Combination of two techniques: amniocentesis and nervous tissue explants. A pilot investigation

Addition of serum derived from amniotic fluid cells (AFS) from Tay Sachs carrier to developing mouse cerebral cortex explants results in excessive accumulation of lipid in neuronal cytoplasm.     

Combination of two techniques: Amniocentesis and nervous tissue explants. A pilot investigation

Summary Addition of serum derived from amniotic fluid cells (AFS) from Tay Sachs carrier to developing mouse cerebral cortex explants results in excessive accumulation of lipid in neuronal cytoplasm.Supported by Bronx VA Grant.I wish to thank Dr William Whetsell, Jr, and his laboratory at the Mt. Sinai School of Medicine, for their technical assistance.     

Analyses chromatographiques des corticoïdes extraits du liquide amniotique d'une femme diabétique

Summary Paper chromatography was applied to corticoids extracted from amniotic fluid of a diabetic mother.Normal amniotic fluid contains no 17-hydroxycorticosterone and cortisone, as defined by paper chromatography.The extract of amniotic fluid of a diabetic mother, insulin treated from the 4^th month and giving birth to a child with a congenital anomaly of cervical vertebras (Klippel-Feil syndrome) and with typical Cushing aspect, has been chromatographed. It contains 25–50µg of 17-hydroxycorticosterone and cortisone. The protein content of this fluid was 0.7 g %.     

Diagnosis of the presence of meconium in amniotic fluid by dispersion curves of the longitudinal relaxations of protons]

Dispersion curves of the longitudinal relaxation T1 of protons in healthy amniotic fluid in a meconium solution are distinct at low Larmor frequencies (V0 less than 100 kHz). We are thus able to distinguish these fluids by T1 measurements in this range.     

Sex chromatin analysis of unstained mouse amniotic cells using brightfield microscopy

Sex chromatin of unstained mouse amniotic cells was identifiable using ordinary brightfield microscopy with optimal setting of the illumination.     

Sex chromatin analysis of unstained mouse amniotic cells using brightfield microscopy

Summary Sex chromatin of unstained mouse amniotic cells was identifiable using ordinary brightfield microscopy with optimal setting of the illumination.     

Immunoactive TSH in the amniotic fluid of the rat

Summary Amniotic fluid was obtained from 19-day-old rat fetuses by aspiration. Pooled samples measured at 4 different dilutions demonstrated parallelism with standard rat TSH. It is concluded that rat amniotic fluid has TSH immunoactivity.This work was supported by Hong Kong University Research Grant No. 335/034/5727.The authors wish to acknowledge with thanks the gift of rat TSH RIA kit from Dr A. F. Parlow and the Rat Pituitary Programme of NIAMDD.     

Evidence for the existence of 2 types of α1-lipoprotein in amniotic fluid from pregnancies older than 20 weeks

Summary We have found by means of crossed immunoelectrophoresis that amniotic fluid contains 2 types of ₁-lipoprotein after the 20th week of pregnancy. Before that period the ₁-lipoprotein profile of amniotic fluid resembles that of serum and migrates as one type only.     

Variations of non conjugated steroids in the amniotic fluid during the last weeks of pregnancy]

Levels of cortisol, estradiol and progesterone were measured in 172 amniotic fluid samples collected by amniocentesis during late pregnancy. An increase in cortisol and estradiol levels was observed three weeks before vaginal delivery of term and premature infants; in both types of delivery, onset of labor was spontaneous. In contrast progesterone levels were only slightly decreased in these cases.     

Demonstration and evolution of chorionic gonadotropin in ewes]

Occurrence of ovine Chorionic Gonadotropin (oCG) is demonstrated in placenta and amniotic fluid with the use of a radioreceptor assay (corpus luteum membranes) in ewes. Identification of oCG is possible as early as 15th day of pregnancy. It should be secreted at a constant rate, and its maximum concentration is recorded on the 130th day. This hormonal factor might be one of the major components accountable for high progesteronemia observed during the 100 last days of pregnancy.     

