Search PubMed⌕ Search

Biomedical subjects

M Abbar

Publications and source records attributed to M Abbar.

At least 37 records · Page 2Linked to original sources

[Treatment of ureteral calculi with rigid ureteroscopy. Report of 67 cases].

PURPOSE: To evaluate the results obtained by rigid ureteroscopy to treat ureteral calculi. MATERIALS AND METHODS: Between May 1998 and September 2000, 63 patients underwent 67 rigid ureteroscopies (URS) with three endoscopic retreatments and one bilateral URS, for 48 distal, ten mid and nine proximal ureteral calculi. RESULTS: After URS 77.6% of the patients were free of the stones. Success rate was respectively 85.4%, 60% and 55.5% in distal, mid and proximal uretero. Morbidity was 10.4% and there have been one stricture treated by endoscopy. CONCLUSION: Our series demonstrates that rigid URS is safe and effective procedure to treat distal, ureteral calculi. Thus, it should be considered a treatment of choice for distal ureteral calculi.

Adult↗

Suicide attempts and the tryptophan hydroxylase gene.

Tryptophan hydroxylase (TPH) is the rate-limiting enzyme of serotonin synthesis. In this case-control study, we investigated whether the TPH gene was a susceptibility factor for suicidal behavior. Seven polymorphisms spanning the entire gene were studied in a case-control study including 231 individuals who had attempted suicide and 281 controls. Significant associations were found between variants in introns 7, 8 and 9 (chi(2) = 11.2, df = 1, P< 0.0008 for the allele distribution; these loci are in complete linkage disequilibrium) and in the 3' noncoding region (chi(2) = 30.94, P = 0.0014) and suicide attempt. The association was strongest for subjects who had attempted suicide by violent means and who had a history of major depression. No significant association was observed between suicide attempts and polymorphisms in the promoter, intron 1 and intron 3. The results presented here, and those of previous studies, suggest that a genetic variant of the 3' part of the TPH gene may be a susceptibility factor for a phenotype combining suicidal behavior, mood disorder and impulsive aggression.

Adult↗

Association between violent suicidal behavior and the low activity allele of the serotonin transporter gene.

There is compelling evidence that serotonin system dysfunction is associated with certain behavioral disorders, such as suicidal behavior and impulsive aggression. A functional polymorphism in the promoter region of the serotonin transporter gene (5-HTTLPR) was recently identified and the presence of the short allele found to be associated with a lower level of expression of the gene, lower levels of 5-HT uptake, suicidal behavior and anxiety-related traits. We genotyped 51 West European Caucasians who had made violent suicide attempts and 139 controls of the same ethnic origin, with no history of suicidal behavior. The frequencies of the S allele and the SS genotype were significantly higher in the violent suicide attempters than in the controls. The odds ratio for the SS genotype vs the LL genotype was 3.63 (95% CI (1.27--10.40)). This suggests that a change in expression of the gene encoding the 5-HT transporter may be involved in violent suicidal behavior.

Adult↗

[Syringocele: report of 2 cases].

Cowper's syringocele, dilatation of bulbo-urethral glands, is a rare disease, usually congenital. The authors report two cases of perforated syringocele and analyse the clinical, radiological and therapeutic aspects of this disease.

Adult↗

[Renal lymphangioma].

The authors report the case of a 39-year-old man presenting with renal colic attributed to a renal tumour diagnosed on CT scan. Treatment consisted of total nephrectomy in the absence of a definitive intraoperative histological diagnosis of renal lymphangioma. Renal lymphangioma is a rare benign tumour, probably derived from a congenital malformation of the lymphatic system. Medical imaging has certain limits for the diagnosis which can be confirmed by renal needle biopsy. Treatment must always be as conservative as possible. The clinical course is always favourable.

Adult↗

[Venlafaxine withdrawal syndrome: report of six cases and review of the literature].

INTRODUCTION: Venlafaxine is an antidepressant that selectively inhibits serotonin reuptake and is a norepinephrine inhibitor. Withdrawal syndromes can occur after abrupt drug discontinuation of long-term regimens. EXEGESIS: We report six cases of withdrawal symptoms after venlafaxine discontinuation. CONCLUSION: Physicians must be aware of the frequency, rapidity and potent severity of these withdrawal syndromes.

Adult↗

[Voluntary lithium salt poisoning; risks of slow release forms].

Lithium carbonate has been an invaluable drug in the treatment of manic-depressive illness. At the present time slow-release forms are available for better stability of circulating drug level with one daily take. However the better stability of lithiemia with these forms has to be balanced with a higher toxic risk in cases of lithium carbonate overdose because of continuous release. We report three cases of overdose with sustained-release lithium salts reaching life threatening complications. Two hemodialysis sessions were necessary to control plasma lithium levels. In two cases, lithiemia rebond was observed after the first hemodialysis session, and was associated with severe neurological disorders. This publication pointed out the therapeutic rule of at least two hemodialysis sessions in cases of severe slow release lithium carbonate salts intoxication.

Adult↗

Overdose with sustained-release lithium preparations.

