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Biomedical subjects

J Chelly

Publications and source records attributed to J Chelly.

139 records · Page 8Linked to original sources
PubMed1979

[Prinzmetal's angina during myocardial revascularisation. Cardiovascular complications in 71 patients (author's transl)].

71 patients undergo myocardial revascularisation for Prinzmetal's angina; among them, 50 p. cent are operated upon in emergency according to three ways of anaesthesia: neuroleptanalgesia, analgesic anaesthesia, combined anaesthesia. The authors lay stress on the importance of per- and post-operative complications: electrocardiographic ischemia in 22 p. cent of the cases, severe ventricular excitability perturbations were observed in 21 p. cent, myocardial necrosis in 14 p. cent, cardiovascular collapse in 21 p. cent and hypertensions in 22 p cent. These complications are often associated. In the discussion, the authors underline anesthetic induction as a cause of Prinzmetal's angina in 50 p. cent of the cases. They put the accent on the severity of peroperative crisis followed in 50 p. cent of the cases by serious ventricular excitability perturbations. In 25 p. cent of the cases myocardial necrosis is a complication of the spasm of a coronary artery. In this field, posterior necrosis are more frequent and correspond to the spasm of the right coronary artery. All the patients of this series, except one, develop necrosis in the spastic area (by-passed or not). Per-operative hypertension has no incidence on the occurrence of post-operative complications. Lastly, continuous per-operative infusions of nitroglycerine has been performed in several patients in order to reduce morbidity of this type of surgery.

Anesthesia↗
PubMed1979

[Anesthesia for aorto-coronary bypass].

The authors have analysed a series of 357 patients undergoing aortocoronary bypass. The onset of complications was studied in relation to the past history, the anaesthetic protocol, the period of extra-corporeal circulation and the type of myocardial protection. Complications consisted of acute hypertensive episodes, arrhythmias, peroperative myocardial ischemia and myocardial infarction. The degree of beta-blocker therapy and above all its continuation up to the time of operation would seem to be an important factor in effective myocardial protection.

Anesthesia↗
PubMed1979

[Nitroglycerin and amyl nitrite action on common bile duct during operation for vesicular lithiasis (author's transl)].

Eight patients undergoing cholecystectomy received a single injection of nitroglycerin (0,9 mg) and 8 received amyl nitrite, during a cholangio-kinesimetry. The maximum fall in common bile duct pressure was similar in both group; 3.2 +/- 0.3 torr after nitroglycerin (NTG),3.8 +/- 0.6 torr after amyl nitrite (AN). NTG caused a more persistent lowering of pressure than AN; 614 +/- 42 seconds/343 +/- 27 seconds (p < 0.001). This study showed that it is possible to produce a relaxation of biliary tract muscle fibres with an injection of nitroglycerin and then replace amyl nitrite during anesthesia.

Adult↗
PubMedDate not supplied

Spectrum and distribution of MECP2 mutations in 424 Rett syndrome patients: a molecular update.

Mutations in the MECP2 (Methyl-CpG-binding protein) gene have been reported to cause Rett syndrome (RTT), an X-linked progressive encephalopathy. Recent studies have identified large gene rearrangements that escape the common PCR-based mutation screening strategy and mutations in a novel MeCP2 isoform (named MECP2B). We have collected the results of MECP2 mutational analysis concerning 424 RTT patients conducted in eight laboratories in France. In total, 121 different MECP2 mutations were identified. R168X (11.5%) is the most common of MECP2 mutations, followed by R270X (9%), R255X (8.7%), T158 M (8.3%) and R306C (6.8%). Only eight mutations had relative frequency>3%. Large and complex rearrangements not previously detected using only a PCR-based strategy represent 5.8% of MECP2 mutations. On the contrary, mutation in exon 1 appears to be rare (less than 0.5%). These data demonstrate the high allelic heterogeneity of RTT in France and suggest that routine mutation screening in MECP2 should include quantitative analysis of the MECP2 gene. This study represents an important instrument for molecular diagnosis strategy and genetic counseling in RTT families.

Cohort Studies↗
PubMedDate not supplied

Determination of the gene structure of human oligophrenin-1 and identification of three novel polymorphisms by screening of DNA from 164 patients with non-specific X-linked mental retardation.