Demonstration of lateral asymmetry in G-banded mouse embryo chromosomes

Summary Cells obtained from 10-day mouse embryos were cultured for 3 h in medium containing colcemid. Chromosome preparations were subjected to G-banding in either calcium-magnesium free Hank's solution or the ASG method. From one to several occurrences of lateral asymmetry (unequal banding of sister chromatids) were observed in the majority of karyotypes analyzed.Partial support for this study was provided by grant no. 2-PO1-ES00226-10, NIH, NIEHS and by a grant from the National Foundation-March of Dimes. We thank Don Driscoll for his capable assistance.     

Permeability of the isolated human amniotic membrane to divalent cations]

Membrane potential and resistance recordings, in vitro, show that Mg++ does not pass through the amnion from the inside of the amniotic compartment to the outside of the amniotic membrane. Mg++ may become fixed on the surface or in the midst of the amniotic membrane. However, Mg++ diffuses in the opposite direction. Ca++, Ba++, Sr++ diffuse in both directions across the amniotic membrane.     

Fehlerkorrekturen bei stereologischen Messungen an menschlichen Plazenten: 3. Der Holmes-Effekt

Summary In stereological measurings of volume and surface of human placental villi systematic over-estimation due to section thickness (Holmes-effect) was not observed, probably because it is compensated by overlapping of sections of villi.

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Arbeit mit Unterstützung durch die Deutsche Forschungsgemeinschaft.     

Extrapineal melatonin: sources,regulation, and potential functions

Endogenous melatonin is synthesized from tryptophan via 5-hydroxytryptamine. It is considered an indoleamine from a biochemical point of view because the melatonin molecule contains a substituted indolic ring with an amino group. The circadian production of melatonin by the pineal gland explains its chronobiotic influence on organismal activity, including the endocrine and non-endocrine rhythms. Other functions of melatonin, including its antioxidant and anti-inflammatory properties, its genomic effects, and its capacity to modulate mitochondrial homeostasis, are linked to the redox status of cells and tissues. With the aid of specific melatonin antibodies, the presence of melatonin has been detected in multiple extrapineal tissues including the brain, retina, lens, cochlea, Harderian gland, airway epithelium, skin, gastrointestinal tract, liver, kidney, thyroid, pancreas, thymus, spleen, immune system cells, carotid body, reproductive tract, and endothelial cells. In most of these tissues, the melatonin-synthesizing enzymes have been identified. Melatonin is present in essentially all biological fluids including cerebrospinal fluid, saliva, bile, synovial fluid, amniotic fluid, and breast milk. In several of these fluids, melatonin concentrations exceed those in the blood. The importance of the continual availability of melatonin at the cellular level is important for its physiological regulation of cell homeostasis, and may be relevant to its therapeutic applications. Because of this, it is essential to compile information related to its peripheral production and regulation of this ubiquitously acting indoleamine. Thus, this review emphasizes the presence of melatonin in extrapineal organs, tissues, and fluids of mammals including humans.     

Autoradiographic analysis of alanine uptake by newborn pig intestine

Summary All villus enterocytes in the newborn pig intestine take up alanine by a process which is largely Na-dependent. Uptake in the adult rabbit intestine is cinfined to enterocytes near the tips of villi. Previous conclusions about how transport changes during development are reviewed on the basis of these findings.     

Release of immuno-reactive and biologically active LH from fetal mouse pituitary in response to synthetic gonadotropin releasing factor (LRF)

Summary In an incubation system, LRF stimulated significantly the release of LH from 18-day-old mouse fetal pituitary. This LRF-induced LH release, measured by RIA in the incubation medium was able to increase the testosterone production by age-matched fetal testes. This data suggests that the hypothalamo-hypophyseal-testicular axis is functional at the end of mouse prenatal life.The expert technical assistance of MrsM. T. Latreille andA. L'Héritier are grafefully acknowledged.     

