Massive intravascular haemolysis in a patient with Clostridium perfringens sepsis.
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Aged↗
Biomedical subjects
M Jimenez
Publications and source records attributed to M Jimenez.
[Value of fetal echocardiography in screening for congenital heart diseases. Report of 1,049 consecutive examinations].
Specialised antenatal echocardiographic screening has allowed 1049 consecutive examinations in 992 patients resident in the Aquitaine region over a period of nine years. The most frequently encountered indications are expertise (suspicion of cardiopathy during initial screening) and family history. Expertise allows a higher detection rate (46.5%) compared to the other indications. We have screened 150 cardiopathies in utero and among them 143 were able to followed up after delivery. We have noticed a much greater severity of the anomalies compared to those encountered in paediatric cardiology. An associated chromosomal anomaly was noticed in 9% of cases and more frequently for atrio-ventricular communication and conotruncal cardiopathies. The rate of abortion was 35%, and the mortality for the surviving pregnancies was elevated (35%). Pharmacological treatment was instituted in 95% of cases of sustained supraventricular tachycardia with 81% successful. Diagnosis errors concerned benign cardiopathies above all and did not change the management of the pregnancy. The sensitivity of fetal echocardiography was 93.1% and its specificity 99.1%. This study shows the viability of fetal cardiac echography for the detection of the majority of congenital cardiopathies in a population at risk and in the management of fetal cardiac rhythm disorders. Nevertheless it remains a specialised examination for which the performance depends much on the initial screening performed by gynaecologists. Although the mortality rate of the screened children is elevated, indicating the frequent parental choice of abortion and the complexities of the cardiopathies, antenatal diagnosis has allowed optimisation of the neonatal management for certain curable cardiopathies.
Abortion, Induced↗
[Placement of an implantable defibrillator via the endocavitary route in a patient presenting with a univentricular heart and a Glenn anastomosis].
We report the observation of a female 45 year old patient presenting with a post-surgery complex congenital cardiopathy, associated with serious ventricular rhythm disorders necessitating the placement of an implantable defibrillator. The palliative surgery performed (cavo-pulmonary Glenn anastomosis) does not allow the usual access to the right ventricle via the superior vena cava. The different possibilities for defibrillator implantation are discussed. These include associating a surgical approach to introduce the bipolar probe with subcutaneous tunnelling to connect the probe to the box.
Arrhythmias, Cardiac↗
[Ebstein anomaly. Developmental aspects].
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Adolescent↗
[Ebstein's anomaly].
Since Ebstein's first description in 1866 and the first surgical attempts at treatment in the 1950's, the natural history of this condition remains obscure. The anatomical description contrasts with the clinical and prognostic variability of this malformation. The form observed in the foetal or prenatal periods has a very different prognosis to that observed in adults. The risk factors are not the same even though the anatomical entity is comparable. The difficulty in managing these patients is due to the problems of diagnosis and determination of these prognostic factors. Advances in echocardiography, the key investigation which facilitates diagnosis, and in surgical and ablation techniques, have improved our understanding of this condition and its prognosis.
Adult↗
[Outcome of operated Fallot's tetralogy].
Fifty years after the beginning of cardiac surgery, a large percentage of operated congenital heart disease patients attain adulthood. The tetralogy of Fallot is one of the malformations in which the natural outcome was unfortunately nearly fatal in the long-term. Open heart surgery has radically transformed the prognosis of this, the most common of all cyanotic congenital cardiac malformations. Nowadays, most operated patients lead normal professional and family lives. Lonf-term survival after correction is between 90-95% after 30-35 years. Although surgical repair is satisfactory, the operated heart is not anatomically normal. The patients have a variable degree of devalvulation of the pulmonary outflow tract, a scar on the right ventricle, a patch repairing the ventricular septal defect and scars on the atrium (cannulation for cardiopulmonary bypass). These sequellae expose the patients to a number of complications, notably arrhythmic and sometimes haemodynamic, affecting the right ventricle. The late mortality rate varies from 5 to 13% in the literature. The main causes of death are sudden death and reoperation. Sudden death is the most severe long-term complication but it is uncommon, affecting less than 5% of the population. It is mainly due to ventricular arrhythmias. Certain predisposing factors should be identified during long-term follow-up, among them the presence of haemodynamic abnormalities: systolic overload (residual pulmonary stenosis) or diastolic overload of the right ventricle (pulmonary regurgitation), infundibular aneurysm, right ventricular dysfunction. It would appear to be important to prevent pulmonary regurgitation by preserving the pulmonary valve even if it means persistence of a mild transvalvular pressure gradient. When pulmonary regurgitation is inevitable, follow-up is essential to evaluate the timing of valvulation of the pulmonary orifice. Despite these different complications which must be understood for proper follow-up of these patients, the long-term outcome of operated tetralogy of Fallot remains very good.