We have recently shown that mutations in oligophrenin-1 (OPHN1) are responsible for non-specific X-linked mental retardation (MRX). The structure of the gene encoding the OPHN1 protein was determined by isolation of genomic DNA clones from the human cosmid library. Genomic fragments containing exons were sequenced, and the sequences of the exons and flanking introns were defined. Knowledge of the genomic structure of the OPHN1 gene, which spans at least 500 kb and consists of 25 exons, will facilitate the search for additional mutations in OPHN1. OPHN1 was screened for mutations in 164 subjects with non-specific mental retardation. Three nucleotide substitutions were identified, one of which was a silent mutation in the codon threonine 301 at position 903 (G-->C). The other substitutions were located in exon 2, a G-->A substitution at position 133 (A45T), and in exon 10, a C-->T substitution at position 902 (T301M), but these are common polymorphisms rather than disease-causing mutations.

Amino Acid Substitution↗
PubMedDate not supplied

Analysis of deletions in DNA from patients with Becker and Duchenne muscular dystrophy.

Duchenne muscular dystrophy (DMD) is an X-linked recessive genetic disorder for which the biochemical defect is as yet unknown. Recently, two cloned segments of human X-chromosome DNA have been described which detect structural alterations within or near the genetic locus responsible for the disorder. Both of these cloned segments were described as tightly linked to the locus and were capable of detecting deletions in the DNA of boys affected with DMD. In an attempt to determine more precisely the occurrence of these deletions within a large population of DMD patients and the accuracy of one of the segments, DXS164 (pERT87), in determining the inheritance of the DMD X chromosome, the subclones 1, 8 and 15 were made available to many investigators throughout the world. Here we describe the combined results of more than 20 research laboratories with respect to the occurrence of deletions at the DXS164 locus in DNA samples isolated from patients with DMD and Becker muscular dystrophy (BMD). The results indicate that the DXS164 locus apparently recombines with DMD 5% of the time, but is probably located between independent sites of mutation which yield DMD. The breakpoints of some deletions are delineated within the DXS164 locus, and it is evident that the deletions at the DMD locus are frequent and extremely large.

Chromosome Deletion↗
PubMedDate not supplied

Interactions between clonidine and alpha-adrenoceptor blocking drugs on the tachycardic response to stimulation of the cardiac nerve in dogs.

In pentobarbital-treated dogs clonidine (10 micrograms/kg) reduced the increase in heart rate caused by electrical stimulation of the cardiac nerve (1-10 Hz). We studied the actions of six alpha-adrenoceptor blocking drugs. Yohimbine (0.3 mg/kg) and phentolamine (1 mg/kg) potentiated the effects of nerve stimulation and antagonized the inhibitory effects of clonidine. Piperoxan (1 mg/kg) increased the response to nerve stimulation but antagonized the effects of clonidine only at the lowest frequency of stimulation. Thymoxamine (1 mg/kg) and prazosin at high doses (1 mg/kg) also antagonized the effects of clonidine but failed to increase the positive chronotropic response to stimulation of the cardiac nerve. AR-C239, a new and potent alpha-adrenoceptor blocking agent, changed neither the response to nerve stimulation nor the inhibitory effect of clonidine. The effects of all these drugs were observed at doses which reduced or reversed the pressor response to adrenaline. Therefore, our results afford further evidence for a dissimilarity between postsynaptic and presynaptic alpha-adrenoceptors in the dog. In addition, they show that the failure of an alpha-adrenoceptor blocking compound to increase the response to nerve stimulation does not necessarily indicate a lack of presynaptic alpha-adrenoceptor blockade.

Adrenergic alpha-Antagonists↗
PubMedDate not supplied

Effects of nicergoline on the cardiovascular system of dogs and rats.

