Importancia de la apropiada selección de aditamentos protésicos sobre implantes para conservar el estado de salud gingival: reporte de caso / Importance of the appropriate selection of prosthetic attachments on implants to preserve the state of gingival health: case report

Introducción: La rehabilitación oral en pacientes edéntulos parciales que requieren implantes dentales ha incrementado su demanda en los últimos años, convirtiéndose en un tratamiento de rutina, donde procedimientos quirúrgicos y protésicos tienen un éxito considerable. En algunos casos estas complicaciones se resuelven de forma simple, en otros, se necesita de una mejor planificación. Objetivo: Modificar y complementar el plan de tratamiento del paciente como solución definitiva al posicionamiento equivocado de los implantes dentales oseo integrados. Presentación del Caso: Paciente de 64 años, hombre, asistió a Centro de Atención Odontológica de la Universidad de Las Américas (CAO/UDLA), para terminar tratamiento odontológico de especialidad, rehabilitación de cuatro implantes colocados en zona 1.6 (Mis: C1 4.20 x 13mm); 1.4 (Mis: C1 3.75x11.50 mm); 1.2 (Mis: C1 3.75 x 11.50 mm); 2.1 (Mis: C1 4.20 x 11.50 mm), a examen clínico se pudo observar prótesis acrílica transicional inmediata desadaptada e inestable oclusalmente como resultado de proceso de cicatrización de tejidos, pérdida de piezas dentales postero-inferiores (3.6; 3.7; 4.6 y 4.7).La angulación equivocada de los implantes anteriores obligó la necesidad de corregirla mediante el uso de aditamentos rotacionales Multi-unit rectos de 2 mm altura en implantes 1.6; 1.4, aditamentos anti rotacionales tipo Multi-unit angulados de 1 mm de altura a 30º para los implantes 1.2 y 2.1 con healingcaps para proteger el aditamento de la acumulación de placa bacteriana y facilitar la higienización e inserción de la prótesis múltiple. Conclusiones: Los aditamentos colocados modificaron y complementaron la rehabilitación de los implantes incluso en la zona anterior donde se encontró tejido mucoso insuficiente que cubra de forma completa el aditamento elegido. (AU)

Introduction: Oral rehabilitation in partial edentulous patients who require dental implants has increased its demand in recent years, becoming a routine treatment, where surgical and prosthetic procedures have considerable success In some cases these complications are resolved simply, in others. Aims: Better planning is needed modify and complement the patient’s treatment plan as a definitive solution to the wrong positioning of osseointegrated dental implants. Presentation of the Case: Patient of 64 years, man, attended the Dental Care Center of the University of the Americas (CAO / UDLA), to finish specialty dental treatment, rehabilitation of four implants placed in zone 1.6 (Mis: C1 4.20 x 13mm); 1.4 (Mis: C1 3.75x11.50 mm); 1.2 (Mis: C1 3.75 x 11.50 mm); 2.1 (Mis: C1 4.20 x 11.50 mm), On clinical examination, immediate transitional acrylic prosthesis could be observed maladapted and occlusally unstable as a result of tissue healing process, loss of postero-inferior teeth (3.6; 3.7; 4.6 and 4.7). The wrong angulation of the previous implants forced the need to correct it through the use of 2 mm high straight Multi-unit rotational attachments in implants 1.6; 1.4, angled Multi-unit anti-rotational attachments from 1 mm high to 30 mm for implants 1.2 and 2.1 with healing caps to protect the attachment from the accumulation of bacterial plaque and facilitate the sanitization and insertion of the multiple prosthesis. Conclusions: The attachments placed modified and complemented the rehabilitation of the implants even in the anterior area where insufficient mucous tissue was found to completely cover the chosen attachment. (AU)

GABAρ3 expression in lobule X of the cerebellum is reduced in the valproate model of autism.

