The renal arterial pedicle in the human fetus

To analyze the incidence of renal arteries variations during the fetal period and compare these findings with previous findings in adults, we studied the renal arterial pedicle in 70 human fetuses ranging in age from 13 to 36 weeks postconception. The fetuses were injected through the right common carotid artery with a red polyester resin to fill in the arterial tree enabling the identification and dissection of the small fetal arteries. The renal arteries were analyzed considering their number, origin, direction and site of penetration. Among the 70 fetuses studied, 30 (42.8%) presented at least one kidney with renal artery variations. In 6 fetuses the variation was bilateral. Among the total of 140 renal pedicles studied, 36 presented arterial variations (25.7%). We did not find statistically significant difference between right and left kidneys and between male and female fetuses. In the present study we did find kidneys with more than 2 arteries, probably because we did not study kidneys with any kind of development anomaly. Even kidneys with malrotations of the vertical axis were removed from the study.     

Behavioral states in the human fetus

Simultaneous use of real-time ultrasonographic scanning and cardiotocography has demonstrated that the human fetus exhibits well-developed behavioral states from about 36 week's menstrual age onward. Four states have been identified that are very similar to states that have been described in neonates of equivalent age. Prior to 36 weeks, cycles are present in the state variables individually: however, these cycles are not synchronized. The implications of the alternation of behavioral states in the fetus for antepartum assessment of fetal condition are discussed.     

Synchrony in telomere length of the human fetus

We measured serum tumour necrosis factor-alpha (TNF-alpha) as well as interleukin-1betta (IL-1beta) and GH concentrations in 15 children with isolated growth hormone deficiency (GHD), age range 5.1-13.9 years, before and 4 and 24h after the first GH injection (0.1 IU/kg s.c.). No differences were found in basal concentrations of serum TNF-alpha and IL-1beta between GHD children (10.01 +/- 1.55 pg/ml and 2.14 +/- .16 ng/ml respectively) and sex- and age-matched controls (11.57 +/- 2.16 pg/ml and 3.78 +/- 1.46 ng/ml respectively). In GHD children, serum TNF-alpha and IL-1beta values had significantly increased (P < 0.002) 4h (26.75 +/- 5.57 pg/ml and 2.99 +/- 0.21 ng/ml respectively) and decreased again 24 h after GH administration. Likewise, serum GH levels had significantly increased 4 h (from 1.29 +/- 0.69 to 48.71 +/- 13.35 ng/ml, P < 0.001) and decreased to basal values 24h after GH administration. A significant correlation was found between basal serum concentrations of GH and those of both TNF-alpha (P < 0.01) and IL-1beta (P < 0.05). However, no correlation was found between serum GH concentration and either TNF-alpha or IL-1beta levels 4 and 24h after GH administration. Our data suggest that GH plays a role in modulating TNF-alpha and IL-1beta release in humans.     

Secretion and Sex differences in cord serum growth hormone levels of the human fetus (author's transl)

Cord venous growth hormone (GH) and somatostatin levels were measured by radioimmunoassay in 86 infants and 11 anencephalic infants. 1) Cord GH levels were 69.2 +/- 20.2 ng/ml (N = 6, gestational weeks (GW) : 21-30W, mean +/- S.D.), 31.5 +/- 24.3 ng/ml (N = 11, GW : 31-36W), and 17.6 +/- 8.9 ng/ml (N = 71, GW: 37-41). In anencephalic infants, cord GH levels were significantly lower (2.3 +/- 1.4 ng/ml) than those in preterm and fullterm infants. 2) In fullterm infants, cord GH levels of small infants (19.2 +/- 9.2 ng/ml, N = 33, birth weight less than 3,250g) were significantly higher than that of large infants (15.1 +/- 8.1 ng/ml, N = 38, birth weight greater than of equal too 3,250g). On the other hands, cord somatostatin levels were relatively lower in small infants than in large infants. 3) There was a significant difference between male cord GH levels (20.6 +/- 8.9 ng/ml, N = 35) and female cord GH levels (14.6 +/- 8.0 ng/ml, N = 36). These results suggest that fetal GH secretion is suppressed by GH inhibiting factor (somatotropin release inhibiting factor) from mid gestation toward term and there is a sex difference of fetal GH secretion in fullterm fetus.     

