Developmental hematopoiesis

Hematopoiesis is a developmental process that evolves throughout the lifespan of an individual. Most work in the field has focused on events occurring in the adult bone marrow (BM). In the embryo, blood and endothelial cell generation begins very early after gastrulation, in defined intraembryonic mesodermic sites. Recent multidisciplinary studies, taking advantage of classic embryological and gene targeting technology in various species, have provided a new image of embryofetal lymphohemopoiesis, which includes the suggestion of developmental compartmentalization or waves. The first hematopoietic stem cells (HSC) migrate further and home in an ordered sequence of supporting microenvironments depending on scarcely known molecular requirements. These early hematopoietic progenitors show important differences in their cell biology and differentiation potentialities with respect to those present in adult stages; this fact, together with specific microenvironmental influences, define a process that diverges significantly from that occurring in the BM. Here, we update the latest developments in the field, the new understanding of lymphohemopoiesis in prenatal life, and the novel questions that this emerging paradigm is producing.

Hygiene behaviour in rural Nicaragua in relation to diarrhoea

BACKGROUND

Childhood diarrhoea is a leading cause of morbidity and mortality in Nicaragua. Amongst the risk factors for its transmission are 'poor' hygiene practices. We investigated the effect of a large number of hygiene practices on diarrhoeal disease in children aged <2 years and validated the technique of direct observation of hygiene behaviour.

METHODS

A prospective follow-up study was carried out in a rural zone of Nicaragua. From the database of a previously conducted case-control study on water and sanitation 172 families were recruited, half of which had experienced a higher than expected rate of diarrhoea in their children and the other half a lower rate. Hygiene behaviour was observed over two mornings and diarrhoea incidence was recorded with a calendar, filled out by the mother, and collected every week for 5 months.

RESULTS

Of 46 'good' practices studied, 39 were associated with a lower risk of diarrhoea, five were unrelated and only for two a higher risk was observed. Washing of hands, domestic cleanliness (kitchen, living room, yard) and the use of a diaper/underclothes by the child had the strongest protective effect. Schooling (>3 years of primary school) and better economic position (possession of a radio) had a positive influence on general hygiene behaviour, education having a slightly stronger effect when a radio was present. Individual hygiene behaviour appeared to be highly variable in contrast with the consistent behaviour of the community as a whole. Feasible and appropriate indicators of hygiene behaviour were found to be domestic cleanliness and the use of a diaper or underclothes by the child.

CONCLUSION

A consistent relationship between almost all hygiene practices and diarrhoea was detected, more schooling producing better hygiene behaviour. The high variability of hygiene behaviour at the individual level requires repeated observations (at least two) before and after the hygiene education in the event one wants to measure the impact of the campaign on the individual.

Use of intrauterine contraceptive devices in nulliparous women: personal experience over a 12-year period

OBJECTIVE

To evaluate the use of intrauterine contraceptive devices (IUDs) in nulliparous women compared to their use in parous women.

METHODS

A comparative cross-sectional study was carried out to determine the reasons for removal of IUDs inserted between 1985 and 1996 in a sample of 227 nulliparous women and 2080 parous women. The statistical analysis was performed using the chi 2 test; the differences were considered to be significant when p < 0.05.

RESULTS

The reasons for removal of IUDs in the two groups were: expiry, 49.1% in the nulliparous group vs. 48.2% in the parous group; planned pregnancy, 21.7% vs. 15.4%; accidental pregnancy, 4.8% vs. 6.3%; expulsion, 1.6% vs. 5.1%; pelvic inflammatory disease, 1.6% vs. 1.1%; pain and/or bleeding, 14.5% vs. 10.2%; other, 6.4% vs. 6.3%; vasectomy or tubal sterilization, 0% vs. 7%.

CONCLUSION

Our data suggest that nulliparity is not a contraindication for the use of an IUD, and that the use of an IUD in nulliparous women is as safe and effective as in parous women.

Lack of HLA-G soluble isoforms in Graves-Basedow thyrocytes and complete cDNA sequence of the HLA-G*01012 allele

The presence of HLA-G mRNA has been studied in thyroid follicular cells from autoimmune patients with Graves' disease. Investigating the possible role of the expression of the HLA-G gene in tissue inflammation, we have found four of the six HLA-G mRNA isoforms described: G1, G2, G3 and G4, but not the soluble ones G5 and G6. Soluble G isoforms may be responsible for inducing tolerance and inflammation control and their absence in autoimmune thyroid follicular cells may induce failure of such control. In addition, the complete coding sequence of HLA-G*01012 has been obtained from thyrocytes and it shows only four synonymous changes with respect to the HLA-G*01011 allele; this further supports the existence of an evolutionary pressure for invariance on HLA-G genes.