Autism spectrum disorder (ASD) is a group of developmental disorders characterized by social interaction deficits, communication impairments, and stereotyped and repetitive behaviors. Additionally, impairments in the GABAergic circuitry have been associated with ASD. Several studies have shown that dysfunction of the cerebellum is a hallmark of ASD, and postmortem studies in humans reported a reduced density of Purkinje cells (PCs) together with an abnormal expression of GABAA subunits, among which GABAρ3 is expressed in early postnatal development, forms homomeric receptors with high affinity to the agonist (GABA EC50 ∼ 3 µM) and desensitize very little upon activation. Thus, we tested if the expression of GABAρ3 was modified by prenatal exposure to valproate (VPA), a well-known murine model of autism. The latency to find the nest increased in VPA-treated mice when compared to controls at postnatal day 8 (P8). Immunofluorescence studies showed a reduced expression of GABAρ3 in Purkinje cells (PCs) and ependymal glial cells (EGCs) from lobule X of VPA-treated mice. Finally, the expression of GABAρ3 increases linearly throughout normal development of the cerebellum, but this pattern is disrupted in the VPA model of autism. We conclude that the expression of GABAρ3 is reduced in PCs and EGCs from lobule X of the cerebellum in the VPA model of autism. Thus, GABAρ3 may be a relevant marker for ASD etiology.

Long-term fish oil supplementation attenuates seizure activity in the amygdala induced by 3-mercaptopropionic acid in adult male rats.

Several studies have provided evidence of significant effects of omega-3 fatty acids on brain functionality, including seizures and disorders such as epilepsy. Fish oil (FO) is a marine product rich in unsaturated omega-3 fatty acids. Considering that the amygdala is one of the brain structures most sensitive to seizure generation, we aimed to evaluate the effect of long-term chronic FO supplementation (from embryonic conception to adulthood) on the severity of seizures and amygdaloid electroencephalographic activity (EEG) in a 3-mercaptopropionic acid (3-MPA)-induced seizure model using adult rats. Female Wistar rats were fed a commercial diet supplemented daily with FO (300mg/kg) from puberty through mating, gestation, delivery, and weaning of the pups. Only the male pups were then fed daily with a commercial diet supplemented with the same treatment as the dam up to the age of 150days postpartum, when they were bilaterally implanted in the amygdala to record behavior and EEG activity before, during, and after seizures induced by administering 3-MPA. Results were compared with those obtained from rats supplemented with palm oil (PO) and rats treated with a vehicle (CTRL). The male rats treated with FO showed longer latency to seizure onset, fewer convulsive episodes, and attenuated severity compared those in the PO and CTRL groups according to the Racine scale. Moreover, long-term FO supplementation was associated with a reduction of the absolute power (AP) of the fast frequencies (12-25Hz) in the amygdala during the seizure periods. These findings support the idea that chronic supplementation with omega-3 of marine origin may have antiseizure properties as other studies have suggested.

Efectividad de terapia restrictiva combinada con terapia ocupacional y física en la función motora de extremidad superior en niños con parálisis cerebral tipo hemiparesia / Effectiveness of restrictive therapy combined with occupational and physical therapy on upper extremity motor function in children with cerebral palsy hemiparesis

Introduction: restrictive therapy is effective to enhance affected upper limb use, however combined therapy application protocols and use of instruments to evaluate results, vary. Objective: to evaluate changes in motor function of the affected upper extremity, following the application of restrictive therapy combined with occupational and physical therapy, in 7 to 13 year old children with cerebral palsy (CP) hemiparesis. Methods and patients: a cohort study of nine children, mean age 10 +/- 2.3 years, without affected upper limb function treatment in the previous ≥ 6 months. The intervention consisted of restriction of the undamaged limb for two months, 20 therapy sessions twice a week, and a home work program. Shriner’s Hospital upper extremity evaluation protocol (SHUEE) and a stereognosis test were applied prior to, and at 1 and 3 months post intervention. Results: median values for dynamic posture analysis and grasp-release, increase significantly when all three evaluations are considered, and at discharge and follow-up, as compared to baseline levels. Spontaneous functional use increases median value with respect to baseline, without statistical significance. At treatment finalization, stereognosis median reaches 100 percent, achieving an optimal performance maintained at follow-up. Conclusion: restrictive therapy combined with occupational and physical therapy is effective to achieve changes in motor function of affected upper limbs in children with CP hemiparesis, as evaluated with SHUEE.