Demonstration of neuronal activities in primary cultures from fetal mouse hypothalamus maintained in a serum-free medium

Fetal neuronal cells dissociated from mouse hypothalamus are able to grow in a serum-free medium for two to four weeks. Several neuronal activities have been measured during the in vitro cell development. Whereas glutamic acid decarboxylase (EC 4.1.1.15) activity disappears, those of thyroliberin (TRH) and tyrosine hydroxylase (EC. 1.14.16.2) remain stable, and acetylcholine transferase one (EC 2.3.1.6) rises earlier than in a serum supplemented medium. These results show that primary cultures grown in serum-free medium offer a promising model for studying neuronal activity differentiation.     

Release of immuno-reactive and biologically active LH from fetal mouse pituitary in response to synthetic gonadotropin releasing factor (LRF).

In an incubation system, LRF stimulated significantly the release of LH from 18-day-old mouse fetal pituitary. This LRF-induced LH release, measured by RIA in the incubation medium was able to increase the testosterone production by age-matched fetal testes. This data suggests that the hypothalamo-hypophyseal-testicular axis is functional at the end of mouse prenatal life.     

Role of serum components in the binding and phagocytosis of oxidatively damaged erythrocytes by autologous mouse macrophages

To investigate the role of autologous serum components in the recognition of damaged cells by macrophages, we examined the binding and phagocytosis of damage oxidatively damaged red blood cells with Cu2+ and ascorbate (oxRBCs) by autologous resident mouse peritoneal macrophages. The binding of oxRBCs by macrophages was independent of the presence of serum. However, phagocytosis by macrophages increased with serum concentration, and macrophages showed little ingestion of oxRBCs in a serum-free medium. Macrophages neither bound nor appreciably ingested native RBCs (before oxidation) in either the absence or presence of autologous serum. Mouse macrophages ingested significantly more native as well as oxRBCs in the presence of heat-inactivated fetal calf serum than in the presence of heat-inactivated mouse serum. Pretreated oxRBCs with normal serum were rarely ingested by macrophages in a serum-free medium. Phagocytosis of oxRBCs was significantly inhibited by depletion of IgG or calcium from serum, by heat inactivation of complement, or by antiserum against mouse C3. These results demonstrate that serum components such as IgG, C3, and calcium are involved in phagocytosis of oxRBCs by autologous macrophages.     

Defining G protein-coupled receptor peptide ligand expressomes and signalomes in human and mouse islets

Introduction

Islets synthesise and secrete numerous peptides, some of which are known to be important regulators of islet function and glucose homeostasis. In this study, we quantified mRNAs encoding all peptide ligands of islet G protein-coupled receptors (GPCRs) in isolated human and mouse islets and carried out in vitro islet hormone secretion studies to provide functional confirmation for the species-specific role of peptide YY (PYY) in mouse islets.

Materials and methods

GPCR peptide ligand mRNAs in human and mouse islets were quantified by quantitative real-time PCR relative to the reference genes ACTB, GAPDH, PPIA, TBP and TFRC. The pathways connecting GPCR peptide ligands with their receptors were identified by manual searches in the PubMed, IUPHAR and Ingenuity databases. Distribution of PYY protein in mouse and human islets was determined by immunohistochemistry. Insulin, glucagon and somatostatin secretion from islets was measured by radioimmunoassay.

Results

We have quantified GPCR peptide ligand mRNA expression in human and mouse islets and created specific signalomes mapping the pathways by which islet peptide ligands regulate human and mouse GPCR signalling. We also identified species-specific islet expression of several GPCR ligands. In particular, PYY mRNA levels were ~ 40,000-fold higher in mouse than human islets, suggesting a more important role of locally secreted Pyy in mouse islets. This was confirmed by IHC and functional experiments measuring insulin, glucagon and somatostatin secretion.

Discussion

The detailed human and mouse islet GPCR peptide ligand atlases will allow accurate translation of mouse islet functional studies for the identification of GPCR/peptide signalling pathways relevant for human physiology, which may lead to novel treatment modalities of diabetes and metabolic disease.