Semi-Automatic GUI Platform to Characterize Brain Development in Preterm Children Using Ultrasound Images

The third trimester of pregnancy is the most critical period for human brain development, during which significant changes occur in the morphology of the brain. The development of sulci and gyri allows for a considerable increase in the brain surface. In preterm newborns, these changes occur in an extrauterine environment that may cause a disruption of the normal brain maturation process. We hypothesize that a normalized atlas of brain maturation with cerebral ultrasound images from birth to term equivalent age will help clinicians assess these changes. This work proposes a semi-automatic Graphical User Interface (GUI) platform for segmenting the main cerebral sulci in the clinical setting from ultrasound images. This platform has been obtained from images of a cerebral ultrasound neonatal database images provided by two clinical researchers from the Hospital Sant Joan de Déu in Barcelona, Spain. The primary objective is to provide a user-friendly design platform for clinicians for running and visualizing an atlas of images validated by medical experts. This GUI offers different segmentation approaches and pre-processing tools and is user-friendly and designed for running, visualizing images, and segmenting the principal sulci. The presented results are discussed in detail in this paper, providing an exhaustive analysis of the proposed approach's effectiveness.

Pitx2c deficiency confers cellular electrophysiological hallmarks of atrial fibrillation to isolated atrial myocytes

AIMS

Atrial fibrillation (AF) has been associated with altered expression of the transcription factor Pitx2c and a high incidence of calcium release-induced afterdepolarizations. However, the relationship between Pitx2c expression and defective calcium homeostasis remains unclear and we here aimed to determine how Pitx2c expression affects calcium release from the sarcoplasmic reticulum (SR) and its impact on electrical activity in isolated atrial myocytes.

METHODS

To address this issue, we applied confocal calcium imaging and patch-clamp techniques to atrial myocytes isolated from a mouse model with conditional atrial-specific deletion of Pitx2c.

RESULTS

Our findings demonstrate that heterozygous deletion of Pitx2c doubles the calcium spark frequency, increases the frequency of sparks/site 1.5-fold, the calcium spark decay constant from 36 to 42 ms and the wave frequency from none to 3.2 min^-1. Additionally, the cell capacitance increased by 30% and both the SR calcium load and the transient inward current (I_TI) frequency were doubled. Furthermore, the fraction of cells with spontaneous action potentials increased from none to 44%. These effects of Pitx2c deficiency were comparable in right and left atrial myocytes, and homozygous deletion of Pitx2c did not induce any further effects on sparks, SR calcium load, I_TI frequency or spontaneous action potentials.

CONCLUSION

Our findings demonstrate that heterozygous Pitx2c deletion induces defects in calcium homeostasis and electrical activity that mimic derangements observed in right atrial myocytes from patients with AF and suggest that Pitx2c deficiency confers cellular electrophysiological hallmarks of AF to isolated atrial myocytes.

An independent in-depth analysis proposing adjusted Global Initiative on Asthma (GINA) Step 1-2 treatment suggestions

The Global initiative on asthma (GINA) strategy included major changes for the treatment of mild asthma in the 2020 version, that are even taken to a next level in 2021, leaving a preferred track with only rescue therapy with inhaled corticosteroid and formoterol (ICS-FORM) for step 1-2 in 12+ years-old. It has been questioned how solid the evidence behind these recommendations is. We decided to independently conduct an in-depth analysis of published evidence based on a comprehensive evaluation of original articles and related appendices and publications, including quality of evidence and risk-of-bias per article. We first defined the major asthma treatment goals and proceeded to review how these were met in publications referenced in the main asthma guidelines. For patients with GINA 2021 Step 1 characteristics the analysis supports GINA's decision to avoid SABA monotherapy and to prefer ICS-FORM rescue with as alternative ICS rescue every time a SABA is used for ≥12 years, even though evidence is extrapolated from step 2 patients. For 6-11 year-olds we propose to consider ICS-FORM rescue as an alternative, as its use has been approved in this age-group, be it not as rescue-medication. For patients with GINA 2021 Step 2 characteristics our proposal slightly differs from GINA 2021. We propose to continue avoiding the separate use of SABA, using ICS rescue whenever a fast-acting bronchodilator is taken (even with ICS maintenance). Also, the superiority of ICS-FORM rescue over classical step 2 treatment is not uniform and year-long experience is lacking. Consequently for now, both treatment options seem equal: ICS-FORM rescue or ICS maintenance with SABA (+ICS) rescue. For 6-11 year-olds ICS rescue every time a SABA is used has the advantage of lower total ICS dose; as alternative we suggest ICS-FORM rescue. The best treatment option depends on patient characteristics and treatment goals. Recommendations should be reviewed as soon as new evidence becomes available.

Molecular transduction in receptor-ligand systems by planar electromagnetic fields

The coupling of a ligand with a molecular receptor induces a signal that travels through the receptor, reaching the internal domain and triggering a response cascade. In previous work on T-cell receptors and their coupling with foreign antigens, we observed the presence of planar molecular patterns able to generate electromagnetic fields within the proteins. These planes showed a coherent (synchronized) behavior, replicating immediately in the intracellular domain that which occurred in the extracellular domain as the ligand was coupled. In the present study, we examined this molecular transduction - the capacity of the coupling signal to penetrate deep inside the receptor molecule and induce a response. We verified the presence of synchronized behavior in diverse receptor-ligand systems. To appreciate this diversity, we present four biochemically different systems - TCR-peptide, calcium pump-ADP, haemoglobin-oxygen, and gp120-CD4 viral coupling. The confirmation of synchronized molecular transduction in each of these systems suggests that the proposed mechanism would occur in all biochemical receptor-ligand systems.

Influence of sex on intracellular calcium homeostasis in patients with atrial fibrillation

Aims

Atrial fibrillation (AF) has been associated with intracellular calcium disturbances in human atrial myocytes, but little is known about the potential influence of sex and we here aimed to address this issue.

Methods and results

Alterations in calcium regulatory mechanisms were assessed in human atrial myocytes from patients without AF or with long-standing persistent or permanent AF. Patch-clamp measurements revealed that L-type calcium current (I_Ca) density was significantly smaller in males with than without AF (−1.15 ± 0.37 vs. −2.06 ± 0.29 pA/pF) but not in females with AF (−1.88 ± 0.40 vs. −2.21 ± 0.0.30 pA/pF). In contrast, transient inward currents (I_Ti) were more frequent in females with than without AF (1.92 ± 0.36 vs. 1.10 ± 0.19 events/min) but not in males with AF. Moreover, confocal calcium imaging showed that females with AF had more calcium spark sites than those without AF (9.8 ± 1.8 vs. 2.2 ± 1.9 sites/µm²) and sparks were wider (3.0 ± 0.3 vs. 2.2 ± 0.3 µm) and lasted longer (79 ± 6 vs. 55 ± 8 ms), favouring their fusion into calcium waves that triggers I_TIs and afterdepolarizations. This was linked to higher ryanodine receptor phosphorylation at s2808 in women with AF, and inhibition of adenosine A_2A or beta-adrenergic receptors that modulate s2808 phosphorylation was able to reduce the higher incidence of I_TI in women with AF.

