In previous studies, we demonstrated that, in comparison to LC-MSMS with the usual methods for evaluating circulating TT, the results obtained in only 2 immunoassays were satisfactorily validated indirectly according to the criteria of CDC against LC-MSMS, which were comparable to that methodology with levels higher than 0.5 ng/ml. PCOS may have increased risk factors for cardiovascular disease and diabetes II. These factors are not properly categorized according to the different phenotypes of PCOS. The main analytes used for this purpose will be evaluated and new ones that contribute elements of greater specificity in this sense

Herman score in prenatal screening for Down syndrome: Can a junior assess a senior?

PURPOSE: To compare Herman scores self-assessed prospectively during ultrasound first-trimester screening by a single senior radiologist with 15 years of experience, to those obtained retrospectively by an unexperienced junior radiologist. MATERIALS AND METHODS: Over a 18-month period, a single senior radiologist measured the nuchal translucency thickness along with calculation of Herman scores. An independent junior radiologist subsequently reviewed and scored the images. RESULTS: A total of 301 patients were included. The mean Herman score was 8.2±0.9 (SD) for the senior radiologist and 7.8±0.9 (SD) after review by the independent junior radiologist (P<0.001). The scores for caliper position and fetal head position decreased significantly after the independent review. The two criteria on which the two operators disagreed the least were visualization of the nuchal translucency and the distinction between neck and amnios. CONCLUSION: Herman score is lower after review by a junior radiologist, without any effect on patient's management and follow-up.

Prenatal diagnosis of bowel malposition using T2-weighted fetal MRI sequences.

OBJECTIVE: The goal of this study was to investigate the capability of T2-weighted magnetic resonance imaging (MRI) in revealing fetal bowel malposition. MATERIALS AND METHODS: All fetal MRI examinations (excluding central nervous system MRI examinations) performed in our department from January 2005 to January 2014 were retrospectively studied by 2 independent observers for situs, stomach and jejunum location on T2-weighted images. Patients data were also reviewed for results of ultrasound examinations, MRI indication, and gestational age. Abnormally positioned jejunums were classified into 3 groups: intrathoracic (A), extra-fetal (B) and abnormal intra-fetal (C). Prenatal data were compared to postnatal imaging, surgery or autopsy findings that served as standard of reference. RESULTS: A total of 709 fetal MRI examinations were analyzed. In 64 fetus (9%), the jejunum was not present in the left subgastric area on T2-weighted MR images. In these 64 fetuses, proximal jejunum was intrathoracic (41/64, 64%, group A), extra-fetal (11/64, 17%, group B), or intra-abdominal but abnormally positioned (12/64, 19%, group C). Interobserver agreement was 100%. All diagnoses for fetuses in groups A and B (52 cases) were confirmed postnatally (41 cases) or at autopsy (11 cases). In group C, bowel malposition was suspected after ultrasound in only 2/12 fetuses (16.6%); it was confirmed postnatally in 1 fetus but not confirmed in the remaining one. In the 10 remaining fetuses (83%), malposition was confirmed postnatally although not initially suspected. CONCLUSION: T2-weighted fetal MR images are useful for the prenatal diagnosis of bowel malposition, even when they are unsuspected on ultrasound examination.

Cosecretion of glycosylated prolactin and non-glycosylated prolactin from childhood to the end of puberty.