Adult↗
Cold-induced changes in the energy coupling and the UCP3 level in rodent skeletal muscles.
The mechanism of thermoregulatory uncoupling of respiration and phosphorylation in skeletal muscles has been studied. It is found that 24 h cold exposure results in (i) a 3-fold increase in the amount of UCP3 protein in rat skeletal muscle mitochondria, and (ii) pronounced lowering of the membrane potential in isolated rat or mouse skeletal muscle mitochondria. The decrease in membrane potential is reversed by adding bovine serum albumin. Cold exposure is also found to sensitize the membrane potential to the uncoupling action of added fatty acid (laurate). After laurate addition, the recoupling effects of GDP and carboxyatractylate decrease whereas that of albumin increases in mitochondria from cold-treated rats or mice. Changes similar to those induced by cold can be initiated by the in vivo addition of thyroxine. Cold exposure does not affect energy coupling in liver mitochondria. The possible involvement of UCP3 isoforms in nucleotide-sensitive and -insensitive uncoupling is discussed.
Animals↗
Characterization of the alanine racemases from two mycobacteria.
D-Alanine is a necessary precursor in the biosynthesis of the bacterial peptidoglycan. The naturally occurring L-alanine isomer is racemized to its D-form through the action of a class of enzymes called alanine racemases. These enzymes are ubiquitous among prokaryotes, and with very few exceptions are absent in eukaryotes, making them a logical target for the development of novel antibiotics. The alanine racemase gene from both Mycobacterium tuberculosis and M. avium was amplified by PCR and cloned in Escherichia coli. Overexpression of the proteins in the E. coli BL21 system, both as native and as His-tagged recombinant products, has been achieved. The proteins have been purified to electrophoretic homogeneity and analyzed biochemically. A D-alanine requiring double knock-out mutant of E. coli (alr, dadX) was constructed and the cloned genes were able to complement its deficiencies.
Alanine Racemase↗
Long sleep and short sleep mice differ in nicotine-stimulated 86Rb+ efflux and alpha4 nicotinic receptor subunit cDNA sequence.
In a recent study, we reported that a restriction fragment length polymorphism associated with the alpha4 nicotinic receptor gene (Chrna4) may play a role in regulating differential sensitivity of LS and SS mouse lines to the seizure-inducing effects of nicotine. Since the alpha4 subunit (CHRNA4) is often found as a heteromer with the beta2 subunit (CHRNB2), alpha4 and beta2 cDNAs from the LS and SS mice were cloned and sequenced. A polymorphism in the coding portion of the alpha4 gene was found (1587A to G) which should result in a threonine/alanine substitution at position 529 (T529A). The LS and SS beta2 nicotinic receptor subunit cDNAs were identical. The potential consequences of the alpha4 polymorphism were evaluated using an ion (86Rb+) flux assay that likely measures the function of alpha4beta2-type receptors. LS-SS differences in maximal nicotine-stimulated ion flux were seen when bovine serum albumin (BSA) was not included but this difference was not seen when BSA was included in the perfusion buffer. Current evidence suggests that BSA may alter the ratio of nicotinic receptors that are in the ground state and desensitized forms. Thus, it may be that the Chrna4 T529A substitution leads to a difference in the ratio of the two receptor forms which then promotes differences in receptor function, as well as differential behavioural sensitivity to nicotine.
Amino Acid Sequence↗
A novel transgenic model to characterize the specific effects of follicle-stimulating hormone on gonadal physiology in the absence of luteinizing hormone actions.