Conclusion

Perturbations of the calcium homoeostasis in AF is sex-dependent, concurring with increased spontaneous SR calcium release-induced electrical activity in women but not in men, and with diminished I_Ca density in men only.

Development of a 64 SNV panel for breed authentication in Iberian pigs and their derived meat products

Spanish legislation regulates the labelling of Iberian pig meat and dry-cured products, which are labelled as "Ibérico" or "100% Ibérico" when they come from Duroc x Iberian crossbred or Iberian purebred pigs. Although the analytical authentication of breed origin is not mandatory, a genetic diagnostic tool is demanded by producers and consumers. We have designed a 64 Single Nucleotide Variant genotyping panel displaying extreme allelic frequencies between Duroc and Iberian purebred samples. Average proportions of Iberian alleles of 0.99, 0.01, 0.77 and 0.48 were estimated by admixture clustering analysis of known origin samples, for Iberian and Duroc purebred, 75% Iberian and 50% Iberian classes, respectively. A supervised analysis with 1419 samples showed some overlapping between contiguous classes, but the calculated degrees of separability ranged from 0.800 to 0.996, exceeding the threshold value (0.70) for considering suitable for prediction. Therefore, this panel is a useful genetic tool to infer purebred or crossbred Iberian origin of live animals, meat and dry-cured products.

Dynamic and Irregular Distribution of RyR2 Clusters in the Periphery of Live Ventricular Myocytes

Cardiac ryanodine receptors (RyR2s) are Ca²⁺ release channels clustering in the sarcoplasmic reticulum membrane. These clusters are believed to be the elementary units of Ca²⁺ release. The distribution of these Ca²⁺ release units plays a critical role in determining the spatio-temporal profile and stability of sarcoplasmic reticulum Ca²⁺ release. RyR2 clusters located in the interior of cardiomyocytes are arranged in highly ordered arrays. However, little is known about the distribution and function of RyR2 clusters in the periphery of cardiomyocytes. Here, we used a knock-in mouse model expressing a green fluorescence protein (GFP)-tagged RyR2 to localize RyR2 clusters in live ventricular myocytes by virtue of their GFP fluorescence. Confocal imaging and total internal reflection fluorescence microscopy was employed to determine and compare the distribution of GFP-RyR2 in the interior and periphery of isolated live ventricular myocytes and in intact hearts. We found tightly ordered arrays of GFP-RyR2 clusters in the interior, as previously described. In contrast, irregular distribution of GFP-RyR2 clusters was observed in the periphery. Time-lapse total internal reflection fluorescence imaging revealed dynamic movements of GFP-RyR2 clusters in the periphery, which were affected by external Ca²⁺ and RyR2 activator (caffeine) and inhibitor (tetracaine), but little detectable movement of GFP-RyR2 clusters in the interior. Furthermore, simultaneous Ca²⁺- and GFP-imaging demonstrated that peripheral RyR2 clusters with an irregular distribution pattern are functional with a Ca²⁺ release profile similar to that in the interior. These results indicate that the distribution of RyR2 clusters in the periphery of live ventricular myocytes is irregular and dynamic, which is different from that of RyR2 clusters in the interior.

[Planar molecular arrangements aid the design of MHC class II binding peptides]

The coupling between peptides and MHC-II proteins in the human immune system is not well understood. This work presents an evidence-based hypothesis of a guiding intermolecular force present in every human MHC-II protein (HLA-II). Previously, we examined the spatial positions of the fully conserved residues in all HLA-II protein types. In each one, constant planar patterns were revealed. These molecular planes comprise of amino acid groups of the same chemical species (for example, Gly) distributed across the protein structure. Each amino acid plane has a unique direction and this directional element offers spatial selectivity. Constant within all planes, too, is the presence of an aromatic residue possessing electrons in movement, leading the authors to consider that the planes generate electromagnetic fields that could serve as an attractive force in a single direction. Selection and attraction between HLA-II molecules and antigen peptides would, therefore, be non-random, resulting in a coupling mechanism as effective and rapid as is clearly required in the immune response. On the basis of planar projections onto the HLA-II groove, modifications were made by substituting the key residues in the class II-associated invariant chain peptide-a peptide with a universal binding affinity-resulting in eight different modified peptides with affinities greater than that of the unmodified peptide. Accurate and reliable prediction of MHC class II-binding peptides may facilitate the design of universal vaccine-peptides with greatly enhanced binding affinities. The proposed mechanisms of selection, attraction and coupling between HLA-II and antigen peptides are explained further in the paper.

Spatial localization of ryanodine receptors in human cardiac cells

We present a novel image processing method to determine the location of ryanodine receptors in cardiac cells. A semi-automatic manual validation by an expert has been used in order to establish the performance of the segmentation method. The approach provides high accuracy under different experimental conditions and it is robust to common sources of noise including experimental, molecular and biological fluctuations.

Effects of dietary fat saturation on fatty acid composition and gene transcription in different tissues of Iberian pigs

The effect of two diets, respectively enriched with SFA (S) and PUFA (P), on FA tissue composition and gene expression was studied in fattened Iberian pigs. The FA composition of adipose, muscular and liver tissues was affected by dietary treatment. S group showed higher MUFA and MUFA/SFA ratio and lower PUFA and n-6/n-3 ratio than P group in all analyzed tissues. In muscle and liver the extracted lipids were separated into neutral lipids and polar lipid fractions which showed significantly different responses to the dietary treatment, especially in liver where no significant effect of diet was observed in NL fraction. The expression of six candidate genes related to lipogenesis and FA oxidation was analyzed by qPCR. In liver, stearoyl CoA desaturase (SCD), acetyl CoA carboxylase alpha (ACACA) and malic enzyme 1 (ME1) genes showed higher expression in S group. SCD, ACACA, ME1, and fatty acid synthase (FASN) gene expression levels showed a wide variation across the tested tissues, with much higher expression levels observed in adipose tissue than other tissues. Tissue FA profile and gene expression results support the deposition of dietary FA, the lipogenic effect of dietary saturated fat in liver and the employment of saturated dietary fat for endogenous synthesis of MUFA in all the analyzed tissues.