BACKGROUND: Glycosylated prolactin (G-PRL) is considered as the major post-translational modification of prolactin (PRL) showing reduced lactotropic and mitogenic activities compared to non-glycosylated prolactin (NG-PRL). AIM: To evaluate the evolution of G-PRL in normoprolactinemic children and adolescents and to analyze possible variations in glycosylated/total prolactin (T-PRL) ratios. METHODS: T-PRL, G-PRL and NG-PRL were evaluated in 111 healthy female and male children and adolescents (4.1-18 years), classified as group 1 (Tanner I), group 2 (Tanner II-III) and group 3 (Tanner IV-V). G-PRL and NG-PRL were identified by chromatography on concanavalin-A-Sepharose. RESULTS: G-PRL/T-PRL (median-range): females, group 1: 0.59 (0.17-0.77), group 2: 0.56 (0.31-0.78), group 3: 0.60 (0.38-0.79); males, group 1: 0.64 (0.39-0.80), group 2: 0.61 (0.24-0.79), group 3: 0.62 (0.35-0.90); the p value is not significant among the different groups in both genders. G-PRL/T-PRL ratios do not change when comparing low (first quartile) versus high (third quartile) T-PRL levels in the different groups. CONCLUSION: Our study would appear to support cosecretion of G-PRL and NG-PRL from childhood to the end of puberty. Such cosecretion would not be dependent on sex steroid levels. It is important to point out that puberty does not change the proportions of G-PRL and NG-PRL.

[Management of fetal mediastinal shift: a practical approach]. / Conduite à tenir devant une déviation médiastinale fœtale: une approche pratique.

The purpose of this article is to review the technique of fetal chest ultrasound screening evaluation, the diagnostic work-up in the presence of fetal mediastinal shift and which ultrasound imaging features to look for. The first step in evaluating the fetal thorax is to confirm situs. Then, a median sagittal line is drawn from a four-chamber view to assist in spatial orientation followed by echotexture analysis of the structures of the thorax in the presence of mediastinal shift. We propose a systematic approach based on the direction of the mediastinal shift and echogenicity of the compressing hemithorax. When the hemithorax contralateral to the mediastinal shift is enlarged, which is the most frequent situation, diaphragmatic hernia and macrocystic congenital cystic adenomatoid malformation are the most likely etiologies when the mass is heterogeneous. Microcystic congenital cystic adenomatoid malformation, sometimes associated with sequestration, is the most frequent etiology when the mass is homogeneous. When the hemithorax ipsilateral to the mediastinal shift is small, which is less frequent, and the contralateral hemithorax is homogeneously isoechoic, then a diagnosis of lung hypoplasia-agenesis-aplasia should be considered.

Magnetic resonance imaging in the prenatal diagnosis of congenital diarrhea.

OBJECTIVE: Congenital diarrhea is very rare, and postnatal diagnosis is often made once the condition has caused potentially lethal fluid loss and electrolyte disorders. Prenatal detection is important to improve the immediate neonatal prognosis. We aimed to describe the prenatal ultrasound and magnetic resonance (MRI) imaging findings in fetuses with congenital diarrhea. METHODS: The study reports the pre- and postnatal findings in four fetuses that presented with generalized bowel dilatation and polyhydramnios. We analyzed the fetal ultrasound and MRI examinations jointly, then compared our provisional diagnosis with the amniotic fluid biochemistry and subsequently with the neonatal stool characteristics. RESULTS: In each of the four cases an ultrasound examination between 22 and 30 weeks' gestation showed moderate generalized bowel dilatation and polyhydramnios suggesting intestinal obstruction. MRI examinations performed between 24 and 32 weeks' gestation confirmed that the dilatation was of gastrointestinal (GI) origin, with a signal indicating intraluminal water visible throughout the small bowel and colon. The expected hypersignal on T1-weighted sequences characteristic of physiological meconium was absent in the colon and rectum. This suggested that the meconium had been completely diluted and flushed out by the water content of the bowel. The constellation of MRI findings enabled a prenatal diagnosis of congenital diarrhea. The perinatal lab test findings revealed two cases of chloride diarrhea and two of sodium diarrhea. CONCLUSION: Congenital diarrhea may be misdiagnosed as intestinal obstruction on prenatal ultrasound but has characteristic findings on prenatal MRI enabling accurate diagnosis; this is important for optimal neonatal management.

Heterogeneity of circulating prolactin in the bitch.