Introducción: la terapia restrictiva es efectiva para potenciar uso de extremidad superior (EESS) comprometida, pero los protocolos de aplicación en forma combinada y uso de instrumentos para evaluar resultados, son variados. Objetivo: evaluar cambios en función motora de EESS comprometida, por aplicación de terapia restrictiva en combinación con terapia ocupacional y física, en niños de 7 a 13 años, portadores de parálisis cerebral (PC) tipo hemiparesia. Pacientes y métodos: estudio de cohorte de 9 niños, edad promedio 10 +/- 2,3 años, sin tratamiento que estimule función de EESS comprometida en un período previo ≥ 6 meses. La intervención consistió en restricción de mano indemne por 2 meses, 20 sesiones de terapia dos veces por semana, y protocolo para trabajo en el hogar. Se aplicó evaluación de EESS del Hospital de Niños de Shriners (SHUEE) y test deestereognosia, las que fueron efectuadas antes, a un mes y tres meses posteriores a la intervención. Resultados: los valores de la mediana del análisis postural dinámico y agarre-liberación, aumentan en forma significativa al considerar las tres evaluaciones en su conjunto y, al alta y seguimiento respecto de medición basal. El porcentaje de uso funcional espontáneo, aumenta el valor de la mediana respecto del valor inicial, sin significancia estadística. Al finalizar la intervención, la mediana de estereognosia es de 100 por ciento, logrando óptimo desempeño mantenido al seguimiento. Conclusión: la terapia restrictiva combinada con terapia ocupacional y física, es efectiva para lograr cambios en función motora de EESS comprometida en niños con PC tipo hemiparesia, evaluado con SHUEE.

Developing a pediatric outpatient transplantation program. The Children's Memorial Hospital experience.

We describe the development of a pediatric outpatient transplant program and our initial experience with autologous and allogeneic transplants performed partially or completely in the outpatient setting. Forty-eight autologous and seven allogeneic transplants have been performed in our institution in the outpatient setting between June 1994 and July 2000. The ablation used for the autologous outpatient transplants was VP-16 1000 mg/m2/ day as a continuous infusion for 2 days and Carboplatinum 667mg/m2/day for 2 days. The autologous inpatient transplants received Thio-tepa 300-mg/ m2per day x 3 days and cyclophosphamide 60 mg/kg/day for 4 days. For those patients who received an immune-ablative allogeneic outpatient transplant, the regimen consisted of Fludarabine 30 mg/m2/day for 6 days, followed by busulfan for children less than five years of age 1 mg/kg/dose x 8 doses and for those five years and older 0.8 mg/kg/dose x 8 doses, followed by ATG 40mg/kg/day x 4 days. Engraftment was complete in all transplants achieving an ANC >500 for the outpatient transplant in 15 days (10-35) vs. the inpatient in 15 days (14-58). This was not statistically significant. They achieved un-sustained platelets >20.0 by day 19 (14-58) for the outpatients and day 32 10-64) for the inpatient. The allogeneic immune ablative transplants were considered engrafted when their VNTRs were greater that 30% which was achieved at a median of 13 days (10-27). The economic data showed a statistically significant decrease in charges and direct costs between the outpatient (median charges $30 775, direct costs $8 389) and the inpatient (median charges $99 838, direct costs $42 757) transplants (p0.001). There was no difference in morbidity and mortality between the two groups but the use of empiric amphotericin B was markedly decreased in the outpatient transplants. In conclusion it is feasible and less costly to perform autologous hematopoietic stem cell transplants in the outpatient setting with no increase in morbidity and mortality. For the allogeneic transplants there is not yet enough data to establish a similar conclusion.

Pig liver carnitine palmitoyltransferase I, with low Km for carnitine and high sensitivity to malonyl-CoA inhibition, is a natural chimera of rat liver and muscle enzymes.

The outer mitochondrial membrane enzyme carnitine palmitoyltransferase I (CPTI) catalyzes the initial and regulatory step in the beta-oxidation of fatty acids. The genes for the two isoforms of CPTI-liver (L-CPTI) and muscle (M-CPTI) have been cloned and expressed, and the genes encode for enzymes with very different kinetic properties and sensitivity to malonyl-CoA inhibition. Pig L-CPTI encodes for a 772 amino acid protein that shares 86 and 62% identity, respectively, with rat L- and M-CPTI. When expressed in Pichia pastoris, the pig L-CPTI enzyme shows kinetic characteristics (carnitine, K(m) = 126 microM; palmitoyl-CoA, K(m) = 35 microM) similar to human or rat L-CPTI. However, the pig enzyme, unlike the rat liver enzyme, shows a much higher sensitivity to malonyl-CoA inhibition (IC(50) = 141 nM) that is characteristic of human or rat M-CPTI enzymes. Therefore, pig L-CPTI behaves like a natural chimera of the L- and M-CPTI isotypes, which makes it a useful model to study the structure--function relationships of the CPTI enzymes.