Dietary energy source largely affects tissue fatty acid composition but has minor influence on gene transcription in Iberian pigs

A trial was performed to compare the effects of different dietary sources of MUFA on the fatty acid (FA) composition, lipid metabolism, and gene transcription in different tissues of Iberian pigs. Twenty-seven Iberian male pigs of 28 kg live weight (LW) were divided in 2 groups and fed with 1 of 2 isocaloric diets: a standard diet with carbohydrates as energy source (CH) and a diet enriched with high-oleic sunflower oil (HO). Ham adipose tissue was sampled by biopsy at 44 and 70 kg LW. At 110 kg LW pigs were slaughtered and backfat, loin, and liver tissues were sampled. Animals of the HO group showed higher MUFA content and lower SFA in all the analyzed tissues (P < 0.001). These main effects were established early during the treatment and increased only slightly along time. Small diet effects were also detected on PUFA, which showed differences according to sampling time, tissue, and lipid fraction. Effects of diet on gene expression were explored with a combined approach analyzing adipose tissue transcriptome and quantifying the expression of a panel of key genes implicated in lipogenesis and lipid metabolism processes in backfat, muscle, and liver. Backfat transcriptome showed small effects of diet on gene expression, in number and magnitude. According to the posterior probabilities (PP) of the probe-specific expression differences between dietary groups (PP < 0.01), 37 genes were considered differentially expressed (DE). Gene ontology allowed relating them with several biological functions including lipid metabolic processes. Quantitative PCR confirmed several DE genes in adipose tissue (RXRG, LEP, and ME1; P < 0.0001, P < 0.05, and P < 0.0001, respectively), but no DE gene was found in loin or liver tissues. Joint results agree with a metabolic adjustment of adipose tissue FA levels by the subtle effect of the diet on the regulation of several lipid metabolism pathways, mainly FA oxidation and prostanoid synthesis, with LEP, RXRG, and PTGS2 genes playing mayor roles.

Measuring inbreeding and inbreeding depression on pig growth from pedigree or SNP-derived metrics

Multilocus homozygosity, measured as the proportion of the autosomal genome in homozygous genotypes or in runs of homozygosity, was compared with the respective pedigree inbreeding coefficients in 64 Iberian pigs genotyped using the Porcine SNP60 Beadchip. Pigs were sampled from a set of experimental animals with a large inbreeding variation born in a closed strain with a completely recorded multi-generation genealogy. Individual inbreeding coefficients calculated from pedigree were strongly correlated with the different SNP-derived metrics of homozygosity (r = 0.814-0.919). However, unequal correlations between molecular and pedigree inbreeding were observed at chromosomal level being mainly dependent on the number of SNPs and on the correlation between heterozygosities measured across different loci. A panel of 192 SNPs of intermediate frequencies was selected for genotyping 322 piglets to test inbreeding depression on postweaning growth performance (daily gain and weight at 90 days). The negative effects on these traits of homozygosities calculated from the genotypes of 168 quality-checked SNPs were similar to those of inbreeding coefficients. The results support that few hundreds of SNPs may be useful for measuring inbreeding and inbreeding depression, when the population structure or the mating system causes a large variance of inbreeding.

Detection, properties, and frequency of local calcium release from the sarcoplasmic reticulum in teleost cardiomyocytes

Calcium release from the sarcoplasmic reticulum (SR) plays a central role in the regulation of cardiac contraction and rhythm in mammals and humans but its role is controversial in teleosts. Since the zebrafish is an emerging model for studies of cardiovascular function and regeneration we here sought to determine if basic features of SR calcium release are phylogenetically conserved. Confocal calcium imaging was used to detect spontaneous calcium release (calcium sparks and waves) from the SR. Calcium sparks were detected in 16 of 38 trout atrial myocytes and 6 of 15 ventricular cells. The spark amplitude was 1.45±0.03 times the baseline fluorescence and the time to half maximal decay of sparks was 27±3 ms. Spark frequency was 0.88 sparks µm(-1) min(-1) while calcium waves were 8.5 times less frequent. Inhibition of SR calcium uptake reduced the calcium transient (F/F(0)) from 1.77±0.17 to 1.12±0.18 (p = 0.002) and abolished calcium sparks and waves. Moreover, elevation of extracellular calcium from 2 to 10 mM promoted early and delayed afterdepolarizations (from 0.6±0.3 min(-1) to 8.1±2.0 min(-1), p = 0.001), demonstrating the ability of SR calcium release to induce afterdepolarizations in the trout heart. Calcium sparks of similar width and duration were also observed in zebrafish ventricular myocytes. In conclusion, this is the first study to consistently report calcium sparks in teleosts and demonstrate that the basic features of calcium release through the ryanodine receptor are conserved, suggesting that teleost cardiac myocytes is a relevant model to study the functional impact of abnormal SR function.

Spatial channel interactions in cochlear implants

The modern multi-channel cochlear implant is widely considered to be the most successful neural prosthesis owing to its ability to restore partial hearing to post-lingually deafened adults and to allow essentially normal language development in pre-lingually deafened children. However, the implant performance varies greatly in individuals and is still limited in background noise, tonal language understanding, and music perception. One main cause for the individual variability and the limited performance in cochlear implants is spatial channel interaction from the stimulating electrodes to the auditory nerve and brain. Here we systematically examined spatial channel interactions at the physical, physiological, and perceptual levels in the same five modern cochlear implant subjects. The physical interaction was examined using an electric field imaging technique, which measured the voltage distribution as a function of the electrode position in the cochlea in response to the stimulation of a single electrode. The physiological interaction was examined by recording electrically evoked compound action potentials as a function of the electrode position in response to the stimulation of the same single electrode position. The perceptual interactions were characterized by changes in detection threshold as well as loudness summation in response to in-phase or out-of-phase dual-electrode stimulation. To minimize potentially confounding effects of temporal factors on spatial channel interactions, stimulus rates were limited to 100 Hz or less in all measurements. Several quantitative channel interaction indexes were developed to define and compare the width, slope and symmetry of the spatial excitation patterns derived from these physical, physiological and perceptual measures. The electric field imaging data revealed a broad but uniformly asymmetrical intracochlear electric field pattern, with the apical side producing a wider half-width and shallower slope than the basal side. In contrast, the evoked compound action potential and perceptual channel interaction data showed much greater individual variability. It is likely that actual reduction in neural and higher level interactions, instead of simple sharpening of the electric current field, would be the key to predicting and hopefully improving the variable cochlear implant performance. The present results are obtained with auditory prostheses but can be applied to other neural prostheses, in which independent spatial channels, rather than a high stimulation rate, are critical to their performance.