Gonadotropin-releasing hormone increases ability of the spermatozoa to bind to the human zona pellucida

Sperm-zona pellucida binding, a crucial step in the process of fertilization, takes place in vivo in the upper portion of the fallopian tube. The presence of GnRH-like peptides in the female and the male genital tract has been described. In this work, the effect of GnRH and related peptides upon sperm-zona pellucida binding ability was studied. Sperm aliquots, capacitated for 4.5 h, were incubated for 5 min with saline (control) or 20 nM of GnRH, C-terminal (1-5) or N-terminal (5-10) fragments of GnRH, Substance P, dynorphin, bombesin, or mixed GnRH (a synthetic peptide with the same amino acids as GnRH but in different order). Sperm were also incubated with the GnRH antagonist Ac-3,4-dehydro-Pro1, -p-fluoro-<FONT SIZE=-1>D-Phe2, <FONT SIZE=-1>D-Trp3,6-LHRH, alone or before adding GnRH. The sperm were then tested using the hemizona assay. After 10 min, the number of zona-bound sperm was determined. In addition, the effect of GnRH upon the acrosome reactions, sperm movement characteristics, and sperm-zona collisions was evaluated. Sperm treated with GnRH bound in higher numbers to the zona than did control sperm (p < 0.005). The GnRH fragments, the GnRH antagonist, and related peptides did not have any effect on sperm-zona interaction; however, the GnRH antagonist totally blocked the stimulatory effect of GnRH. GnRH did not affect the percentage of acrosome-reacted sperm, pattern of sperm movement, or frequency of sperm-zona collisions. I suggest that the increased ability of the sperm to bind to the zona may be due to exposure and/or change of affinity of zona receptors on the sperm plasma membrane.

[Sudden death due to recuperated ventricular fibrillation: Brugada syndrome?]

We report a 47 years old male who was recuperated from a sudden death, and in whom the cardiological assessment showed a right bundle branch block and a fluctuating ST segment elevation V1 to V3. During the electrophysiological study, a polymorphic tachycardia and a ventricular fibrillation were induced. Procainamide administration enhanced ST segment alterations in right precordial leads, and isoproterenol normalized the EKG. All these disturbances are similar to the condition described by Brugada brothers. The patient was treated with an internal implantable defibrillator, without the use of antiarrhythmic drugs and is well after four months of follow up.

[Implantable defibrillators in the management of malignant ventricular tachyarrhythmias. Experience at the Arrhythmia National Center]

BACKGROUND

Implantable defibrillators are the most effective means to prevent sudden death in patients with malignant ventricular tachyarrhythmias. The availability of this type of devices is limited in Chile, due to their high price.

AIM

To report the first patients treated with implantable defibrillators in our hospital.

PATIENTS AND METHODS

Nine males and one female aged 13 to 65 years old are reported. Three presented with ventricular fibrillation (presenting out of the hospital in three) and the rest had ventricular tachycardia resistant to drugs or radiofrequency ablation.

RESULTS

All implants were performed using intracardiac electrodes. The generator was implanted in the pectoral region in nine and in the abdomen in one. A successful defibrillation was obtained with less than 15 J in four patients, with 20 J in three and with 24 J in three. There were no complications during the procedure. After a 12 months follow up, four patients have been treated by the implantable device. One of these subjects had a ventricular fibrillation in two occasions. One patient died of a bronchopneumonia two years after the implant.

CONCLUSIONS

Implantable defibrillators are an effective therapy for the treatment of malignant ventricular arrhythmias with a high risk of sudden death.

Transcription and weak expression of HLA-DRB6: a gene with anomalies in exon 1 and other regions

HLA-DRB6 is one of the human major histocompatibility complex (MHC) genes present in DR1, DR2, and DR10 haplotypes (approximately 26% of individuals). It shows several anomalies in human and non-human primates, including exon 2 stop codons (non-randomly grouped between codons 74 and 94) and a promoter region, and an exon 1 coming from an inserted retrovirus. It has been shown that not only chimpanzee but also human Mhc-DRB6 lack the usual 3' untranslated (UT) polyadenylation signal, and in the present work it was found that the human DRB6 gene coming from an HLA-DR2 haplotype is effectively transcribed after transfection in mouse L cells, and that HLA-DRB6 molecules may be expressed on the cell surface. DRB6 transcription level is remarkably lower in human than in chimpanzee. Moreover, their exons 1 (both taken from the 3'LTR region of a mammary tumor retrovirus) are also different; this shows that these viral insertions may be an important mechanism for different evolutionary changes in orthologous genes of different species. The pathways by which DRB6 molecules may be expressed on the membrane are unclear but other examples of truncated protein expression have also been described, even within the human major histocompatibility complex (i. e., in HLA-G). Finally, the presence of mature HLA-DRB6 mRNA molecules supports the notion that splicing may take place even in the absence of a canonical 3'UT polyadenylation signal.

Effect of dexamethasone therapy on the neonatal ductus arteriosus

Patent ductus arteriosus (PDA) is believed to be a contributing factor in the etiopathogenesis of bronchopulmonary dysplasia (BPD). We studied the effects of early dexamethasone therapy on persistent ductal patency and the role of PDA in the etiopathogenesis of BPD during the course of a randomized double-blind trial of dexamethasone to prevent BPD. Infants, who weighed between 700 and 999 g, had severe RDS, and had been given surfactant, were randomized to receive a 12-day course of dexamethasone (n = 13) or placebo (n = 17) starting within the first 12 hours of postnatal life. The diagnosis of PDA was made clinically and was confirmed by cardiac ultrasound. The incidence of clinically significant ductus in infants who weighed less than 1000 g was 23% in the dexamethasone-treated group, as compared with 59% in infants who were given placebo. This difference was marginally significant, p = 0.05, odds ratio 0.21, 95% confidence interval 0.04-1.05. None of the infants in the dexamethasone group had recurrence of PDA after indomethacin therapy as compared with three infants in the placebo group. Dexamethasone significantly reduced the number of days infants required ventilator and supplemental oxygen as compared with infants who received placebo. Dexamethasone, as compared with placebo, also reduced the incidence of BPD, p = 0.025, odds ratio 0.08, 95% confidence interval 0.01-0.58. Dexamethasone may reduce the incidence of PDA in premature infants who weigh less than 1000 g at birth and thereby reduce the incidence of BPD.