Ryanodine receptors and their role in genetic diseases (review)

The field of protein structure prediction is evolving rapidly and in the last few years a number of new methods have been developed and evaluated. However, comparative modeling, or modeling by homology, is still the method of choice when the unknown protein shares any significant sequence similarity with a protein of known structure. The accuracy of the method is highly dependent on the degree of similarity between the target protein and that used as a template. Nevertheless, careful consideration of all the steps performed in the modeling procedure allows useful information to be obtained also from a model based on very low sequence identity.     

Cerebral hemodynamics and oxygenation in the fetus. The role of intrapartum near-infrared spectroscopy

Current methods of intrapartum surveillance have made little impact on fetal mortality and morbidity while leading to increased caesarean section rates. Near-infrared spectroscopy is a powerful new technique that can continuously measure changes in fetal cerebral oxygenation and hemodynamics during labor. Data are presented suggest that near-infrared spectroscopy has potential as a new form of fetal monitoring. However, further technical developments and testing in clinical trials are necessary before its introduction into clinical practice.     

The role of melatonin and circadian phase in age-related sleep-maintenance insomnia: assessment in a clinical trial of melatonin replacement

The present investigation used a placebo-controlled, double-blind, crossover design to assess the sleep-promoting effect of three melatonin replacement delivery strategies in a group of patients with age-related sleep-maintenance insomnia. Subjects alternated between treatment and "washout" conditions in 2-week trials. The specific treatment strategies for a high physiological dose (0.5 mg) of melatonin were: (1) EARLY: An immediate-release dose taken 30 minutes before bedtime; (2) CONTINUOUS: A controlled-release dose taken 30 minutes before bedtime; (3) LATE: An immediate-release dose taken 4 hours after bedtime. The EARLY and LATE treatments yielded significant and unambiguous reductions in core body temperature. All three melatonin treatments shortened latencies to persistent sleep, demonstrating that high physiological doses of melatonin can promote sleep in this population. Despite this effect on sleep latency, however, melatonin was not effective in sustaining sleep. No treatment improved total sleep time, sleep efficiency, or wake after sleep onset. Likewise, melatonin did not improve subjective self-reports of nighttime sleep and daytime alertness. Correlational analyses comparing sleep in the placebo condition with melatonin production revealed that melatonin levels were not correlated with sleep. Furthermore, low melatonin producers were not preferentially responsive to melatonin replacement. Total sleep time and sleep efficiency were correlated with the timing of the endogenous melatonin rhythm, and particularly with the phase-relationship between habitual bedtime and the phase of the circadian timing system.     

Somatic genetic alterations in human malignant mesothelioma (review)

Rhodococcus sp. strain ECRD-1 was evaluated for its ability to desulfurize a 232 to 343 degrees C middle-distillate (diesel range) fraction of Oregon basin (OB) crude oil. OB oil was provided as the sole source of sulfur in batch cultures, and the extent of desulfurization and the chemical fate of the residual sulfur in the oil after treatment were determined. Gas chromatography (GC), flame ionization detection, and GC sulfur chemiluminesce detection analysis were used to qualitatively evaluate the effect of Rhodococcus sp. strain ECRD-1 treatment on the hydrocarbon and sulfur content of the oil, respectively. Total sulfur was determined by combustion of samples and measurement of released sulfur dioxide by infrared absorption. Up to 30% of the total sulfur in the middle distillate cut was removed, and compounds across the entire boiling range of the oil were affected. Sulfur K-edge X-ray absorption-edge spectroscopy was used to examine the chemical state of the sulfur remaining in the treated OB oil. Approximately equal amounts of thiophenic and sulfidic sulfur compounds were removed by ECRD-1 treatment, and over 50% of the sulfur remaining after treatment was in an oxidized form. The presence of partially oxidized sulfur compounds indicates that these compounds were en route to desulfurization. Overall, more than two-thirds of the sulfur had been removed or oxidized by the microbial treatment.     