Low activity of mitochondrial HMG-CoA synthase in liver of starved piglets is due to low levels of protein despite high mRNA levels.

The unusually low hepatic ketogenic capacity of piglets has been correlated with lack of expression of the mitochondrial HMG-CoA synthase gene. However, we have shown that starvation of 2-week-old piglets increased the mRNA levels of mitochondrial HMG-CoA synthase to a level similar to that observed in starved rats (S. H. Adams, C. S. Alho, G. Asins, F. G. Hegardt, and P. F. Marrero, 1997, Biochem. J. 324, 65-73). We now report that antibodies against pig mitochondrial HMG-CoA synthase detected the pig enzyme in mitochondria of 2-week-old starved piglets and that the pig mitochondrial HMG-CoA synthase cDNA encodes an active enzyme in the eukaryotic cell line Mev-1, with catalytic behavior similar to that of the rat enzyme when expressed in the same system. We also show that low activity of pig mitochondrial HMG-CoA synthase correlates with low expression of the pig enzyme. The discrepancy in mitochondrial HMG-CoA synthase gene expression between the high levels of mRNA and low levels of enzyme was not associated with differences in transcript maturation, which suggests that an attenuated translation of the pig mRNA is responsible for the diminished ketogenic capacity of pig mitochondria.

Differential expression of cytosolic and mitochondrial 3-hydroxy-3-methylglutaryl CoA synthases during adipocyte differentiation.

Mitochondrial and cytosolic 3-hydroxy-3-methylglutaryl CoA synthase (m-HMS and c-HMS) genes show high identity at the nucleotide and amino acid level, but no homology has been found in the promoter area. The main regulator for c-HMS is SREBP. The best known transcription factor that regulates m-HMS is PPAR alpha. Three types of PPAR, alpha, gamma and delta have been described in vertebrates. Here we found that they display distinct ligand response profiles in the m-HMS promoter. In some conditions PPAR gamma is a significant activator of m-HMS. Thus, the m-HMS gene is transiently expressed during the clonal expansion phase of 3T3-L1 differentiation. We found that C/EBP delta and PPAR gamma activate the m-HMS promoter in 3T3-L1 cells synergistically. This synergistic effect was only observed in the whole promoter (-1148 to +28). A small construct (-116 to +28) which contains the PPRE did not respond to C/EBP delta and/or PPAR gamma. This suggests that a putative C/EBP site lie somewhere between -1148 and -116 bp. We also show that C/EBP delta was more efficient that C/EBP alpha and C/EBP beta to activate the m-HMS promoter. The time course of c-HMS mRNA expression during 3T3-L1 differentiation was different, with a significant increase at terminal adipogenesis. We found that the transcription factor C/EBP alpha did not activate the c-HMS promoter. The differential pattern of expression shown by these two genes, which have a common ancestor, exemplifies refinements of transcriptional control during evolution.

Blockade of currents by the antimalarial drug chloroquine in feline ventricular myocytes.