In pentobarbitalized closed-chest dogs, nicergoline (10--100 microgram/kg, i.v.) reduced blood pressure, heart rate, and splanchnic nerve activity. Intracisternal administration of nicergoline (3 microgram/kg) only reduced splanchnic nerve activity. In open-chest dogs, nicergoline reduced blood pressure, cardiac output, and total peripheral resistance but did not change heart rate. In pithed rats treated with a beta-adrenoceptor-blocking agent, nicergoline reduced the pressor responses to noradrenaline and adrenaline. Nicergoline slightly attenuated the pressor responses of dogs to noradrenaline and tyramine and, in addition, reversed the hypertension induced by adrenaline and dimethylphenylpiperazinium. Nicergoline (100 microgram/kg) increased the tachycardia induced in dogs by stimulation of the right cardiovascular nerve and prevented the inhibitory effect of clonidine on this response. However, nicergoline only partially antagonized the effect of clonidine once it was fully established. Nicergoline did not antagonize the hypotensive and bradycardic effects of clonidine when they were established. Nicergoline did not affect the vagally mediated bradycardia evoked by carotid nerve stimulation in beta-adrenoceptor-blocked dogs. The compound did not change blood pressure in Cl spinal cord transected dogs. In conclusion, nicergoline appears to decrease blood pressure by blocking alpha-adrenoceptors and, at least at some doses, by a central inhibition of the sympathetic tone. Nicergoline appears to be a preferential alpha 1-adrenoceptor-blocking agent.

Animals↗
PubMedDate not supplied

[Clinical use of nitroglycerin as an hypotensive agent during general anesthesia (author's transl)].

Nitroglycerine has a direct vasodilating action on both venous and arterial smooth muscle fibers. On account of this, it has been used as hypotensive agent, in aqueous solution, on 22 surgical patients, 10 of them in neurosurgery. The total doses used were 0.76 +/- 0.12 mg/kg during 94 +/- 30 minutes (rate = 8.1 microgram/kg/min). Nitroglycerine induces a rapid onset of hypotension (3 to 4 min), spontaneously reversible in 27 +/- 8 minutes after the arrest of the infusion. The mean drop in mean arterial blood pressure achieved has been 34 p. cent. It is accompanied by a 67 +/- 9 p. cent fall of filling pressures and a fall 13 +/- 4 p. cent of cardiac index, without modification of the heart rate. Tachyphylaxis was noted 15 +/- 6 minutes following nitroglycerine infusion at rate lower than 2 microgram/kg/min, but not when the rate was above 10 microgram/kg/min. Therefore, if the drug is used to achieve controlled hypotension, high doses are necessary. No signs of toxicity were noted. In 4 cases, other hypotensive agents had been used to bring the mean arterial blood pressure below 50 Torr, which could not be achieved with nitroglycerine alone.

Adolescent↗
PubMedDate not supplied

[Pharmacology of nitroglycerin (author's transl)].

Nitroglycerin is a vasodilating agent by virtue of its actions on vascular smooth muscle fibers. It may be administered intravenously (using either 5 p. cent dextrose, or propylene-glycol solvant), sublingually, orally or by topical administration. It is rapidly metabolized, principally by liver. Its is not toxic. The vasodilatation that is produced is both arterial and venous and is dose-related in dog (1 microgram to 100 micrograms/kg/min). However, resistance and tachphylaxis may occur. Its principal use is for angor treatment, but it has been used for the treatment of arteriopathy of the lower limbs, biliar hypertony and arterial hypertension. It has been recently administered for the treatment of acute phase of myocardial infarction and during pre, per- and post-operative periods in cardiac surgery, neurosurgery and hip surgery, as myocardial protector or anti-hypertensive agent or hypotensive agent. The absence of toxicity and the rapid reversibility of its cardio-vascular effects which are similar to the effects of sodium nitroprusside are important reasons for its use in anesthesia and cardiac intensive care.

Animals↗
PubMedDate not supplied

Mapping of the X-breakpoint involved in a balanced X;12 translocation in a female with mild mental retardation.

Balanced chromosomal abnormalities such as translocations and inversions have been identified in many genetic diseases. Cloning of the breakpoints involved in these abnormalities has led to the identification of the disease-related genes. Recent reports suggest the presence of a mental retardation locus at Xq11-12. We have identified a female patient with a balanced translocation t (X;12) (q11;q15) associated with mild mental retardation. We identified a yeast artificial chromosome spanning the X-chromosome breakpoint by using fluorescent in situ hybridization techniques. A cosmid library of this YAC has been constructed and the search for candidate genes is in progress.

Child↗