[Normal physiological variations of pubertal development: starting age of puberty, menarcheal age and size]

OBJECTIVES

To evaluate the impact of early, mid-onset, and late maturation, assessed by the age at menarche, height at the beginning of puberty, time of menarche, at one and two years after menarche in a group of healthy girls. The time lapse between the start of puberty and the advent of menarche was observed in that group of girls. To investigate whether their weight status (body mass index) is causally implicated in early start of puberty in these girls.

PATIENTS AND METHODS

A prospective observational study was performed on 266 healthy Caucasian girls, who were followed up with visits at the beginning of puberty, at menarche and then every six months. Physical examinations included height, weight and pubertal stages, and were assessed by clinical examination according to methods of Tanner. The statistical analysis was performed using the SPSS 12.0 package.

RESULTS

We found that mean age of breast development 2 (B2) was 10.72 years and mean menarcheal age was 12.43 years. The correlation coefficient (r) between the onset of puberty and its duration was r = -0.406 (p < 0.01), and that of age of pubertal onset versus age of menarche was r = 0.34 (p < 0.01). According to 25th and 80th percentiles, early matures were shorter at onset of puberty, at menarche and two years later. Post-menarcheal increase in stature was greatest in early maturers. There is also a correlation between the "z" score of body mass index and the age at onset of puberty (r = -0.398).

CONCLUSIONS

The puberty began at 10.72 years, the menarche appears at 12.43 as average. Girls who matured early were shorter at onset, at menarche and two years after, despite having greater peak height velocity and post-menarcheal increase in height. The age of menarche correlated with the "z" score of body mass index.

[Post-transplant diabetes mellitus depending on the pre-transplant dialysis technique]

Post-transplant diabetes mellitus (PTDM) is one of the most important complications in kidney transplant patients because it has a significant impact on graft and patient survival. Diagnosis of PTDM should be based on the American Diabetic Association criteria. Recent studies show the value of performing an oral glucose tolerance test in all patients. Multiple risk factors promote PTDM. PTDM incidence may be reduced by controlling modifiable factors (immunosuppression, obesity, infections...). According to RMRC data, patients on peritoneal dialysis are younger, but have a greater incidence rate of dyslipidemia and obesity. Recent data suggest that subclinical information, adiponectin, and ghrelin may be a significant pathogenetic factor in development of insulin resistance and diabetes mellitus. There is no clear evidence that the dialysis procedure influences the subclinical inflammatory state and adipocytokines. According to data from the Spanish group for the study of PTDM, a relationship exists between ghrelin levels and sex in patients on peritoneal dialysis. The most common metabolic complication in patients on peritoneal dialysis is hyperglycemia. Pre-transplant hyperglycemia promotes the occurrence of PTDM. There is no clear evidence in the literature showing that the dialysis procedure is a risk factor for the occurrence of PTDM. Additional multicenter studies are required to analyze the clinical and biological characteristics of renal patients and their relationship to PTDM.

Presence of Hypoderma lineatum stage I larvae in the esophagus of cattle slaughtered in Chihuahua, Chih., Mexico

In order to detect the presence of Hypoderma lineatum stage I larvae within the esophagus of cattle slaughtered in Chihuahua, Chihuahua, Mexico, a total of five samplings were carried out between July and November 2000. In each instance, a random sample was taken from 10% of the animals slaughtered in a single work shift in each of the two slaughterhouses included in this study. The esophagus were cut longitudinally in order to carry out visual inspection and detect the presence of H. lineatum stage I larvae in the submucosa. The larvae were separated and counted. We identified the presence of H. lineatum stage I larvae in the esophagus for all sampling dates, nevertheless, within the last sampling only one esophagus had them. For all sampling dates the prevalence ranged between 11 and 33%; the latter corresponded to the sampling in October. A total of 287 esophagus was inspected of which 54 were positive with one or more larvae (19%); 233 larvae were obtained from these cases. The number of larvae recovered per sampling ranged from 46 to 74 between July and October, the highest number was found in September's sampling. The largest amount of stage I larvae per esophagus was 22 in the months of July and August. Larvae were always located in the submucosa of the esophagus and all were oriented longitudinally.

Anisakid parasites of two forkbeards (Phycis blennoides and Phycis phycis) from the Mediterranean coasts of Andalucía (Southern Spain)

An epidemiological survey of anisakids was carried out on 209 specimens of greater forkbeard (Phycis blennoides) and 58 of forkbeard (Phycis phycis) captured off the Mediterranean coasts of Andalucía (southern Spain). Four species of nematodes were identified: Anisakis simplex s.l., Anisakis physeteris, Hysterothylacium aduncum and Hysterothylacium fabri. The total prevalence was 62.06% in the forkbeard and 58.85% in the greater forkbeard. The highest values of prevalence (56.90%), mean intensity (5.21) and mean abundance (2.96) were all obtained for H. fabri in the forkbeard. The most frequent parasite in the greater forkbeard was H. aduncum with 51.20% prevalence and values of 3.00 and 1.53 for mean intensity and mean abundance, respectively. The infestation parameters were also analyzed according to the host length, observing a maximum of parasitized fish (91.67%) in samples of P. blennoides longer than 40 cm, while in P. phycis, the highest prevalence (82.35%), conditioned by H. fabri parasitization, was found in fish with lengths between 30 and 35 cm.

Sharp-interface projection of a fluctuating phase-field model

We present a derivation of the sharp-interface limit of a generic fluctuating phase-field model for solidification. As a main result, we obtain a sharp-interface projection which presents noise terms in both the diffusion equation and in the moving boundary conditions. The presented procedure does not rely on the fluctuation-dissipation theorem, and can therefore be applied to account for both internal and external fluctuations in either variational or nonvariational phase-field formulations. In particular, it can be used to introduce thermodynamical fluctuations in nonvariational formulations of the phase-field model, which permit to reach better computational efficiency and provide more flexibility for describing some features of specific physical situations. This opens the possibility of performing quantitative phase-field simulations in crystal growth while accounting for the proper fluctuations of the system.