The effects of the antimalarial drug chloroquine on cardiac action potential and membrane currents were studied at clinically relevant concentrations. In cat Purkinje fibers, chloroquine at concentrations of 0.3 to 10 microM increased action potential duration, and reduced maximum upstroke velocity. At concentrations of 3 and 10 microM, chloroquine increased automaticity and reduced maximum diastolic potential, and after 60 min of perfusion with a concentration 10 microM, spontaneous activity was abolished. In isolated cat ventricular myocytes, chloroquine also increased action potential duration in a concentration-dependent manner, and reduced resting membrane potential at 3 and 10 microM. In voltage-clamped cat ventricular myocytes, chloroquine blocked several inward and outward membrane currents. The order of potency was inward rectifying potassium current (I(K1)) > rapid delayed rectifying potassium current (I(Kr)) > sodium current (I(Na)) > L-type calcium current (I(Ca-L)). Only tonic block of I(Na) and I(Ca-L) was observed at a stimulation frequency of 0.1 Hz and no additional blockade was observed during stimulation trains applied at 1 Hz. The effect of chloroquine on I(K1) was voltage-dependent, with less pronounced blockade at negative test potentials. In addition, unblock was achieved by hyperpolarizing pulses to potentials negative to the current reversal potential. Chloroquine blocked the rapid component of the delayed rectifying outward current, I(Kr,) but not the slow component, I(Ks). These findings provide the cellular mechanisms for the prolonged QT interval, impaired ventricular conduction, and increased automaticity induced by chloroquine, which have been suggested as responsible for the proarrhythmic effects of the drug.

Regulation of the rat liver carnitine palmitoyltransferase I gene transcription by thyroid hormone.

L-CPT I isotype is the main locus of control for liver LCFA oxidation. T3 levels have been described as controlling L-CPT I gene expression, and in this paper we demonstrate that rat liver CPT I promoter responds to T3. Using deleted reporter constructs we located the thyroid hormone-responsive element between -2935 and -2918, consisting of a DR4. This response is mediated by the binding of the thyroid to this sequence as a monomer, homodimer, or heterodimer with RXR.

Contribution of steroidogenic factor 1 to the regulation of cholesterol synthesis.

Steroidogenic factor 1 (SF-1) is an orphan member of the nuclear receptor family expressed in steroidogenic tissues, where it has an essential role in the regulation of the steroid hormone biosynthesis, adrenal and gonadal development and endocrine responses fundamental for reproduction. Here we show that SF-1 regulates the transcription of cytosolic 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) synthase gene, which is essential for the endogenous synthesis of cholesterol. We have identified an element located 365 bp upstream of the gene for cytosolic HMG-CoA synthase; SF-1 binds as a monomer to this element and confers SF-1 responsiveness to homologous and heterologous promoters. It has been shown that in tissues with a high demand for cholesterol to be used in steroid synthesis, there is a lack of correlation between the cholesterol levels and the activity of the limiting enzymes of the mevalonate pathway. In accord with those results, we observed that cholesterol synthesis from acetate and either cytosolic HMG-CoA mRNA expression or transcriptional activity were not changed in response to 25-hydroxycholesterol in the SF-1-expressing steroidogenic Leydig tumour MA-10 cells. Moreover, the overexpression of SF-1 in non-steroidogenic CV-1 cells renders them less sensitive to the regulatory effects of cholesterol. This observation led to the hypothesis that in steroidogenic tissues the expression of SF-1 permits high levels of endogenous synthesis of cholesterol irrespective of the intracellular levels of this metabolite.

Chloroquine blocks the background potassium current in guinea pig atrial myocytes.

In this study we examined the effects of chloroquine on the muscarinic potassium current, I(K-ACh), and the inward rectifying potassium current, I(K1). We utilized three ways to induce I(K-ACh): activating the M2-muscarinic receptors with carbachol, activating the purinergic A1-receptors with adenosine and directly activating the G(K)-protein coupled with these receptors in an irreversible way with GTPgammaS. In experiments using the whole-cell configuration of the patch-clamp technique, we found that chloroquine, independently from the manner of activation of I(K-ACh), was able to block this current with similar potency. These results strongly suggest that chloroquine may be acting directly on the muscarinic potassium channel. Chloroquine also blocked I(K1) with similar potency, in both guinea pig atrial and ventricular myocytes.

Sterol regulatory element binding protein-mediated effect of fluvastatin on cytosolic 3-hydroxy-3-methylglutaryl-coenzyme A synthase transcription.