[Low energy transcatheter atrial defibrillation in one patient with refractory atrial fibrillation]

Most cases of atrial fibrillation are converted with antiarrhythmic medications or external electric defibrillation. However, in some refractory patients, an internal transcatheter defibrillation must be attempted. We report a 50 years old male with an atrial fibrillation of one year duration that was refractory to pharmacological treatment and in whom external cardioversion was unsuccessful. After the application of a bifasic shock of 10 joules between a catheter in the right atrium and another one located at the coronary sinus, the patient was converted to sinus rhythm. At two months of follow up, the patient continues in sinus rhythm.

Protective Effect of Broccoli, Onion, Carrot, and Licorice Extracts against Cytotoxicity of N-Nitrosamines Evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium Bromide Assay

The protective effect of nine fruit and vegetable aqueous (H(2)O) and ethanolic (EtOH) extracts against the cytotoxicity of N-nitrosodimethylamine (NDMA), N-nitrosopyrrolidine (NPYR), N-nitrosodibutylamine (NDBA), and N-nitrosopiperidine (NPIP) was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The fruit extracts under investigation did not show a protective effect against any N-nitrosamines tested. Four vegetable extracts exhibited a protective effect (to 100% of survival) and a stimulation of cellular proliferation (>100% of survival) in decreasing order against NDMA and NPYR: broccoli(EtOH) > onion(H2O) > carrot(EtOH) > onion(EtOH) > licorice(H2O). Decreasing orders against NDBA and NPIP were, respectively, broccoli(EtOH) > licorice(H2O) > carrot(EtOH) > onion(EtOH) and broccoli(EtOH) > carrot(EtOH) > licorice(H2O) > onion(EtOH). Thus, broccoli(EtOH) extract (19-20 mg/mL) showed greater protective effect and stimulation of cellular proliferation (160% of survival) against all N-nitrosamines studied than the other vegetable extracts tested.

Mhc-E polymorphism in Pongidae primates: the same allele is found in two different species

Mhc-E intron 1, exon 2, intron 2, and exon 3 from pygmy chimpanzee (Pan paniscus), chimpanzee (Pan troglodytes), gorilla (Gorilla gorilla) and orangutan (Pongo pygmaeus) have been sequenced; six new Mhc-E alleles have been obtained but sequence changes are only placed either in introns or in synonymous exonic bases. One pygmy chimpanzee Mhc-E DNA sequence is identical to another sequence from chimpanzee; the fact that no variation is found also at the intronic level suggests that these two species of chimpanzee may have recently separated and/or that both of them might only represent subspecies. Mhc-E phylogenetic trees separate two evolutionary groups: Pongidae, including humans, and Cercopithecinae; this is also found by studying another non-classical class I gene, Mhc-G. The Mhc-E alleles' invariance at the protein level supports that strong selective forces are operating at the Mhc-E locus, as has also been found in both Cercopithecinae and humans. These allelic and evolutionary data suggest an altogether different functionality for HLA-E (and also HLA-G) compared with classical class I proteins: i.e., sending negative (tolerogenic) signals to NK and T cells.

Nontraumatic bilateral diaphragmatic myopathy: an unusual disturbance

Bilateral diaphragmatic paralysis (BDP) is an uncommon entity among neuromuscular diseases. We present a young female with no triggering factors who developed progressive dyspnea with respiratory failure. Further studies led to the diagnosis of BDP.

Interleukin-1beta does not increase synaptic inhibition in hippocampal CA3 pyramidal and dentate gyrus granule cells of the rat in vitro

Effects of interleukin-1beta (bath-applied; 500 pM) on rat hippocampal CA3 pyramidal and dentate granule cells were studied using intracellular microelectrode recording in vitro. In both cell types membrane input resistance, resting membrane potential and action potential amplitude remained stable throughout. No change was seen in postsynaptic potentials in granule cells. After blocking excitatory synaptic transmission in CA3 pyramids interleukin-1beta was found to consistently decrease synaptic inhibition by about 30%.

Inhibition of follicular growth by two different oral contraceptives (monophasic and triphasic) containing ethinylestradiol and gestodene

OBJECTIVE

To evaluate the inhibition level of ovarian follicular growth produced by a triphasic oral contraceptive (OC) containing ethinylestradiol and gestodene vs. the level produced by a monophasic OC containing the same components.

METHODS

A randomized, blind, cross-over trial was performed in a sample of 56 women. The follicular diameters were measured in 56 cycles under triphasic contraceptive treatment, and the other 56 under monophasic contraceptive treatment, using vaginal ultrasound. The statistical analysis was performed using the Student's t test.

RESULTS

The mean follicular diameter under monophasic OC treatment was found to be 8.16 mm (standard deviation 4.5), and while under triphasic OC treatment was found to be 7.44 mm (standard deviation 2.8) (p > 0.05). In 17 out of 112 cycles (15%), a certain degree of follicular activity was found (follicular diameter more than 10 mm), 10 cycles under monophasic OC and 7 cycles under triphasic OC.