Platelet mono-amine oxidase activity in the human fetus

Measurement of the platelet mono-amine oxidase (MAO) activity in the human fetus of 40 weeks gestation showed it to be equivalent to that found in the adult. The level represents a fully-developed mitochondrial MAO system in platelets and may reflect enzyme maturity in other tissues of the newborn.     

Differential expression of the melatonin receptor in human monocytes

Earlier studies have shown that the pineal hormone melatonin activates human monocytes. It is reported here that melatonin induces the secretion of IL-1, IL-6, and TNF in fresh and 1-day in vitro cultured monocytes that also express the melatonin receptor (Kd = 270 +/- 60 pM; 42,000-48,000 receptors/cell). However, when monocytes were cultured in vitro for 2 days, the number of receptors decreased to 11,000 receptors/cell, with the same Kd. LPS activation of fresh or 1-day cultured monocytes did not result in any increase in melatonin receptor number. LPS activation of 2-day cultured monocytes led to an increase in the number of melatonin receptors, from 11,000 receptors/cell to the plateau of 42,000 to 48,000 receptors/cell. The loss of receptors by 2-day cultured monocytes was not irreversible. Melatonin did not induce the release of IL-1, TNF, or IL-6 in monocytes cultured in vitro for 3 days and for up to 15 days, and these long time cultured monocytes did not express the melatonin receptors even after activation by LPS. The loss of melatonin receptors by monocytes cultured in vitro for 3 days and for up to 15 days was irreversible. Therefore, it is shown for the first time that human monocytes express melatonin receptors. Furthermore, human monocytes express melatonin receptors differentially depending on their state of maturation, and it appears that in vitro monocyte differentiation and maturation negatively affect human monocyte melatonin receptor expression.     

Exogenous melatonin fails to counteract the light-induced phase delay of human melatonin rhythm

HIV-1, subtype F was isolated from a seronegative child aged 2.5 yr. ELISA tests (Behring HIV-1 + 2, Abbott HIV-1 + 2, Wellcozyme HIV-1 Recombinant, Clonatec HIV-1 + 2, Genelavia Mixt), and also rapid tests (Abbott Pack, Serodia) were all negative, although some of them presented borderline reactivities. Western Blot (Cambridge Biotech) revealed an undetermined profile (traces of anti-gp160 plus anti-p24). A new WB test (Sanofi Dg. Pasteur) performed at a higher serum concentration (1/25) revealed a complete antibody profile, despite the very low intensity of bands. A new serum sample prelevated 6 month later was completely negative on all tests used. Both samples, were negatives in WB for HIV2 and HTLVs. A heparinised blood sample was used for the co-cultivation of PBMC and was proven to be positive in the 14th day of culture. The isolated DNA from end-culture cells was subjected to PCR amplifications for Heteroduplex Mobility Assay direct subtyping (primers ES7 and ES8) and for the investigation of genotypic sensitivity to AZT (primers A/NE1). Lymphocyte populations phenotyping revealed leukocytosis (> 15,000/mL) with a predominance of the CD8+ subset CD4/CD8 ratio was < 1. Plasmatic HIV-1 load (measured by bDNA--Chiron) did not reached detectable levels of HIV-1 RNA. p24 Ag assay (EIA-Coulter) revealed a detectable p24 antigenemia only in the first serum sample and only after acid dissociation. So, this patient may present an integrated HIV-1 infection until now "silent".     