Gonadal function is wholly reliant on the two pituitary-derived gonadotropins, FSH and LH. Identifying the specific effects of FSH has been difficult because of the intimate relationship between LH and FSH action and inherent limitations of classic research paradigms. We describe a novel transgenic model to characterize the definitive actions of FSH alone, distinct from LH effects, created by combining transgenic FSH expression with the gonadotropin-deficient background of the hypogonadal (hpg) mouse. A tandem transgene construct encoding each alpha- and beta-subunit of human FSH, under the rat insulin II promoter, expressed biologically active heterodimers at serum levels, by immunoassay, equivalent to circulating FSH concentrations in fertile humans (0.1-25 IU/liter). Transgenic mice were crossed into the hpg mouse genotype to obtain LH-deficient animals secreting FSH alone. Testis weights of adult FSHxhpg mice were increased up to 5-fold, relative to nontransgenic hpg controls (P < 0.001). However, only transgenic males with serum FSH levels more than 1 IU/liter showed testis weights increased relative to hpg controls, indicating a physiological FSH threshold for the testicular response. Histology of enlarged FSHxhpg testes revealed round spermatids and sparse numbers of elongated spermatids, demonstrating that the testosterone-independent FSH response targeting the Sertoli cell can facilitate completion of meiosis and minimal initiation, but not completion, of spermiogenesis. Transgenic FSH also induced inhibin B secretion in FSHxhpg mice, but showed a distinct sexual dimorphism with only females exhibiting a strong FSH dose-dependent increase in serum inhibin B levels (r(2) = 0.84). In addition, ovaries of FSHxhpg females were enlarged up to 10-fold (P < 0.001), characterized by increased follicular recruitment and development to type 7 antral follicles. Thus, these findings show that the transgenic FSHxhpg mouse provides a unique model for detailed investigations of the definitive in vivo actions of FSH alone.
Animals↗
A double-blind, placebo-controlled, randomized clinical trial of transdermal dihydrotestosterone gel on muscular strength, mobility, and quality of life in older men with partial androgen deficiency.
The efficacy and safety of androgen supplementation in older men remains controversial. Despite biochemical evidence of partial androgen deficiency in older men, controlled studies using T demonstrate equivocal benefits. Furthermore, the importance of aromatization and 5alpha reduction in androgen actions among older men remains unclear. Dihydrotestosterone is the highest potency natural androgen with the additional features that it is neither aromatizable nor susceptible to potency amplification by 5alpha reduction. Therefore, the effects of dihydrotestosterone may differ from those of T in older men. This study evaluated the efficacy and safety of 3 months treatment with transdermal dihydrotestosterone gel on muscle strength, mobility, and quality of life in ambulant, community-dwelling men aged 60 yr or older. Eligible men (plasma T < or =15 nmol/liter) were randomized to undergo daily dermal application of 70 mg dihydrotestosterone gel (n = 18) or vehicle (n = 19) and were studied before, monthly during, and 1 month after treatment. Among 33 (17 dihydrotestosterone, 16 placebo) men completing the study with a high degree of compliance, dihydrotestosterone had significant effects on circulating hormones (increased dihydrotestosterone; decreased total and free testosterone, LH, and FSH; unchanged SHBG and estradiol), lipid profiles (decreased total and low-density lipoprotein cholesterols; unchanged high-density lipoprotein cholesterol and triglycerides), hematopoiesis (increased hemoglobin, hematocrit, and red cell counts), and body composition (decreased skinfold thickness and fat mass; unchanged lean mass and waist to hip ratio). Muscle strength measured by isokinetic peak torque was increased in flexion of the dominant knee but not in knee extension or shoulder contraction, nor was there any significant change in gait, balance, or mobility tests, in cognitive function, or in quality of life scales. Dihydrotestosterone treatment had no adverse effects on prostate (unchanged prostate volumes and prostate-specific antigen) and cardiovascular (no adverse change in vascular reactivity or lipids) safety markers. We conclude that 3 months treatment with transdermal dihydrotestosterone gel demonstrates expected androgenic effects, short-term safety, and limited improvement in lower limb muscle strength but no change in physical functioning or cognitive function.
Administration, Cutaneous↗
[Myocardial infarction in a child with an anomalous left coronary artery arising from the right coronary sinus. Value of echocardiography].
An anomalous left coronary artery arising from the right sinus of Valsalva with a trajectory between the aorta and the main pulmonary artery is a rare isolated congenital anomaly carrying a high risk of sudden death and of acute myocardial ischaemia, especially in children and young adults in a context of exercise. It is usually a post-mortem finding. The authors report the rare case of a 12 year old child who suffered acute myocardial infarction on exercise due to this condition. The diagnosis was made in the acute phase by echocardiography. Surgical correction was performed as this is the only means of prevention of sudden death of an ischaemic recurrence. Effort syndromes in children or young adults should lead to a request for echocardiographic examination to exclude the diagnosis in a non-invasive manner as well as those of hypertrophic cardiomyopathy or congenital aortic stenosis.