CONCLUSIONS

The triphasic OC provides good inhibition of follicular growth and excellent contraceptive efficacy.

[Maximum static respiratory pressures in adults. The reference values for a Mediterranean Caucasian population]

The aim of this study was to establish reference values for PImax and PEmax for the Mediterranean adult population. Male and female individuals between 18 and 83 years old meeting the criteria for consideration as references and residing in the metropolitan area of Valencia were assigned by decades to six subgroups, each containing at least 20 men and 20 women. PEmax was obtained from the point of maximum expiration (residual volume) and PImax was the point of maximum inspiration (total lung capacity). The cohort, which finally included 264 subjects (129 men and 135 women), was separated a priori by sex for data analysis. The following types of variables were studied: sociological (employment, educational level and exercise), biometric (age, height and weight) and spirometric results. A linear correlation analysis was performed for each pair of variables and a Kolmogorov-Smirnov test of normality was performed. In order to check the accuracy of PImax and PEmax readings, intra-individual variability was determined by performing three consecutive procedures over 3 days in 39 randomly selected individuals (18 men and 21 women). Significant inter-day and inter-test effects for respiratory pressures were thus ruled out. Predictive equations were worked out using a simple linear model including all predictive variables and eliminating weaker variables in a stepwise manner. Mathematical goodness of fit was assessed by a coefficient for multiple determinations (R2); also determined were the estimated standard error and statistical significance. We also compared observed and estimated values and the behavior of residual values in terms of their independence, normality and homoscedasticity. Reference limits were established by defining percentiles. The equations finally arrived at for men were as follows: PImax (-cmH2O) - 1.03 x Age + 0.59 x Weight + 133.07, PEmax (cmH2O) - 1.31 x Age + 263.12. The equations for women were PImax (-cmH2O) - 0.64 x Age + 125.18, PEmax (cmH2O) - 0.57 x Age + 0.65 x Weight + 116.26. Agreement with the usual references (the Black and Hyatt equations) was analyzed.

[Long-term effects of nasal continuous positive airway pressure on ventilatory patterns of patients with obstructive sleep apnea syndrome]

We studied 20 patients with obstructive sleep apnea syndrome (OSAS) prospectively, before and after administering continuous positive airway pressure through a nasal mask (CPAPn) at night for 10 months, with the aim of determining the effects of ventilatory pattern of long-term treatment with CPAPn in OSAS patients. The following data were collected for all patients: anthropometric variables, lung function test results, arterial gasometric readings at rest, oxygen alveolar-arterial differential [Dif(A-a)O2)], central respiratory function variables at rest and during hypercapnic stimulus. Mean duration (range) of treatment with CPAPn was 12.5 (10-18) months. We observed a significant increase in PaO2 (p = 0.01) and a decrease in PaCO2 (p = 0.02) with slight variations in body weight and no changes in lung mechanics or in Dif(A-a)O2. The ventilatory pattern at rest showed an increased in VE and in respiratory frequency (p = 0.0003 and p = 0.033, respectively) with non significant changes in VT. The VT/Ti ratio increased (p = 0.015) and P0.1 decreased slightly (p = 0.025). We found no significant changes in the CO2 response slopes of VE or P0.1. In conclusion, CPAPn improves hypoxemia and hypercapnia in OSAS patients, above all by increasing baseline basal ventilation. The exact mechanisms implicated are poorly understood, but our data suggest a certain direct or indirect effect on respiratory muscles, reducing muscle fatigue, thus favoring greater availability during sleep.

[Primary pulmonary hypertension: treatment with prostacyclin before lung transplantation]

We report our experience with two patients diagnosed of primary pulmonary hypertension who later received lung transplants, with treatment with short-acting pulmonary vasodilators (epoprostenol) provided as a bridge to transplantation. Continuous intravenous perfusion at a dose of 6 ng/kg/min was provided to the first patient, a 19-year-old man, for 26 days. An initial dose of 4 ng/kg/min followed by 6 ng/kg/min was given to the second patient, a 49-year-old woman, for 6 months. Symptoms were drastically reduced in both patients, significantly improving their quality of life.

A competitive enzyme-linked immunosorbent assay for detection of bovine milk in ovine and caprine milk and cheese using a monoclonal antibody against bovine beta-casein

A competitive ELISA (enzyme-linked immunosorbent assay) was performed to detect and quantify bovine milk in ovine and caprine milk and cheese using a monoclonal antibody (AH4 MAb) against bovine beta-casein. Ovine or caprine milk and cheese containing bovine milk were added simultaneously with the AH4 MAb to the wells of a microtiter plate that had been previously sensitized with commercial bovine beta-casein. The bovine caseins in milk or cheese samples compete with the bovine beta-casein bound to the plate for the AH4 MAb binding sites. Further immunorecognition of AH4 MAb bound to the bovine beta-casein immobilized onto the plate was attained with rabbit anti-mouse immunoglobulin conjugated to peroxidase. Subsequent enzymic conversion of the substrate showed clear differences in absorbance values during assay of mixtures of ovine and caprine milk and cheese containing various amounts of bovine milk. The competitive ELISA developed in this work allows the quantitative detection of bovine milk in ovine and caprine milk and cheese samples in the range of 0.5 to 25% of substitution.