In vitro development of the fish parasite Hysterothylacium aduncum from the third larval stage recovered from a host to the third larval stage hatched from the egg

Anisakids are parasitic nematodes of fish worldwide, producing economic and human health concerns. It is thus important to ascertain their in vitro life cycle in laboratory studies. Here we describe the in vitro development of third-stage larvae (L3) of Hysterothylacium aduncum isolated from blue whiting Micromesistius poutassou, to the hatching of L3 from eggs obtained from H. aduncum worms grown in GLIT medium (a modified mixture of Yaeger's LIT [Liver Infusion Tryptose] and Grace's media) at pH 4.0, 13 degrees C and with 5% CO2 in air. Under these conditions, L3 recovered from fish developed to mature adults (3.4 to 6.2 cm in length), with oviposition starting from Day 26 in culture. Fertilized eggs (mean size 64 x 52 microm) had a thick, rugose eggshell and were larger than unfertilized ones (mean size 49 x 42 microm), whose eggshells were thin and smooth. Eggs laid during the first and second week of oviposition, and maintained in 2.8% NaCl solution at 13 degrees C, developed to L3. Under these maintenance conditions, between 20.6 and 52.5% of the eggs laid during the first week developed into larvae. Motile larvae, enclosed in a sheath, hatched from between 2 and 11% of these eggs. The larvae started to hatch 23 d after deposition. These larvae were 144 to 215 microm in length, enclosed in a 237 to 305 microm-long sheath. This GLIT culture medium may help to study the biology of this and other anisakids.

Subcellular localization of the voltage-dependent potassium channel Kv3.1b in postnatal and adult rat medial nucleus of the trapezoid body

A pre-embedding immunocytochemical method was used to study the subcellular distribution of the voltage-dependent potassium channel Kv3.1b in the medial nucleus of the trapezoid body (MNTB) in developing and adult rat. The main finding was the localization of the channel in specific membrane compartments of the calyces of Held and principal globular neurons. Thus, at postnatal day (P) 9 immunoparticles were densely localized in plasma membranes of globular cell bodies and their main dendrites. At P16, a strong Kv3.1b labeling was still observed in these globular cell compartments, but the most remarkable feature was the presence of immunoparticles in synaptic terminal membranes of the calyces of Held. However, the presynaptic and postsynaptic specializations of the calyx of Held-globular cell synapses were virtually devoid of immunoparticles. This same subcellular distribution of Kv3.1b was seen in adult, with membranes of calycine terminals more uniformly labeled. The developmental profile of Kv3.1b expression in MNTB coincides with the functional maturation of the calyx of Held-principal globular neuron synapse. The presence of the channel in this system is crucial for the high-frequency synaptic transmission of auditory signals.

In vitro cultivation of Hysterothylacium aduncum (Nematoda: Anisakidae) from 3rd-stage larvae to egg-laying adults

This is the first demonstration of the in vitro development of the 3rd-stage larvae (L3) of Hysterothylacium aduncum to the adult. This was achieved in a semi-defined medium that is easy to prepare and to reproduce. The L3, collected from the peritoneal cavity of horse mackerel (Trachurus trachurus), were individually inoculated into RPMI-1640 medium +20% heat-inactivated fetal bovine serum (IFBS). It has been demonstrated that the optimum temperature for development is around 13 degrees C and is stimulated by the presence of 5% CO2 in the growth atmosphere, increasing the percentage moulting to the 4th larval stage (L4) by 1.9-fold (from 44 to 82%) and the average survival of the nematodes by 1.6 times (from 60 to 96 days). When the larvae were grown at different pHs, optimum development occurred at pH 4.0. Under these conditions, all the larvae moulted to the L4 and more than two-thirds transformed to the adult stage--in which 25-30% of the females laid eggs--and reached an average survival of over 4 months. When this medium was supplemented with 1% (w/v) of commercial pepsin, all the larvae reached the adult stage, at least 45% of the females oviposited, laying around 12-fold more eggs per female than in the medium without pepsin. The mean size of the eggs (non-fertilized) obtained was 56.8 x 47.6 microm. The mean length of the adult males obtained was between 3.2 and 5.2 cm and the females were between 3.0 and 6.5 cm. The adult specimens were morphologically identified as Hysterothylacium aducum aduncum. This culture medium (RPMI-1640+20% (v/v) IFBS+1 commercial pepsin, at pH 4.0, 13 degrees C and 5% CO2 in air) could facilitate the identification of at least some of the larvae of the genus Hysterothylacium--and perhaps other anisakids--for which the specific identification and the biological study of these parasites is often difficult.

In vitro cultivation of anisakis simplex: pepsin increases survival and moulting from fourth larval to adult stage

This paper describes the in vitro cultivation of the 3rd-larval stage (L3) of Anisakis simplex to adulthood in a much simpler and easier to prepare medium than those described to date. The adult males obtained are between 3.8 and 6.5 cm long and the females between 4.5 and 8.0 cm. Some individually cultivated females laid eggs which had an average size of 44.4 x 50.5 microm. The culture conditions were as follows: medium RPMI-1640 supplemented with 20% heat-inactivated fetal bovine serum and 1% commercial pepsin, at pH 4.0 and a temperature of 37 degrees C, and in air atmosphere with 5% CO2. The pepsin was found to be the key to the success of the culture. The average survival of the worms in the culture increased from 50 to 88 days, due to the fact that the survival of the adults practically doubled (increasing by 1.9 times). Furthermore, the number of worms that completed the 4th moulting (M4) increased by 4.2 times, from 22.9 to 95.6%. This culture medium may facilitate, due to its simplicity, the study of anisakids, or at least of A. simplex, constituting another step towards achieving a complete in vitro life-cycle for these parasites.

Group II metabotropic glutamate receptors are differentially expressed in the medial nucleus of the trapezoid body in the developing and adult rat

The existence of a neuronal-glial signalling through the activation of neurotransmitter receptors expressed in glia is well-documented. In excitatory synapses, glutamate released from presynaptic terminals activates not only postsynaptic receptors, but also ionotropic and metabotropic glutamate receptors localized in the glia ensheathing the synapses. The medial nucleus of the trapezoid body of the auditory system is involved in the localization of sounds in the space. In this nucleus, the large excitatory synaptic terminals formed by the calyces of Held on the principal globular cell bodies are wrapped by astrocytic processes. Since these synapses are functional from early postnatal days, glia receiving excitatory synaptic signals from the calyces may participate in modulating the maturation and development of the system. Groups I and II of metabotropic glutamate receptors (mGluRs) have been localized in glial cells in different brain regions. To investigate whether group II mGluRs are present in the medial nucleus of the trapezoid body, we have studied the pattern of expression of mGluR2/3 in the developing and mature nucleus by means of immunocytochemichal methods. The most remarkable finding was the switch in the occurrence of mGluR2/3 from glial to neuronal compartments. Thus, a preferential localization of mGluR2/3 immunoreactivity was observed in astrocytic processes surrounding the calyces of Held during the early postnatal development. In contrast, the main feature in adult rats was the presence of the group II mGluRs in presynaptic calyces of Held and postsynaptic principal globular cells.From these observations we suggest a role for group II mGluRs in neuronal-glial signalling in the calyx of Held-principal globular neuron synapses. Activation of these receptors might be relevant to the maturation and modulation of synaptic transmission in the medial nucleus of the trapezoid body.