Different molecular forms of circulating prolactin (PRL) are known to occur in several species. As no such information was available in dogs, we assessed the molecular profile of circulating PRL in bitches. Pooled sera from covertly (CTRL) and overtly pseudopregnant (PSPT) diestrous bitches with high or low (> 10 or < 10 ng x mL(-1), respectively) serum PRL (measured by ELISA) were analyzed by Sephadex G-100 and Concanavalin A-Sepharose column chromatography. Four serum PRL fractions were identified and termed big-big, big (> 67 kDa), native (23 kDa) and fragmented (< 20) kDa) PRL. The percentages of these fractions were roughly similar in CTRL and PSPT animals, irrespective of their serum PRL levels (higher in PSPT than in CTRL bitches). A large proportion of glycosylated PRL (between 69 and 100%) was also detected in these sera. We conclude that in dogs, circulating PRL occurs in multiple molecular forms, whose relative abundance is comparable in covertly and overtly pseudopregnant bitches.

Altered luteinizing hormone pulsatility in infertile patients with idiopathic oligoasthenozoospermia.

In a previous study, we demonstrated that oligoasthenozoospermic (OAZ) patients had two types of testosterone response to human chorionic gonadotrophin (HCG) administration: group 1 (OAZ-1) had an altered, monophasic (no first peak) response, and group 2 (OAZ-2) had a normal biphasic response. The objective of the present work was to study the luteinizing hormone (LH) pulsatility in OAZ-1 compared with both OAZ-2 and men of proven fertility (PF), in order partly to determine the possible aetiology of the blunted acute testosterone response to HCG in these patients. LH pulsatility was measured in 10 PF, 10 OAZ-1 and 10 OAZ-2 patients, in blood samples taken every 5 min for 6 h in PF, and for 4 h in OAZ patients. LH values were determined by a time-resolved immunofluorometric assay. Frequency and amplitude of the LH pulses were determined by a computer program. LH pulse frequency, expressed as pulses/4 h, was significantly lower in OAZ-1 (1.5+/-0.97) than in PF (2.4+/-0.63) and OAZ-2 (2.4+/-0.84) patients. In six OAZ-1 and two OAZ-2 patients, LH pulsatility was diminished, as they showed less than two pulses/4 h. No statistically significant differences in LH pulse amplitude were found. These results, together with a higher number of OAZ-1 cases found with decreased LH pulsatility, suggest that, at least in a subset of these men, quantitative and/or qualitative alterations of LH secretion might have occurred.

Recombinant human follicle-stimulating hormone administration increases testosterone production in men, possibly by a Sertoli cell-secreted nonsteroid factor.

We previously showed that recombinant human FSH (R-FSH) in males increased the testosterone (T) concentration in spermatic venous blood (SB). To investigate the effect of R-FSH on spermatic steroid levels and the action of steroid- and LH-free SB on isolated Leydig cells, nine normospermic males were studied during spermatic cord surgery. Peripheral blood and SB samples were collected before and 30 min after iv administration of 150 U R-FSH to measure LH, FSH, T, estradiol, 17alpha-hydroxyprogesterone, and sex hormone-binding globulin, and in SB, androstenedione (delta4) and dehydroepiandrosterone (DHEA) were also measured. LH bioactivity was assessed by in vitro production of T in isolated Leydig cells. The actions of R-FSH and SB (steroid and LH free) were analyzed in the bioassay. Data are expressed as the mean +/- SE. FSH in peripheral blood and SB increased by 411% and 477% after R-FSH administration. R-FSH induced a significant increase in spermatic T (basal vs. 30 min, 326.4 +/- 98.5 vs. 732.4 +/- 152.8 ng/mL; P < 0.047) and in spermatic estradiol (289.5 +/- 66.9 vs. 535.6 +/- 83.4 pg/mL; P < 0.036). The T/delta4 ratio (36.9 +/- 9.2 vs. 74.5 +/- 13.3; P < 0.019) and the T/DHEA ratio (10.8 +/- 1.1 vs. 22.4 +/- 4.9; P < 0.024) increased significantly. In isolated Leydig cells, R-FSH did not change T production, but the SB (steroid and LH free) after R-FSH administration induced an increase in T production (3.3 +/- 0.6 vs. 4.9 +/- 0.6 ng/tube; P < 0.04). LH-like activity was found in a more than 50,000-Da fraction after centrifugation in Amicon filters, even in the presence of anti-LH. These results suggest that R-FSH increases the production of T by Leydig cells through a Sertoli cell-released nonsteroid factor with a molecular mass greater than 50 kDa. The increase in the T/delta4 and T/DHEA ratios indicates that this factor would act by amplifying the LH response through the delta5 pathway and the 17beta-hydroxysteroid dehydrogenase enzyme.