Virulence factors-pathogenicity relationships for Aeromonas species from clinical and food isolates

The presence of virulence factors in 96 Aeromonas strains isolated from food and clinical samples was studied. Neither cytotoxic activity and hydrophobicity, not the presence of pili or an extra surface layer made it possible to establish differences between food and clinical strains. Statistical studies showed that cytotoxin production was associated with a positive Voges-Proskauer reaction, inability to ferment arabinose and a positive lysine decarboxylation. Therefore, when comparing cytotoxic clinical and food strains with lysine decarboxylation phenotype, there was a significant difference (p < 0.05) between the two groups. The association of a cytotoxin production and lysine decarboxylation character should thus be considered as a possible virulence marker.

Allelic diversity at the primate Mhc-G locus: exon 3 bears stop codons in all Cercopithecinae sequences

Twenty-seven major histocompatibility complex (Mhc)-G exon 2, exon 3, and exon 2 and 3 allelic sequences were obtained together with 12 different intron 2 sequences. Homo sapiens, Pan troglodytes, Pan paniscus, Gorilla gorilla, Pongo pygmaeus, Macaca fascicularis, Macaca mulatta, and Cercopithecus aethiops individuals were studied. Polymorphism does not follow the classical pattern of three hypervariable regions per domain and is found in all species studied; exon 3 (equivalent to the alpha 2 protein domain) shows stop codons in the Cercopithecinae group but not in the Pongidae and human groups. Dendrograms show that cotton top tamarin (Saguinus oedipus) Mhc-G sequences are closer to Homo sapiens and Pongidae than to Cercopithecinae, probably due to the stop codons existing at exon 3 of the latter. There is a clear trans-species evolution of allelism in Cercopithecinae and also in exon 2 of all the other apes studied, but a generation of allelism within each species may be present on exon 3 sequences. This discrepancy may be due to the preferential use of exon 2 over exon 3 at the mRNA splicing level within each species in order to obtain the appropriate functional G product. Mhc-G intron 2 shows conserved motifs in all species studied, particularly a 23 base pair deletion between positions 161 and 183 which is locus specific, and some of the invariant residues, important for peptide presentation, conserved in classical class I molecules from fish and reptiles to humans were not found in Mhc-G alleles; the intron 2 dendrogram also shows a particular pattern of allelism within each species. In summary, Mhc-G has substantial differences from other classical class I genes: polymorphism patterns, tissue distribution, gene structure, splicing variability, and probably an allelism variability within each species at exon 3. The G proteins may also be different. This indicates that the Mhc-G function may not be peptide presentation to the clonotypic T-cell receptor.

Interaction of human spermatozoa with the zona pellucida of oocyte: development of the acrosome reaction

Mammalian spermatozoa are not able to fertilize an oocyte upon ejaculation. To gain fertilizing ability, spermatozoa must, either in vivo or in vitro, undergo a process termed capacitation. Since a reliable marker for capacitation does not exist, it is considered that this process is completed when the spermatozoa are able to undergo acrosomal x intestinal mucosa which might require tandem signaling events for this process is the presence of a vascular countercurrent arrangement in the subepithelial compartment. As happens for absorbed solutes, this countercurrent phenomenon may distort transepithelial solute gradient. For example, perfusion of mammalian intestinal loops in vivo with solutions containing fMLP was previously found to induce neutrophil attachment to endothelial cells and structurally defined endothelial activation, but failed to elicit directed migration across the lamina propria (Madara, unpublished observations), suggesting that directed migration may require a more stable gradient than that afforded by the usual soluble signals. For example, once present in inflamed tissue, IL-8 is likely to retain its biological activity for several hours, as shown by local intradermal administration in animals and humans. In contrast to Il-8, chemokines such as fMLP or LTB4 are degraded rapidly by oxidation or hydrolysis. Fertilization is a very complex phenomenon, involving sequential interactions between the fertilizing spermatozoon and cumulus oophorus, ZP, and oolemma. The AR may be playing a key role in penetration of spermatozoa through these egg vestments.

[Isolated hepatic transplant in patient with cystic fibrosis]

Cystic fibrosis (CF) is a recessive autosomic disease with multiorgan, although predominantly pancreatic and pulmonary, involvement. Liver involvement is infrequent in children under the age of 5 years, but increases progressively with time. It is characterized by the development of focal biliary cirrhosis with eventual appearance of portal hypertension. During the last few years the more effective control of the pulmonary complications, which are the main cause of mortality, has led to an increase in the survival of these patients and thus the number of patients with CF and liver involvement is greater every day. In these cases, the prognosis is bad and most patients die in 4 to 5 years. Isolated liver transplantation is a recently proposed alternative for patients who have developed liver cirrhosis but who maintain acceptable pulmonary function. The case of a 14-years-old patient in whom liver transplantation was performed with good results after 8 months of follow-up is presented. Improvement in the nutritive state and pulmonary function was observed.

A controlled trial of dexamethasone to prevent bronchopulmonary dysplasia in surfactant-treated infants

BACKGROUND

Surfactant therapy now has a well-established role in the treatment of neonates with respiratory distress syndrome but has failed to reduce the incidence of bronchopulmonary dysplasia (BPD). We conducted a double-blind, placebo-controlled trial to test the hypothesis that dexamethasone therapy given during the first 12 days of life to very low birth weight infants would be synergistic to surfactant in preventing BPD.