Studies of melatonin effects on epithelia using the human embryonic kidney-293 (HEK-293) cell line

The expression of melatonin receptors (MR) of the Mel1a subtype in basolateral membrane of guinea pig kidney proximal tubule suggests that melatonin plays a role in regulating epithelial functions. To investigate the cellular basis of melatonin action on epithelia, we sought to establish an appropriate in vitro culture model. Epithelial cell lines originating from kidneys of dog (MDCK), pig (LLC-PK1), opossum (OK), and human embryo (HEK-293) were each tested for the presence of MR using 2-[125I]iodomelatonin (125I-MEL) as a radioligand. The HEK-293 cell line exhibited the highest specific 125I-MEL binding. By intermediate filament characterization, the HEK-293 cells were determined to be of epithelial origin. Binding of 125I-MEL in HEK-293 cells demonstrated saturability, reversibility, and high specificity with an equilibrium dissociation constant (Kd) value of 23.8 +/- 0.5 pM and a maximum number of binding sites (Bmax) value of 1.17 +/- 0.11 fmol/mg protein (n = 5), which are comparable with the reported Kd and Bmax values in human kidney cortex. Coincubation with GTPgammaS (10 microM) and pertussis toxin (100 ng/ml) provoked a marked decrease in binding affinity (Kd was increased by a factor of 1.5-2.0), with no significant difference in Bmax. Melatonin (1 microM) decreased the forskolin (10 microM) stimulated cAMP level by 50%. HEK-293 cells do not express dopamine D1A receptor. Following transient transfection of HEK-293 cells with human dopamine D1A receptor (hD1A-R), exposure of the cells to dopamine stimulated an increase in the level of cAMP. Similarly, transient transfection of HEK-293 cells with rat glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), and PTH type 1 receptors, each resulted in an hormone inducible increase in cAMP levels. Surprisingly, only the stimulatory effect of dopamine could be inhibited by exposure to melatonin. The inhibitory effect of melatonin on dopamine D1-induced increase in cAMP was completely inhibited by pertussis toxin (100 ng/ml, 18 h). Immunoblot and immunocytochemical studies were carried out using two polyclonal antibodies raised against the extra and cytoplasmic domains of Mel1a receptor. Immunoblot studies using antibody against the cytoplasmic domain of Mel1a receptor confirmed the presence of a peptide blockable 37 kDa band in HEK-293 cells. Indirect immunofluorescent studies with both antibodies revealed staining predominantly at the cell surface, but staining with the antibody directed against the cytoplasmic domain required prior cell permeabilization. By RT-PCR, HEK-293 cells express both Mel1a and Mel1b messenger RNAs, but the messenger RNA level for Mel1b is several orders of magnitude lower than for Mel1a. We conclude that HEK-293 cells express MR predominantly of the Mel1a subtype. Our evidence suggests that one of the ways that melatonin exerts its biological function is through modulation of cellular dopaminergic responses.     

The role of gap junctional intercellular communication (GJIC) disorders in experimental and human carcinogenesis

BACKGROUND: To evaluate the effect of plasminogen activator inhibitor type 1 (PAI-1) levels on the clearance of total tissue plasminogen activator (TPA) antigen, we studied the clearance of active TPA and TPA/PAI-1 complex in subjects with low (181+/-109 pmol/L; n=7) and high (1166+/-322 pmol/L; n=4) baseline active PAI-1. METHODS AND RESULTS: A 5-microg/kg bolus of TPA was infused over a 15-second period followed by measurement of TPA activity, TPA antigen, TPA/PAI-1, TPA/C1 inhibitor, PAI-1 activity, and PAI-1 antigen over a 4-hour period. alpha-Phase clearance of total TPA antigen was faster in subjects with low PAI-1 (t(1/2) of 3.5+/-0.7 minutes) versus high PAI-1 (t(1/2) of 5.3+/-0.9 minutes) (P=.006). Clearance of all factors was best fit by a two-compartment pharmacokinetic model based on a computer-simulated human circulatory system. The average hepatic clearance fraction in the two-compartment model was greater for active TPA (89+/-10%, t(1/2) of 2.4+/-0.3 minutes) than for TPA/PAI-1 complex (48+/-17%, t(1/2) of 5.0+/-1.8 minutes) (P=.0006). CONCLUSIONS: Plasma clearance of active TPA was faster than clearance of TPA/PAI-1 complex. High levels of active PAI-1 converted more TPA into TPA/PAI-1 complex, effectively slowing the clearance of total TPA antigen and explaining in part why high levels of PAI-1 activity are associated with increases in total TPA antigen.     