[Polycystic ovary syndrome: the importance of establishing diagnosis]

Polycystic ovary syndrome (PCOS) is a very common disorder that occurs up to 10% of premenopausal women. Although PCOS is known to be associated with a higher reproductive morbility and increased risk of hormone dependent-cancer, its diagnosis is particularly important because PCOS is strongly linked to insulin resistance. This involves a major risk of early metabolic and cardiovascular complications. On the other hand, the prevalence of metabolic disorders associated with insulin resistance is higher in family members of patients with PCOS than in those of normal women, which suggests that the treatment of this syndrome should be preventive rather than symptomatic. For that reason, PCOS might be considered a signal of a family disorder, a route to diabetes and a public health problem.

[Prevalence of metabolic disorders among family members of patients with polycystic ovary syndrome]

BACKGROUND

About 60% of patients with polycystic ovary syndrome (PCOS) have insulin resistance, predisposing them to the premature coronary disease and type 2-diabetes mellitus. However, the history of metabolic disorders in family members of patients with PCOS has been seldom documented in the literature.

AIM

To evaluate the family profile of metabolic disorders of PCOS patients and to determine their relative risk of developing one of them in comparison to a control group.

PATIENTS AND METHODS

Sixty PCOS patients were evaluated. The control group were 60 normal women. The data were obtained from the clinical history and personal interview with the patients, the controls and their relatives (brothers, parents and grandparents). The metabolic disorders considered were: dyslipidemia, obesity, hypertension and diabetes.

RESULTS

The ages were similar between groups (PCOS: 24.0 +/- 6.3; control group: 24.8 +/- 6.2 years). The prevalence of metabolic disorders was 62% in the relatives of the PCOS patients and 27.8% in the relatives of the control group (p < 0.005). The probability to develop a metabolic disorder within the family was 2.7 (2.2-3.3) fold higher in the PCOS group compared to the control group. The risk of developing hypertension, dyslipidemia, obesity and diabetes was 2.1 (1.5-2.9); 1.8 (1.5-2.7); 3.6 (2.6-4.9) and 2.7 (1.8-3.9), respectively, in the PCOS group compared to the control group.

CONCLUSIONS

The probability of finding a metabolic disorder in the families of PCOS patients, is 2.7 fold higher than in the control group families. The metabolic disorders are more frequent in parents and grandparents of the PCOS patients than in those of normal women.

Immunoreactivity for the group III metabotropic glutamate receptor subtype mGluR4a in the superficial laminae of the rat spinal dorsal horn

Studies indicate that metabotropic glutamate receptors (mGluRs) may play a role in spinal sensory transmission. We examined the cellular and subcellular distribution of the mGluR subtype 4a in spinal tissue by means of a specific antiserum and immunocytochemical techniques for light and electron microscopy. A dense plexus of mGluR4a-immunoreactive elements was seen in the dorsal horn, with an apparent accumulation in lamina II. The immunostaining was composed of sparse immunoreactive fibres and punctate elements. No perikaryal staining was seen. Immunostaining for mGluR4a was detected in small to medium-sized cells but not in large cells in dorsal root ganglia. At the electron microscopic level, superficial dorsal horn laminae demonstrated numerous immunoreactive vesicle-containing profiles. Labelling was present in the cytoplasmic matrix, but accretion of immunoreaction product to presynaptic specialisations was commonly observed. Axolemmal labelling was confirmed by using a preembedding immunogold technique, which revealed distinctive deposits of gold immunoparticles along presynaptic thickenings with an average centre-to-centre distance of 41 nm (41.145 +/- 13.59). Immunoreactive terminals often formed synaptic contacts with dendritic profiles immunonegative for mGluR4a. Immunonegative dendritic profiles were observed in apposition to both mGluR4a-immunoreactive and immunonegative terminals. Diffuse immunoperoxidase reaction product was also detected in dendritic profiles, some of which were contacted by mGluR4a-immunoreactive endings, but only occasionally were they observed to accumulate immunoreaction product along the postsynaptic density. Terminals immunoreactive for mGluR4a also formed axosomatic contacts. The present results reveal that mGluR4a subserves a complex spinal circuitry to which the primary afferent system seems to be a major contributor.

The metabotropic glutamate receptor subtype mGluR 2/3 is located at extrasynaptic loci in rat spinal dorsal horn synapses

The position of neurotransmitter receptors relative to active neurotransmitter release sites may be a major factor influencing neuronal responses. The location of the metabotropic glutamate receptor subtype mGluR2/3 was investigated in synaptic structures in the rat superficial spinal dorsal horn laminae by using a pre-embedding immunogold technique. Immunostaining for mGluR2/3 occurred in laminae I through III. Gold particles were encountered both in the cytosol and along the plasma membrane. Distinctive plasmalemmal immunodeposits were detected in vesicle-containing profiles, where they were located to membrane compartments distant from active release sites rather than in the close vicinity of synaptic specialisations. No distinct immunolabelling was observed in profiles meeting characteristics of primary afferent terminals. The extrasynaptic occurrence of mGluR2/3 suggests a presynaptic heteroreceptor role for these receptor subtypes in the spinal dorsal horn.

Immunolocalization of the mGluR1b splice variant of the metabotropic glutamate receptor 1 at parallel fiber-Purkinje cell synapses in the rat cerebellar cortex

Several metabotropic glutamate receptor (mGluR) subtypes have been identified in the cerebellar cortex that are targeted to different compartments in cerebellar cells. In this study, preembedding immunocytochemical methods for electron microscopy were used to investigate the subcellular distribution of the mGluR1b splice variant in the rat cerebellar cortex. Dendritic spines of Purkinje cells receiving parallel fiber synaptic terminals were immunoreactive for mGluR1b. With a preembedding immunogold method, approximately 25% of the mGluR1b immunolabeling was observed perisynaptically within 60 nm from the edge of the postsynaptic densities. Values of extrasynaptic gold particles beyond the first 60 nm were maintained at between 10 and 18% along the whole intracellular surface of the dendritic spine membranes of Purkinje cells. For comparison, the distribution of mGluR1a was studied. A predominant (approximately 37%) perisynaptic localization of mGluR1a was seen in dendritic spines of Purkinje cells, dropping the extrasynaptic labeling to 15% in the 60-120-nm bin from the edge of the postsynaptic specialization. Our results reveal that mGluR1b and mGluR1a are localized to the same subcellular compartments in Purkinje cells but that the densities of the perisynaptic and extrasynaptic pools were different for both isoforms. The compartmentalization of mGluR1b and mGluR1a might serve distinct requirements in cerebellar neurotransmission.