METHODS

Seventy surfactant-pretreated infants (700-1500 g) who had severe respiratory distress syndrome (a/A ratio, 0.18 +/- 0.10; mean airway pressure, 11.1 +/- 1.9 cm H2O; fraction of inspired oxygen, 0.81 +/- 0.22) were enrolled to receive a 12-day course of dexamethasone (n = 36) or saline placebo (n = 34) starting within the first 12 hours after birth. The starting dose of dexamethasone was 0.5 mg/kg per day, and it was tapered progressively.

RESULTS

Ventilator variables at 5 to 14 days were significantly improved in those infants who received dexamethasone compared with those who received the placebo. The effect seem to be more marked in infants weighting less than 1250 g at birth. Significantly more infants could be extubated by 14 days of age in the dexamethasone group (26 of 32 vs 14 of 32). Dexamethasone therapy reduced the incidence of BPD at 28 days (odds ratio, 0.1; 95% confidence interval, 0.03 to 0.3) and eliminated BPD at 36 weeks' postconceptional age. Dexamethasone-treated infants had greater weight loss at 14 days (12.9 +/- 6.4% vs 3.7 +/- 8.6%, respectively) and higher blood pressures from days 3 to 10. However, no differences were seen in time to regain birth weight, hypertension (1 infant in each group), or incidence of intraventricular hemorrhage.

CONCLUSIONS

We found an additive effect between dexamethasone and surfactant in improving pulmonary status and reducing the incidence of BPD. Compared with the placebo, dexamethasone therapy was more effective in reducing the incidence of BPD in surfactant-pretreated very low birth weight infants.

Sperm interaction with human oviductal cells in vitro

In this article we describe the in-vitro interaction between human spermatozoa and oviductal epithelial cell monolayers. Freshly obtained spermatozoa were added to culture dishes containing human oviductal cells (co-culture), culture medium (control) or culture medium which had previously been used for culture of oviductal cells (conditioned medium). At 0, 5, 24, and 48 h of incubation the percentage of motile spermatozoa was determined and their motion characteristics analysed. Aliquots were taken to determine the percentage of acrosome-reacted spermatozoa. The spermatozoa were motile for a longer period in the presence of oviductal cells (54 +/- 9% co-culture versus 18 +/- 3% control, at 48 h) and the kinetics of the acrosome reaction exhibited a different pattern. In the control the percentage of reacted spermatozoa increased progressively throughout incubation. In co-culture, there was an increase only at 5 h; thereafter, the percentage of acrosome reactions did not change. Spermatozoa incubated in conditioned medium exhibited a behaviour halfway between the control and the co-culture. The pattern of sperm movement was not different in any of the experimental conditions. Although there was no binding between spermatozoa and oviductal epithelial cells, the frequency of the ciliary beat increased after spermatozoa were added to the oviductal cell monolayers. These results suggest that incubation with oviductal cells increases sperm survival, stabilizes the acrosome, and modifies the frequency of ciliary beat.

Assays of the biological activities of two fatty acid derivatives formed in the edible mushrooms cantharellus cibarius and C. tubaeformis as a response to injury

Cibaric acid (1) and 10-hydroxy-8-decenoic acid (2) are two fatty acid derivatives that are formed in the fruit bodies of Cantharellus cibarius (chanterelle) and C. tubaeformis as a response to injury. Unlike the potent defensive sesquiterpenes formed in injured fruit bodies of the pungent Lactarius species, compounds 1 and 2 only possess very weak antimicrobial and cytotoxic activity. Compound 2 was found to be a very weak direct-acting mutagen in the Ames test (<1 revertant/microgram and plate), while cibaric acid (1) was inactive in this assay. As 1 is destroyed during cooking, there are currently no reasons for suspecting that the consumption of C. cibarius poses a risk to consumers.

Polyclonal antibodies against protein F from the cell envelope of Pseudomonas fluorescens for the detection of psychrotrophic bacteria in refrigerated meat using an indirect ELISA

An indirect enzyme-linked immunosorbent assay (ELISA) has been developed for detection of Pseudomonas fluorescens and related psychrotrophic bacteria in refrigerated meat. The ELISA uses polyclonal antibodies raised in rabbits against protein F from the cell envelope of Pseudomonas fluorescens AH-70. The anti-protein F antibodies were recovered from the crude antiserum by ammonium sulfate precipitation and conjugated to biotin. Commercial Extr Avidin-peroxidase conjugate was used to detect the biotinylated antibodies bound to their specific antigens. Subsequent enzymatic conversion of substrate gave distinct absorbance differences when assaying meat samples containing P. fluorescens strains of different origin as well as related psychrotrophic microorganisms. The detection threshold for the ELISA assay developed in this work was 10(4)-10(5) cfu cm(-2).

[Anesthetic complications in sequential bipulmonary transplantation in patients with cystic fibrosis. Apropos of 6 cases]

Cystic fibrosis (CF) is a disease characterized mainly by altered exocrine gland function that eventually produces irreversible dysfunction of the pancreas and lungs. The respiratory insufficiency that develops in CF patients in the advanced stages of disease can only be corrected at this time by lung or heart-lung transplantation. We describe our experience with 6 terminal phase CF patients who underwent sequential double lung transplantation (SDLT). Anesthesia was intravenous, with exhaustive hemodynamic and respiratory monitoring. During surgery the most frequently encountered hemodynamic complications were low minute volume, arterial hypotension and irregular heart rate. The main respiratory complications were hypoxemia, hypercapnia and pulmonary edema of the implanted lung, which developed in all cases to varying degrees related to the organ's state of preservation and duration of ischemia. Other complications were the need for extracorporeal circulation in 1 case, oliguria and blood loss requiring multiple transfusions. The most critical moments were at the time of clamping the pulmonary artery, the period after revascularization of the donated lung, and at the start of patient ventilation through the first implanted lung so that the second could be implanted. Although our series is small, it is of interest given the limited Spanish experience with lung transplantation in CF patients, and the good early results obtained, which are similar to those reported for other diseases.