The effects of acute treatment with fluvastatin, a hypocholesteremic drug, on the mRNA levels of several regulatory enzymes of cholesterogenesis and of the LDL receptor were determined in rat liver. Fluvastatin increased the hepatic mRNA levels for HMG-CoA reductase up to 12-fold in 5 weeks of treatment at a daily dose of 6. 3 mg/kg. The effect was less marked in cytosolic HMG-CoA synthase, farnesyl-PP synthase, squalene synthetase, and LDL receptor. SREBP-2 mRNA levels were also increased, but SREBP-1 were not. De novo synthesis of cholesterol in several cultured cells was reduced by increasing concentrations of fluvastatin, and the IC(50) values of fluvastatin in HepG2, CV-1, and CHO cells were respectively 0.01, 0. 05, and 0.1 microM. When CHO cells stably transfected with a chimeric gene composed of the promoter of cytosolic HMG-CoA synthase and the CAT gene as a reporter were incubated with fluvastatin, the CAT gene was overexpressed, an effect which was similar to the cotransfection with the processed form of SREBP-1a. Both ALLN and fluvastatin increased the transcriptional activity of cytosolic HMG-CoA synthase. Mutation in either SRE or NF-Y boxes abolished the increase in transcriptional rate caused by fluvastatin in the promoter of cytosolic HMG-CoA synthase. These results indicate that the increase in transcriptional activity in the HMG-CoA synthase gene attributable to fluvastatin is a consequence of the activation of the proteolytic cleavage of SREBPs by reduced levels of intracellular cholesterol.

Isolation of pig mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase gene promoter: characterization of a peroxisome proliferator-responsive element.

Low expression of the mitochondrial 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) synthase gene during development correlates with an unusually low hepatic ketogenic capacity and lack of hyperketonaemia in piglets. Here we report the isolation and characterization of the 5' end of the pig mitochondrial HMG-CoA synthase gene. The 581 bp region proximal to the transcription start site permits transcription of a reporter gene, confirming the function of the promoter. The pig mitochondrial HMG-CoA synthase promoter is trans-activated by the peroxisomal proliferator-activated receptor (PPAR), and a functional response element for PPAR (PPRE) has been localized in the promoter region. Pig PPRE is constituted by an imperfect direct repeat (DR-1) and a downstream sequence, both of which are needed to confer PPAR-sensitivity to a thymidine kinase promoter and to form complexes with PPAR.retinoid X receptor heterodimers. A role of PPAR trans-activation in starvation-associated induction of gene expression is suggested.

Control of human muscle-type carnitine palmitoyltransferase I gene transcription by peroxisome proliferator-activated receptor.

The expression of several genes involved in intra- and extracellular lipid metabolism, notably those involved in peroxisomal and mitochondrial beta-oxidation, is mediated by ligand-activated receptors, collectively referred to as peroxisome proliferator-activated receptors (PPARs). To gain more insight into the control of expression of carnitine palmitoyltransferase (CPT) genes, which are regulated by fatty acids, we have examined the transcriptional regulation of the human MCPT I gene. We have cloned by polymerase chain reaction the 5'-flanking region of this gene and demonstrated its transcriptional activity by transfection experiments with the CAT gene as a reporter. We have also shown that this is a target gene for the action of PPARs, and we have localized a PPAR responsive element upstream of the first exon. These results show that PPAR regulates the entry of fatty acids into the mitochondria, which is a crucial step in their metabolism, especially in tissues like heart, skeletal muscle and brown adipose tissue in which fatty acids are a major source of energy.

The hepatocyte nuclear factor 4 (HNF-4) represses the mitochondrial HMG-CoA synthase gene.

We have recently shown that the gene for the mitochondrial HMG-CoA synthase is a target for PPAR and that this receptor mediates the induction of this gene by fatty acids. With the aim of gaining further insight into the function and regulation of this gene we examined the effect of other members of the nuclear hormone receptor superfamily on its expression. We previously identified a regulatory element in the mitochondrial HMG-CoA synthase gene promoter that confers transcriptional regulation by PPAR, RXR and the orphan nuclear receptor COUP-TF. In this study we demonstrate a trans-repressing regulatory function for HNF-4 at this same nuclear receptor response element (NRRE). HNF-4 binds to the mitochondrial HMG-CoA synthase NRRE, and, in cotransfection assays in HepG2 cells, it represses PPAR-dependent activation of reporter gene linked to the mitochondrial HMG-CoA synthase gene promoter. These results suggest that the mitochondrial HMG-CoA synthase gene is subject to differential regulation by the interplay of multiple members of the nuclear hormone receptor superfamily.

Chicken ovalbumin upstream-promoter transcription factor (COUP-TF) could act as a transcriptional activator or repressor of the mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase gene.