Immunocytochemical localization of the metabotropic glutamate receptor mGluR4a in the piriform cortex of the rat

This study evaluates the localization of the metabotropic glutamate receptor mGluR4a in the piriform cortex of rats using preembedding immunocytochemical methods. At the light microscopic level, punctate labeling was evident in layers Ia and Ib of the piriform cortex, and immunolabeled fibers were present in layers II and III. Following bilateral destruction of the olfactory bulb, the density of labeled puncta in layer Ia decreased. These results suggest that the receptor is present on the terminals of the lateral olfactory tract (LOT). Electron microscopic evaluation of layers Ia and Ib revealed that mGluR4a was localized in synaptic terminals in layers Ia and Ib. The terminals had clear, round synaptic vesicles and terminated on asymmetric synapses on dendritic spines and shafts. There was also immunolabeling of some dendritic profiles in layers Ia and Ib that were postsynaptic to unlabeled presynaptic terminals. These observations suggest that mGluR4a is present on presynaptic terminals in the layers of the piriform cortex that receive LOT and associational synapses. This is the same area in which previous studies have revealed the presence of mGluR7 and mGluR8, suggesting that all three receptors may be colocalized.

Distribution of the group II metabotropic glutamate receptors (mGluR2/3) in the enteric nervous system of the rat

We used affinity purified antisera specific for group II metabotropic glutamate receptors in combination with a pre-embedding immunocytochemical method for light microscopy to investigate the localization of mGluR2/3 receptors in the enteric nervous system of the rat small intestine. In the submucosal plexuses of the jejunum and ileum, strongly mGluR2/3 immunoreactive cells were distributed between the circular muscular layer and the muscularis mucosa. In addition, oval or rounded immunostained ganglion cells appeared located in the myenteric plexuses of both intestinal regions. Nerve fibers intensely stained were observed extending between adjacent myenteric ganglia. The localization of mGluR2/3 receptors in enteric neurons might have functional implications in the physiology and pathology of the gut.

Clustering of the group III metabotropic glutamate receptor 4a at parallel fiber synaptic terminals in the rat cerebellar molecular layer

We report in this study with a pre-embedding immunogold method, the clustering of the group III metabotropic glutamate receptor 4a (mGluR4a) along the presynaptic membrane of parallel fiber synaptic terminals in the cerebellar molecular layer. The mGluR4a clusters were homogeneously distributed and interspaced by about 60 nm. These results suggest a particular arrangement of mGluR4a which might help to a rapid and effective activation of this receptor by glutamate.

Developmental expression of the group III metabotropic glutamate receptor mGluR4a in the medial nucleus of the trapezoid body of the rat

A preembedding immunocytochemical method for light microscopy was used to study the postnatal development of expression of the group III metabotropic glutamate receptor mGluR4a in the medial nucleus of the trapezoid body (MNTB) of the rat. Immunoreactivity for mGluR4a was localized in axonal endings wrapping the principal globular neurons in MNTB, known as calyces of Held. The percentage of calyces of Held immunoreactive for mGluR4a increased progressively from postnatal day 3 (PND3), showing the highest density of labeled calyces by PND9. From this postnatal age on, a gradual reduction in the number of mGluR4a-immunopositive calyces of Held was observed, reaching the lowest level of labeled profiles in adult tissue. The developmental expression of mGluR4a in calyces of Held correlates well with previous studies in young animals showing a modulation of synaptic neurotransmission by group III mGluRs in these giant excitatory synapses made on MNTB principal neurons. All these observations together suggest that the expression of mGluR4a mainly between PND7 and PND12 might be relevant to the maturation and modulation of synaptic transmission at the calyces of Held.

Citric-acid cycle key enzyme activities during in vitro growth and metacyclogenesis of Leishmania infantum promastigotes

The activities of 5 key regulatory enzymes in most energetic systems, namely citrate synthase (EC 4.1.3.7, CS), NADP-specific isocitrate dehydrogenase (EC 1.1.1.42, ICDH), succinate dehydrogenase (EC 1.3.99.1, SDH), L-malate dehydrogenase (EC 1.1.1.37, MDH), and decarboxylating malic enzyme (EC 1.1.1.40, ME), were measured during the growth and metacyclogenesis of a cutaneous (CL) and a visceral (VL) strain of Leishmania infantum. As occurs with other Leishmania species, infective promastigotes were present along all phases of growth, but their percentages were higher at the early stationary phase for VL and the end of the same phase for CL. High CS and SDH activities were detected in both strains, as compared with other trypanosomatids, bringing more evidence for an actively functional citric-acid cycle in L. infantum. Both strains showed higher levels of CS, ICDH, and MDH and lower SDH and ME activities when more metacyclic promastigotes were present, but in VL these changes paralleled an increase in glucose consumption, whereas in CL these changes coincided with an NH3 hyperproduction. This suggests that the energy metabolism during L. infantum growth and metacyclogenesis is affected by regulated enzymes that probably respond to changes in the culture medium in the levels of glucose and amino acids.

Activity of key enzymes in glucose catabolism during the growth and metacyclogenesis of Leishmania infantum

This paper follows the development in the activity of the key enzymes of glycolysis and dehydrogenases of the pentose phosphate shunt throughout the in vitro growth and metacyclogenesis of two human strains of Leishmania infantum - one visceral (VL) and the other cutaneous (CL) - together with changes in the glucose, ammonium, and proton concentrations in the culture medium. In the first stage, ammonium was generated and no glucose was consumed. Later on, all the glucose was consumed and, finally, ammonium was generated again. The ammonium concentration increased 16- and 21-fold in cultures of VL and CL strains, respectively. The activities of the glycosomal enzymes hexokinase and phosphofructokinase differed in each strain, always being higher in CL than in VL and increasing throughout the culture period in CL while decreasing in VL. This probably indicates a different capability to adapt to the culture medium conditions. The activities of the pentose phosphate shunt enzymes examined indicate that 6-phosphogluconate dehydrogenase is possibly a rate-limiting enzyme for this pathway. Pyruvate kinase is a cytosolic control enzyme of glycolysis in trypanosomatids, and its activity decreased throughout the growth and differentiation of both strains of L. infantum, as occurs in other trypanosomatids. It was also observed that glucose catabolism was more active in the cutaneous strain than in the visceral one.