Epidemic outbreak of interstitial lung disease in aerographics textile workers--the "Ardystil syndrome": a first year follow up

BACKGROUND

The longer term respiratory effects of massive inhalational exposure of textile printing sprayers to Acramin (the "Ardystil syndrome") are not well established.

METHODS

A 12 month follow up of 27 heavily exposed textile sprayers was performed.

RESULTS

Twenty one patients experienced cough, 18 dyspnoea, and 17 nose bleeding at initial exposure, with histological evidence of organising pneumonia in 13 cases, radiological abnormalities detected by computed tomographic scanning in 20 cases, and diminution of diffusion capacity to below 80% of predicted in seven cases. At one year after exposure symptoms persisted in 15 cases, radiological alterations in six, and diffusion capacity was reduced in nine.

CONCLUSIONS

Whilst most of our patients showed improvement at one year, evidence of persistent lung involvement was present in an appreciable minority of exposed cases.

Evaluation of intercostal cryoanalgesia versus conventional analgesia in postthoracotomy pain

The objective of the study was to evaluate the effects of cryoanalgesia in patients undergoing posterolateral thoracotomy. A double-blind randomized and prospective study was performed in 100 patients undergoing thoracotomy. They were randomized into two groups: Group A, 55 patients, who had undergone an intercostal cryoanalgesia and group B, control, 45 patients treated only with pharmacological analgesia ad libitum. In both groups we assessed pain in the first 7 postsurgical days, the amount of analgesia required, electromyography of the intercostal muscles involved and recording of maximal static respiratory pressures. Postsurgical pain was significantly lower (p < 0.001) in group A. No patient in group A needed major analgesia and the amount of aminopyrines required was significantly lower (p < 0.001) than those used in group B. Maximal static inspiratory pressure (PImax) showed no significant changes and no significant differences were found between the two groups. Maximal static expiratory pressure (PEmax) significantly decreased (p < 0.001) in the 1st and 2nd week and it was not related to the type of analgesia used. We advocate the use of cryoanalgesia since it significantly reduces pain as well as the doses of analgesia.

HLA DR and DQ polymorphism in Ashkenazi and non-Ashkenazi Jews: comparison with other Mediterraneans

HLA-DR and DQ alleles have been detected by DNA typing in Ashkenazi and non-Ashkenazi Jews from Israel. Allele frequencies, characteristic DR/DQ linkage disequilibria, population distances and their corresponding dendrogram by using the Neighbor-Joining method were used to study relatedness between Jewish and other Mediterranean and non Mediterranean populations. Closest relatedness is observed between Ashkenazi and non-Ashkenazi Jews, and, in decreasing order, also with Algerians, Spaniards (including Spanish-Basques), French and Italians. Also, particular characteristic Central European alleles are observed in Ashkenazi Jews and Mediterranean/African alleles in non-Ashkenazi Jews. This is consistent with historical data, Jews being an ancient Mediterranean population, who have had a certain degree of admixture with their 2000-3000 years old neighbors in spite of cultural and religious traditions which have preserved identity outside Israel.

Epidermoid carcinoma of the hand: report of a case

The case of a 71 year old man who presented with an advanced epidermoid carcinoma of the dorsum of the hand, is reported. The patient was treated with radiotherapy as an alternative to amputation. Irradiation consisted of a combination of Co-60 photons and 6 Mev electrons. The cosmetic and functional results were excellent and the patient has been free of hand tumor for two and one-half years.

Purification and characterization of an arabinofuranosidase from Bacillus polymyxa expressed in Bacillus subtilis

Two polypeptides showing alpha-L-arabinofuranosidase activity have been purified to homogeneity from culture supernatants of a Bacillus subtilis clone harbouring the xynD gene [Gosalbes et al. (1991) J Bacteriol 173: 7705-7710] from Bacillus polymyxa. Both polypeptides, with determined molecular masses of 64 kDa and 53 kDa, share the same sequence at their N termini, which also coincides with the sequence deduced for the mature protein from the previously determined sequence of nucleotides (Gosalbes et al. 1991). The two polypeptides have been biochemically characterized. Arabinose is the unique product released from arabinose-containing xylans which are substrates for both enzyme forms. Other natural arabinose-containing polysaccharides, such as arabinogalactans, are not attacked by them but some artificial arabinose derivatives are good substrates for both polypeptides. Their arabinose-releasing activity on arabinoxylans facilitates the hydrolysis of the xylan backbone by some endoxylanases from Bacillus polymyxa.