The action of the vaccinia virus upon placenta and fetus in revaccinated pregnants (author's transl)

We studied 608 antivariolic revaccinated pregnants in spring 1972 at different ages of gestation. 60 presented spontaneous abortus; in 502 cases there has been performed therapeutical abortion, and 46 pregnants revaccinated after 2 1/2-3 months of gestation continued their pregnancy. Pregnancy and birth in revaccinated pregnants which did not abort, evolved without any difference against the witness-sample; the newborns presented in a higher percentage underweight. The absence of the vaccinia-virus and of Guarnieri-inclusions in the examined placentae and embryos as well as the moment of abortion, only after 20 days from the revaccination data, leads to the supposition that the placental lesions do not seem to be produced by the direct action of the virus by its replication, but probably by reactions of hypersensibility of the late type against the alergizin antigens of the antismallpox vaccine. The antivariolic revaccination of the sample of pregnants, showed that the vaccinia virus did not present a malformative action upon the embryo, but in change the abortive action was manifest in indirect proportion to the age of gestation.     

Mitosis in the human embryo: the vital role of the sperm centrosome (centriole)

The pattern of sperm centrosomal (centriolar) inheritance, centrosomal replication and perpetuation during mitosis of the human embryo is reviewed with a series of electron micrographs. Embryonic cleavage involves repeated mitoses, a convenient sequence to study centriolar behaviour during cell division. After the paternal inheritance of centrioles in the human was reported (Sathananthan et al., 1991a), there has been an upsurge of centrosomal research in mammals, which largely follow the human pattern. The human egg has an inactive non-functional centrosome. The paternal centrosome contains a prominent centriole (proximal) associated with pericentriolar material which is transmitted to the embryo at fertilization and persists during sperm incorporation. Centriolar duplication occurs at the pronuclear stage (interphase) and the centrosome initially organizes a sperm aster when male and female pronuclei breakdown (prometaphase). The astral centrosome containing diplosomes (two typical centrioles) splits and relocates at opposite poles of a bipolar spindle to establish bipolarization, a prerequisite to normal cell division. Single or double centrioles occupy pivotal positions on spindle poles and paternal and maternal chromosomes organize on the equator of a metaphase spindle, at syngamy. Bipolarization occurs in all monospermic and in most dispermic ova. Dispermic embryos occasionally form two sperm asters initially and produce tripolar spindles (tripolarization). Anaphase and telophase follows producing two or three cells respectively, completing the first cell cycle. Descendants of the sperm centriole were found at every stage of perimplantation embryo development and were traced from fertilization through cleavage (first four cell cycles) to the morula and hatching blastocyst stage. Centrioles were associated with nuclei at interphase, when they were often replicating and occupied pivotal positions on spindle poles during mitosis. Sperm remnants were associated with centrioles and were found at most stages of cleavage. Centrioles were found in trophoblast, embryoblast and endoderm cells in hatching blastocysts. Pericentriolar, centrosomal material nucleated astral and spindle microtubules. Abnormal nuclear configurations observed in embryos reflect mitotic aberrations. The bovine embryo closely resembles the human embryo in centriolar behaviour during mitosis. It is concluded that the sperm centrosome is the functional active centrosome in humans and is likely the ancestor of centrioles within centrosomes in foetal and adult somatic cells. The role of the sperm centrosome in embryogenesis and male infertility is discussed, since it is of clinical importance in assisted reproduction.