The chicken ovalbumin upstream-promoter transcription factor (COUP-TF) has a dual effect on the regulation of the mitochondrial 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) synthase gene. COUP-TF could act as a transcriptional activator or repressor of this gene through different DNA sequences. COUP-TF induces expression of a reporter gene linked to the mitochondrial HMG-CoA synthase gene promoter in human hepatoma HepG2 cells, but represses it in a Leydig tumour cell line (R2C); in both these cell lines the expression of the mitochondrial HMG-CoA synthase gene mimics that of liver and testis. The activation is promoted by a fragment of the gene from coordinates -62 to +28, which contains a GC box and a TATA box, and where no COUP-TF binding site was observed by in vitro DNA binding studies. On the other hand, the COUP-TF inhibitory effect is mainly due to repression of peroxisome-proliferator-activated receptor-dependent activation of the gene, interacting with the region from -104 to -92. To our knowledge this work represents the second example of a target gene for COUP-TF I that could be either activated or repressed by the action of this receptor through different DNA sequences of the same gene.

Continuous oesophageal aortic blood flow echo-Doppler measurement during general anaesthesia in infants.

PURPOSE: Invasive haemodynamic monitoring during general anaesthesia in infants is usually limited to very high risk operations, such as cardiac surgery. Nevertheless, different surgical procedures and/or anaesthetic techniques justify additional monitoring for children, as for adults. The aim of this preliminary study was to evaluate the feasibility of using a new echo-Doppler device (Dynemo 3000) capable of measuring continuous aortic blood flow during general anaesthesia in infants. METHODS: Aortic blood flow (ABF) was measured with a small oesophageal probe designed for newborns and infants. The aortic flowmeter was connected with satellite devices to visualise the haemodynamic profile which included ABF, pre-ejection period (PEPi), left ventricular ejection time (LVETi), mean arterial pressure, heart rate, stroke volume and systemic vascular resistance. Twelve infants, aged 8-26 mo, undergoing surgery under general anaesthesia were successively included in the evaluation of this device. Isoflurane (1% end-expired concentration) was introduced to maintain anaesthesia after induction with halothane, midazolam, fentanyl and atracurium. RESULTS: Correct positioning of the probe was easily obtained in all cases and the recording quality was excellent, whatever the operative position. Recordings of haemodynamic data showed some myocardial depression from isoflurane: decreased ABF (indexed to body surface area) and lengthened PEP/LVET (2.24 +/- 0.53 L.min-1.m-2 and 0.32 +/- 0.05 respectively, before introduction of isoflurane and 1.71 +/ 0.53 L.min-1.m-2 (P = 0.027) and 0.39 +/- 0.06 (P = 0.007) with isoflurane). CONCLUSION: These preliminary results suggest that this continuous ABF echo-Doppler device may be valuable for peri anaesthetic monitoring in infants.

A nonsense mutation in the 3-hydroxy-3-methylglutaryl-CoA lyase gene produces exon skipping in two patients of different origin with 3-hydroxy-3-methylglutaryl-CoA lyase deficiency.

A novel nonsense mutation associated with the skipping of constitutive exon 2 of the 3-hydroxy-3-methylglutaryl-CoA lyase gene was found in two patients, from Portugal and Morocco, with 3-hydroxy-3-methylglutaric acidemia. By reverse transcriptase PCR and single-strand conformational polymorphism a G-T transversion was located, at nucleotide 109, of the 3-hydroxy-3-methylglutaryl-CoA lyase cDNA, within exon 2. Two mRNAs were produced as a result of this nonsense mutation: one of the expected size that contains the premature stop codon UAA, and the other with a deletion of 84 bp corresponding to the whole of exon 2. This deletion produced the loss of the last seven amino acids of the leader peptide and the first 21 amino acids of the mature protein. The nonsense mutation was found in a purine-rich GGAAG sequence, which is equal to, or similar to, others reported to be exonic splicing enhancers (ESE). We suggest that the nonsense mutation may affect a possible ESE on exon 2, which would hinder the splice site selection and facilitate an aberrant splice with the skipping of this exon. Determination by quantitative PCR shows that the ratio of mRNA with the nonsense mutation to the mRNA with the deletion is approx. 3:1.