Effect of cyclosporin on lung diffusing capacity in renal transplant patients

A prospective lung function study pre- and postrenal transplantation was performed on 21 patients in order to evaluate whether cyclosporin decreased the lung diffusing capacity due to lung toxicity. Initial inclusion criteria were absence of respiratory symptoms and normal findings in both chest X-ray and pulmonary function tests. Participants had to be nonsmokers. We determined spirometry including lung volumes, arterial blood gases, carbon monoxide diffusing capacity by the single breath method (DLCOSB), and rate of CO uptake per unit of lung volume (KCO) before and 3, 6, and 12 months after transplantation. Immunosuppression consisted of prednisone and cyclosporin, maintaining total blood levels between 100 and 250 ng/ml. Spirometric and blood gases data remained within reference levels during the follow-up. Hemoglobin (Hb) pretransplant concentrations remained low, returning to their normal levels post-transplantation. Pretransplant DLCOSB levels were slightly decreased but fell within the therapeutic range after correction for Hb concentration, unlike the mean KCO levels which remained slightly diminished despite their correction. In post-transplant controls, the values obtained for both DLCOSB and KCO were significantly higher at the different post-transplant intervals (P < 0.005) than pretransplantation but only when compared without Hb correction. No significant differences for DLCOSB were found when corrected values were compared, and an improvement in the KCO appeared to be significant at 12 months posttransplantation. Based on these findings, we feel that when serum levels are within the therapeutic range, cyclosporin fails to alter the respiratory function or the pulmonary diffusing capacity of the lung.

[Patients with chronic airflow limitation: effects of the inspiratory muscle training with threshold load valve, built with appropriate technology, associated to nutritional support]

AIM

To assess prospectively the effects of a controlled program of inspiratory muscle training program and nutritional support in patients with chronic obstructive lung disease (COPD).

PATIENTS AND METHODS

Twenty-three patients with COPD were randomly assigned into four groups. Group I received a 1000 kcal/day nutritional supplement, given as a casein based enteral nutritional formula; group III was subjected to inspiratory muscle training, using an inexpensive pressure threshold load valve constructed according to the Appropriate Technology principles of the WHO, adjusted at 30% of Maximal Inspiratory Mouth Pressure and received also the nutritional supplement; group IV was trained but did not receive the nutritional supplement and group II was not trained nor supplemented. Patients were studied during three months and monthly, inspiratory muscle function, exercise capacity and anthropometry were measured.

RESULTS

A significant improvement in exercise capacity, maximal inspiratory pressure and inspiratory muscle endurance was observed in the four groups throughout the study. Trained subjects had greater improvement in their inspiratory muscle endurance, compared to untrained subjects. Nutritional support had no effect in inspiratory muscle function or exercise capacity. No changes in anthropometric measures were observed.

CONCLUSIONS

The pressure threshold load valve used in this study, improved inspiratory muscle endurance and nutritional support had no effect in patients with COPD.

Structure-activity relationships for unsaturated dialdehydes. 10. The generation of bioactive products by autoxidation of isovelleral and merulidial

The autoxidation of the two mutagenic and antimicrobial sesquiterpenes merulidial (1a) and isovelleral (5) generates a number of bioactive products that are suggested to be partly responsible for the mutagenic and antimicrobial activities of the two compounds. The biological activities of the autoxidation products are, as far as has been possible to assay, of the same order as the parent compounds, and it is shown that they are formed in normal bioassay media. Merulidial (1a) is especially interesting, as its rate of autoxidation is considerably higher compared with non-mutagenic derivatives of 1a. In addition, natural isovelleral [(+/-)-5] was found to be twice as mutagenic as synthetic isovelleral [(+/-)-5], indicating that (-)-isovelleral is only weakly active or inactive, and supporting the suggestion that the interaction of isovelleral (5) and its derivatives with DNA depends on the absolute stereochemistry of the unsaturated dialdehyde moiety.

Sperm binding to the human zona pellucida after migration through human cervical mucus

During lactational amenorrhea a special type of cervical mucus, similar to that found during the luteal phase, is produced. This mucus, however, is able to support sperm migration. In the study described, the ability of spermatozoa to bind to the human zona pellucida (hZP) after migration through periovulatory and post-partum mucus was studied. Mucus was obtained from exclusively breastfeeding women in amenorrhea at 30, 60, 120 and 180 days post-partum. Periovulatory mucus samples from normally cycling women were used as a control. Flat capillary tubes were filled with BWW culture medium at the top and cervical mucus at the bottom. The tubes were immersed in a semen reservoir and the spermatozoa allowed to migrate through the mucus for 3 h into the culture media. Then the spermatozoa were coincubated with 3-4 hZP for 30 min and the number of bound spermatozoa per zona was counted. Periovulatory cervical mucus had an average Insler score of 14 +/- 0.5 as compared to 4.6 +/- 0.4 for post-partum mucus. Spermatozoa recovered from periovulatory mucus were always able to bind to the hZP in only 68 +/- 7% of the cases. Moreover, spermatozoa recovered from post-partum mucus bound to the ZP in lower numbers than did spermatozoa recovered fro periovulatory mucus (p < 0.03). These results suggest a greater ability of sperm-hZP binding after migration through periovulatory mucus and they also indicate that sperm binding to the ZP is possible even after sperm migration through a low quality mucus.

Pigmented basal cell carcinoma: an unusual case

The case of a 66-year-old man who presented with an extensive pigmented basal cell carcinoma of the left cheek is reported. Treatment consisted of irradiation and staged surgical resections. The cosmetic result was excellent, and the patient has been free of the cheek tumor for 2 1/2 years. The numerous problems inherent in the treatment of patients with disfiguring facial skin malignancies were surmounted by a multidisciplinary team in which radiotherapy, plastic surgery, and dental services participated.