Investigations on the in vitro metacyclogenesis of a visceral and a cutaneous human strain of Leishmania infantum

The in vitro metacyclogenesis of a visceral (VL) and cutaneous (CL) human strain of Leishmania infantum was monitored in order to find out the kinetics of this process and the in vitro infective capacity for macrophages of the metacyclic promastigotes developed. To identify, enumerate, and separate the metacyclic population, the complement-dependent lysis by normal serum and the agglutination by peanut agglutinin (PNA) were used, as they were shown to be useful for the purpose of this study. Maximum percentage of metacyclics was detected by both techniques on the 4th day of growth for VL and the 6th day for CL, and was higher for the VL strain. The in vitro infectivity for macrophages of two strains was assayed, and the high parasitization data obtained were transformed in order to determine the increase of the parasite burden for macrophages throughout the incubation time of the experiments (2-72 h post-infection (p.i.)). This parameter is denominated the infectivity ratio (%I) and calculated as follows: (number of intracellular parasites per infected macrophage at 'x' time p.i./number of intracellular parasites per infected macrophage at 2 h p.i.) x 100. When %I was calculated for promastigotes unagglutinated by PNA (PNA-)--metacyclic or infective promastigotes--at any time of culture, the %I at 72 h p.i. was always much higher than for agglutinated promastigotes (2.1-12.5 times)--non-infective promastigotes--and unfractionated promastigotes from culture (1.7-9.5 times), especially with VL parasites. Likewise, the %I for VL PNA- promastigotes from the 4th day of culture was 1.9 times higher than for CL PNA- promastigotes from the 6th day of culture. The higher resistance to lysis by serum, percentage of metacyclics (PNA-), and infectivity ratio of VL than CL could be related to a higher spreading capability into the host body associated with higher pathogenic effects of the visceral strain than the cutaneous one.

Glutamate-like immunoreactivity in ascending spinofugal afferents to the rat periaqueductal grey

The midbrain periaqueductal gray is a key structure for the mediation of an integrated defence behaviour. Although a prominent role for glutamate in PAG mechanisms is supported by both behavioural and morphological studies, whether PAG afferents conveying somatosensory information constitute a source of glutamatergic input to the PAG remains unknown. Here, we have compared the projection pattern of orthogradely-labelled spinoannular fibres with the distribution of glutamate-like immunoreactivity in the PAG at the light microscopic level. Transaxonal labelling was observed throughout the whole rostrocaudal axis of the PAG except for the dorsolateral regions. Cell-processes and terminal-reminiscent puncta were strongly immunoreactive in all PAG regions, including the dorsolateral areas. To ascertain whether glutamate-immunoreactive puncta observed at light microscopy indeed constituted axon terminals of the spinoannular system, glutamate-like immunoreactivity was assessed in orthogradely-labelled synaptic terminals using a post-embedding immunogold procedure for electron microscopy. Quantitative analysis of gold particle densities revealed over twice as strong an immunoreactivity in anatomically-identified spinoannular axon terminals as in dendrites postsynaptic to them, perikarya and inhibitory Gray II synapses, as well as an over 5-fold heavier immunolabelling than in glial profiles. These findings reveal that glutamate is accumulated in synaptic terminals of the spinoannular system, supporting a neurotransmitter role for this acidic amino acid in spinofugal afferents to the PAG.

Immunocytochemical localization of the mGluR1b metabotropic glutamate receptor in the rat hypothalamus

The mGluR1 metabotropic glutamate receptor is a G-protein-coupled receptor that exists as different C-terminal splice variants. When expressed in mammalian cells, the mGluR1 splice variants exhibit diverse transduction mechanisms and also slightly differ in their apparent agonist affinities. In the present study, we used an affinity-purified antiserum, specifically reactive to the mGluRlb splice variant, in combination with a highly sensitive preembedding immunocytochemical method for light microscopy to investigate the distribution of this receptor in the rat hypothalamus. An intense immunoreactivity for mGluRlb was observed in distinct hypothalamic nuclei. Thus, neuronal cell bodies and dendrites were stained in the preoptic area, suprachiasmatic nucleus, dorsal hypothalamus, lateral hypothalamus, dorsomedial nucleus, tuberomammilary nucleus, and lateral mammilary body. The ventromedial nucleus exhibited neuropil immunostaining but neuronal cell bodies were not labeled. Strong mGluRlb immunoreactivity was observed in magnocellular neurons of the neuroendocrine supraoptic, paraventricular, and arcuate nuclei. Also, neuronal cell bodies were heavily labeled in the retrochiasmatic nucleus, anterior commissural nucleus, and periventricular nucleus. These immunocytochemical observations, together with previous studies, suggest that mGluRlb is coexpressed with other class I mGluRs in some nuclei throughout the hypothalamus. However, mGluRlb is so far the only receptor of this class strongly expressed in the supraoptic, paraventricular, and arcuate nuclei, which might have relevant implications in the physiological control of the neuroendocrine hypothalamic-pituitary system.

[Molecular genetic study of a severe growth hormone deficiency in a Chilean family]

The first and so far the only form of isolated growth hormone deficiency to accede to molecular genetic analysis is IGHD 1A, which has an autosomal recessive mode of inheritance. Several sizes of growth hormone gene deletions, ranging from 6.7 to 8.5 Kb are responsible for IGHD 1A. It has been reported that children with IGHD 1A have an initial good response to growth hormone treatment, followed by growth failure associated with the development of blocking antibodies against growth hormone. The effectiveness of treatment has been associated to the size of the gene deletion. We performed a molecular genetic analysis of the growth hormone locus, using Southern Blot and PCR techniques, to a 12 years old girl who fulfilled the criteria for IGHD 1A and her closer relatives. The results showed a 7 Kb deletion for the growth hormone gene in the girl and one of her brothers.

[Cigarette smoking and its relation to pregnancy and lactation in Arica (Chile)]

Cigarette smoker and non smoker mothers from Africa, Chile, were followed along pregnancy and lactation and the influence of cigarette smoking on infant's birth weight and length of lactation was assessed from a sample of 240 pregnant women, 87 (36.3%) of them were actively smoking mothers and 33 among these (37.9%) smoked throughout all pregnancy and lactation. Mothers who smoked along lactation showed significantly shorter exclusive breast feeding time (2.6 month) in comparison with non smokers (3.5 month, p < 0.05) and their total lactation time was also reduced (4.2 vs. 5.3 months respectively, p < 0.01).