HLA typing with monoclonal antibodies: evaluation of 356 HLA monoclonal antibodies including 181 studied during the 10th International Histocompatibility Workshop.

During the 10th International Histocompatibility Workshop (10th WS), 181 HLA MoAbs were studied using lymphocytotoxicity micro-technique (LCT) and/or enzyme immuno-assay (EIA), and their capacity to serve as typing reagents was evaluated. 129 MoAbs were tested by both techniques. Results obtained with 92 class I and 86 class II polymorphic MoAbs (10th WS) were compared to published data concerning 180 class I and 176 class II polymorphic MoAbs, listed in an HLA-MoAbs Register maintained in our laboratory. The following conclusions can be proposed: 1/HLA-A, B typing by LCT with MoAbs is possible for about 14 specificities. Some specificities are clearly recognized (HLA-A3, B8, B13, Bw4, Bw6), others are recognized as cross-reacting groups (B7+27+w22+40), others are not currently recognized by any MoAb with restricted specificity (B5, B15). Several MoAbs confirmed the existence of shared epitopes between products from a single locus (A2-A28, A25-A32), or from A and B loci (A2-B17, Bw4-A9-A32). A single HLA-Cw MoAb has been described. 2/HLA class II typing by LCT with MoAbs is more difficult than class I typing. DR2, DR3, DR4, DR5 and DR7 as well as DRw52 and DRw53 are well defined; other DR specificities are poorly or not at all defined. Particular associations (DR1+DR4, DR3+DRw6, all DR except DR7) are recognized by several MoAbs. All DQw specificities are well recognized, including new specificities defined only by MoAbs: WA (DQw4), TA10 (DQw7), 2B3 (DQw6+w8+w9). Only two HLA-DP MoAbs have been described. 3/Satisfactory results, similar to those of LCT, were obtained with EIA using lymphoid cell lines as targets. 4/Human MoAbs (12 in the Register) are satisfactory typing reagents. They could represent in the future a significant contribution to HLA typing with MoAbs.

Definition of a new supertypic HLA class II determinant (LAR) associated with HLA-DR2 and -DR7.

A serum from a patient (LAR), immunized by pregnancies and blood transfusions, reacted with cells carrying HLA-DR2 and/or -DR7 specificities (titer 1:200-1:1000). Absorption-elution experiments showed that the allo-serum recognized a determinant shared by DR2 and DR7 cells. The high correlation coefficients (0.90-1) with these specificities suggested that the supertypic specificity LAR was carried by the first DR molecule encoded by DRB1 gene. LAR is another example of new supertypic specificities, reflecting structural homologies between alleles at HLA class II loci.

[Study of the HLA-DQ system by the complement fixation test on lymphocytes stimulated by phytohemagglutinin. Existence of HLA-DQX allele(s)]. / Etude du système HLA-DQ par réaction de fixation du complément sur lymphocytes stimulés par la phyto-hémagglutinine. Existence d'allèle(s) DQX.