Child↗
Involvement of asparagine 118 in the nucleotide specificity of the catalytic subunit of protein kinase CK2.
Protein kinase CK2 is a heteromeric enzyme with catalytic (alpha) and regulatory (beta) subunits which form an alpha2beta2 holoenzyme and utilizes both ATP and GTP as nucleotide substrate. Site-directed mutagenesis of CK2alpha subunit was used to study this capacity to use GTP. Deletion of asparagine 118 (alpha(deltaN118)) or the mutant alphaN118E gives a 5-6-fold increase in apparent Km for GTP with little effect on the affinity for ATP. Mutants alphaN118A and alphaD120N did not alter significantly the Km for either nucleotide. CK2alphaN118 has an apparent Ki for inosine 5' triphosphate 5-fold higher than wild-type and is very heat labile. These studies complement recent crystallographic data indicating a role for CK2alpha asparagine 118 in binding the guanine base.
Asparagine↗
Genetic and pharmacological strategies identify a behavioral function of neuronal nicotinic receptors.
The studies outlined here used pharmacological and genetic approaches to attempt to identify the nicotinic receptors that modulate nicotine-induced seizures. Full-blown clonic-tonic seizures were induced by intracerebroventricular (i.c.v.) injection of nicotine, the alpha4beta2 selective agonist ABT-418 and the alpha7-selective GTS-21. Cytisine, which is a partial agonist at alpha4beta2-type receptors, produced partial seizures. DHbetaE and MLA did not block nicotine-induced seizures. Instead, both antagonists caused seizures. Restriction fragment length polymorphisms (RFLPs) for the alpha7 receptor were identified in two inbred strains (C3H and DBA) that differ in sensitivity to nicotine-induced seizures. F2 mice derived from a C3H x DBA cross that were homozygous for the C3H variant of the alpha7 RFLP were more sensitive to nicotine-induced seizures than were F2 mice that were homozygous for the DBA RFLP. In a study that used RI strains derived from two selectively bred mouse lines (LS and SS), an association between sensitivity to nicotine-induced seizures and an RFLP associated with the alpha4 gene was found. These data support the assertion that both alpha4 and alpha7 receptor types are involved in modulating convulsions produced by nicotine.
Alkaloids↗
The short- and mid-term results of bidirectional cavopulmonary shunt with additional source of pulmonary blood flow as definitive palliation for the functional single ventricular heart.
OBJECTIVE: The purpose of this study was to demonstrate the early and late outcomes of bidirectional cavopulmonary shunt (BCPS) as a definitive procedure for the functional single ventricular heart. METHOD: From September 1991 to December 1997, 34 patients underwent a BCPS procedure without a routine conversion to Fontan circulation. The additional source of pulmonary blood flow was left in all patients. Conversion was performed only when it was required for excessive cyanosis. RESULTS: The hospital mortality rate was 8.8% (3/34, 95% confidence limit; 1.9-23%) and the 5-year survival rate was 75% for a mean follow-up period of 33+/-22 months. Seven patients underwent a conversion procedure for remnant or recurrent cyanosis and deterioration of exercise tolerance. Four of these patients died after conversion to Fontan circulation. Twenty-five long-term survivors with BCPSs maintained an arterial oxygen saturation of 84+/-6.1%, and 52% of them had a normal exercise tolerance or mild limitation. No patients developed severe late complications other than recurrent cyanosis. CONCLUSION: Due to the high mortality after conversion to Fontan circulation in patients whose conditions had deteriorated, we could not demonstrate the clear superiority of long-term BCPS over the construction of Fontan circulation for management of the functional single ventricular heart. If deteriorated conditions were successfully managed in the late period, the outcome of long-term BCPS would have been better.
Adolescent↗
Contribution of beta-adrenoceptor subtypes to relaxation of colon and oesophagus and pacemaker activity of ureter in wildtype and beta(3)-adrenoceptor knockout mice.