The complement fixation microtechnique against PHA blasts has been used to study HLA-DQw1, 2, 3 specificities with sera from multiple transfused patients and/or from multiparous women. Several sera (6 or 7) have been used to define each DQ specificity. The sera have been chosen because of their reactivity with cells from HLA-DR 1, 2 or w6 donors (for DQw1), DR3 or 7 donors (for DQw2,) DR4 or 5 donors (for DQw3). Correlation coefficients between DQ and DR specificities were from 0.56 to 0.91. Correlation coefficients between sera were from 0.51 to 0.92 in each cluster of sera. The segregation of DQw1, 2, 3 specificities has been studied in 46 families with 234 children. This study showed haplotypes lacking DQw1, 2, 3 specificities. The segregation of such 11 DQX haplotypes has been observed in 38 children from 8 families; 5 children were DQX/DQX homozygotes. Up to now, no serological reagent defining the specificity (or specificities) corresponding to DQX has been found. No preferential association was observed between DQX and DR specificities. The gene frequencies observed in 170 haplotypes in these 46 families were as follows: DQw1: 0.400; DQw2: 0.252; DQw3: 0.282; DQX: 0.065. Detecting DQ specificities seems easier by CF on PHA blasts than by lymphocytotoxicity microtechnique against B lymphocytes and monocytes from pheripheral blood. This suggests that PHA blasts express larger quantities of DQ molecules than B lymphocytes and monocytes. The results confirm that complement fixation microtechnique against PHA blasts is efficient for HLA-DQw typing.

[Various problems related to the use of multi-attachment appliances]. / Quelques incidents liés à l'utilisation des appareils à multi-attaches.

The authors review the lesions which may be seen during orthopedic treatment involving multi-attachment dentures which they use for their clinical cases. They emphasise that these iatrogenic lesions can be avoided by the use of moderate forces appropriately applied and the functional conception of orthopedic treatment.

Evidence for a new HLA class II determinant present on cells from HLA-DR1 and/or -DR4 individuals.

Evidence for a new HLA class II specificity is presented. It is recognized by LE serum, which reacts with most DR1 and/or DR4 individuals (r = 0.86). Its frequency in the French population is 0.33. Absorption-elution experiments showed that the serum reactivity was not due to a mixture of anti-DR1 and anti-DR4 antibodies, but to a single antibody population which could be absorbed on and eluted from both DR1(+) or DR4(+) cells. LE specificity seemed to be expressed on DR but not on DQ molecules since the serum reacted with and could be absorbed by DR+,DQw- cells; it did not react with a DR-,DQw+ mutant cell, but did react with the DR+,DQw+ parental cell. The relationship between LE specificity and MC1 and Te23 specificities remains to be determined.

Serological cross-reactivity between products of separate I regions.

A B10.S(7R) anti-B10.S(9R) serum (anti-IJEkCd) contained, as expected, antibodies specific for the I-E-subregion-encoded determinant Ia.7. However, tests on recombinant haplotypes demonstrated a series of unexpected weak extrareactions which could be interpreted to be directed against antigenic determinants encoded in the I-A subregion of the H-2 complex. The same type of extrareaction was observed in eluates from I-As, I-Ek cells coated with A.TH anti-A.TL (I-As, I-Ek anti-I-Ak, I-Ek) serum. This reactivity in serum and eluates could be interpreted as cross-reactivity between products of the I-E and I-A subregions.

Binding of prolactin by fetal human lung cell membrane fractions.

PRL binding capacity to cell membrane fraction was studied in lung tissues obtained from 4 human fetuses or newborn infants. One of the fetuses was a stillborn delivered at 33 weeks of gestation. The newborn infants died for unknown causes within 24 h after birth. The gestational age was 20, 39 and 41 weeks. The cell membrane fraction was prepared by ultracentrifugation. binding capacity and affinity constants were calculated according to athe Scatchard method. No significant specific binding of PRL to lung tissue from the stillborn fetus was observed, while for the other 3 newborn infants the binding capacity was 5.7, 7.4 and 9.6 fmol PRL bound/mg of membrane protein, respectively. The affinity constants were in the order of 10(10) M-1. these preliminary results show that human neonatal lung has receptors for PRL and suggest that PRL itself may be involved in the lung maturation.