The smooth muscle relaxant responses to the mixed beta(3)-, putative beta(4)-adrenoceptor agonist, (-)-CGP 12177 in rat colon are partially resistant to blockade by the beta(3)-adrenoceptor antagonist SR59230A suggesting involvement of beta(3)- and putative beta(4)-adrenoceptors. We now investigated the function of the putative beta(4)-adrenoceptor and other beta-adrenoceptor subtypes in the colon, oesophagus and ureter of wildtype (WT) and beta(3)-adrenoceptor knockout (beta(3)KO) mice. (-)-Noradrenaline and (-)-adrenaline relaxed KCl (30 mM)-precontracted colon mostly through beta(1)-and beta(3)-adrenoceptors to a similar extent and to a minor extent through beta(2)-adrenoceptors. In colon from beta(3)KO mice, (-)-noradrenaline was as potent as in WT mice but the effects were mediated entirely through beta(1)-adrenoceptors. (-)-CGP 12177 relaxed colon from beta(3)KO mice with 2 fold greater potency than in WT mice. The maintenance of potency for (-)-noradrenaline and increase for (-)-CGP 12177 indicate compensatory increases in beta(1)- and putative beta(4)-adrenoceptor function in beta(3)KO mice. In oesophagi precontracted with 1 microM carbachol, (-)-noradrenaline caused relaxation mainly through beta(1)-and beta(3)-adrenoceptors. (-)-CGP 12177 (2 microM) relaxed oesophagi from WT by 61.4+/-5.1% and beta(3)KO by 67.3+/-10.1% of the (-)-isoprenaline-evoked relaxation, consistent with mediation through putative beta(4)-adrenoceptors. In ureter, (-)-CGP 12177 (2 microM) reduced pacemaker activity by 31.1+/-2.3% in WT and 31.3+/-7. 5% in beta(3)KO, consistent with mediation through putative beta(4)-adrenoceptors. Relaxation of mouse colon and oesophagus by catecholamines are mediated through beta(1)- and beta(3)-adrenoceptors in WT. The putative beta(4)-adrenoceptor, which presumably is an atypical state of the beta(1)-adrenoceptor, mediates the effects of (-)-CGP 12177 in colon, oesophagus and ureter.
Adrenergic beta-1 Receptor Antagonists↗
Identification of a novel nicotinic binding site in mouse brain using [(125)I]-epibatidine.
[(125)I]-Epibatidine binds to multiple nicotinic acetylcholine receptor (nAChR) subtypes with high affinity. In this study, [(125)I]-epibatidine was used to label and characterize a novel nAChR subtype found in mouse brain inferior colliculus, interpeduncular nucleus, and olfactory bulb homogenates. Binding of [(125)I]-epibatidine was saturable and apparently monophasic in each brain region (K:(D:)=71+/-12 pM mean+/-s.e.mean across regions) but inhibition of [(125)I]-epibatidine binding (200 pM) by A85380, cytisine and (-)-nicotine was biphasic, indicating the presence of multiple binding sites. The sites with lower agonist affinity comprised 30.0+/-2.2, 58.6+/-0.1 and 48.7+/-3.3% of specific [(125)I]-epibatidine (200 pM) binding in inferior colliculus, interpeduncular nucleus, and olfactory bulb homogenates, respectively. The affinity difference between A85380-sensitive and -resistant binding sites was particularly marked (approximately 1000 fold). Thus A85380 was used to differentiate agonist-sensitive and -resistant sites. The pharmacological profiles of the A85380-resistant sites in each region were assessed with inhibition binding experiments, using 14 agonists and five antagonists. The profiles were indistinguishable across regions, implying that A85380-resistant [(125)I]-epibatidine binding sites in inferior colliculus, interpeduncular nucleus, and olfactory bulb represent a single nAChR subtype. The pharmacological profile of the A85380-resistant sites is very different from that previously reported for high affinity (-)-[(3)H]-nicotine-, [(125)I]-alpha-bungarotoxin-, or [(125)I]-alpha-conotoxin MII-binding sites, suggesting that they represent a novel nAChR population in mouse brain.
Alkaloids↗
Femoral head disintegration in a paraplegic patient: loose bodies in neuropathic joints.
A case report of potential loose body formation in a hip joint of a paraplegic patient is presented. The case is used to discuss why loose bodies do not persist in neuropathic joints, although they might be expected to be common when this type of joint pathology exists.
Adult↗