Acute lithium intoxication is potentially lethal. Compared to conventional lithium preparations, sustained-release lithium formulations present specific problems for medical practice in the case of overdose. We report a case of intoxication with 8000 mg of sustained-release lithium carbonate preparation (Teralithe 400 LP(R)). Twenty-five hours after the ingestion, the patient was still asymptomatic, despite a serum level in the toxic range. After comparison of this case with reports found in the Medline database, we consider the clinical management of such cases.

Adult↗

Clozapine and metabolite concentrations during treatment of patients with chronic schizophrenia.

Results presented in this article are focused on the variability in pharmacokinetics. The purpose of this study was (1) to investigate intra- and interindividual variabilities of pharmacokinetic parameters of clozapine and its two main metabolites in plasma after multiple oral administration in 8 chronic schizophrenic patients (Study 1) and (2) to gain more information regarding plasma concentrations of these drugs after multiple doses in a group of 25 treatment-responsive patients (Study 2). Patients were treated with clozapine in fixed daily doses (given every 8-12 hours) between 200 and 900 mg. Plasma drug concentrations were determined by high-performance liquid chromatography. The mean volume of distribution and the total plasma clearance of clozapine, uncorrected for bioavailability, were 7 L/kg and 40.5 L/h, respectively. The terminal elimination half-lives averaged 10.5 hours for clozapine, 19.2 hours for norclozapine, and 8.6 hours for the N-oxide metabolite. Significant relationships were observed between clozapine and norclozapine (or clozapine N-oxide) plasma concentrations. Large inter- and intrapatient variations in pharmacokinetics were observed. Clozapine was generally well tolerated by the patients, with sedation, hypersialorrhea, and tiredness as the most common side effects encountered.

Adult↗

Multiple-dose pharmacokinetics of clozapine in patients with chronic schizophrenia.

The pharmacokinetic parameters of clozapine and its two main metabolites, N-desmethylclozapine (norclozapine, active metabolite) and clozapine N-oxide, were evaluated, after oral administration, in 19 patients with chronic schizophrenia. Plasma and red blood cell (RBC) drug concentrations were determined by high-performance liquid chromatography. Large interpatient variations in pharmacokinetic parameters of clozapine and its two metabolites were observed. Plasma clozapine concentration peaked, on average, at 2.3 hours. The mean volume of distribution and the total plasma clearance, uncorrected for bioavailability, were 6 L/kg and 38 L/hr, respectively. The terminal elimination half-lives averaged 7.6 hours for clozapine, 13 hours for norclozapine, and 7 hours for the N-oxide metabolite. The mean RBC/plasma concentration ratios were 23, 61, and 81% for clozapine, N-desmethylclozapine, and clozapine N-oxide, respectively. From RBC concentration data, the mean elimination half-lives were 7.6 hours for clozapine, 16 hours for N-desmethylclozapine, and 8 hours for the N-oxide metabolite. The average value for blood clearance of clozapine was 54.7 L/hr. Significant correlations were observed between dose and maximum plasma concentrations and between dose and area under the curve concentrations; these results suggested linear steady-state pharmacokinetics over the range of concentrations studied.

Adolescent↗

Manic depressive illness and tyrosine hydroxylase gene: linkage heterogeneity and association.

Several studies have implicated the tyrosine hydroxylase (TH) locus within the 11p15 region in susceptibility to manic depressive illness (MDI). This possibility was further investigated by both parametric (lod score) and nonparametric (affected-pedigree-member and a case-control study) methods of analysis in 11 French MDI families and in a sample of 200 unrelated subjects. Both types of analyses corroborate the implication of this locus, and positive lod scores were obtained in two families, which most likely reflects genetic heterogeneity. Statistical analyses were also performed including available data from published reports. These analyses, which allowed for genetic heterogeneity, substantiated our findings. The combined maximum lod score for all the families studied was 3.68 at theta = 0.00 (number of families: 36) assuming heterogeneity (alpha = 15%, P = 0.01). Taken together these results converge to suggest that the risk factors for MDI lie in the 11p15 region with TH being the most likely candidate gene.

Alleles↗

[Epidemiologic and molecular genetic of suicidal behavior].

The current understanding of suicidal behaviors is that such behaviors are multidetermined and mental state and trait related. Genetic factors appear to be of great importance, as suggested by the findings of family, twin, and adoption studies. Whether these genetic factors are similar to those involved in the susceptibility to psychiatric disorders closely related to suicidal behavior (eg, manic depressive illness, schizophrenia or substance use disorders) is yet unknown. However, a genetic factor of susceptibility to suicide, independent or additive to the genetic transmission of the psychiatric disorders that are related to suicidal behavior, is strongly suggested by the data of the Copenhagen adoption study and a study of Amish families. Recently, new approaches have been proposed to identify the genetic component of such complex traits. Association studies between genetic markers and a disease phenotype has been successfully applied to several complex disease such as essential hypertension. One candidate gene for suicidal behaviors is the tryptophane hydroxylase (TPH) gene which is the first and possibly rate-limiting enzyme of the metabolic pathway for serotonin. Indeed, altered serotoninergic function in both completed suicide and suicide attempt has been one of the most replicated findings in modern biological psychiatry. In our knowledge, only two studies have tested the association between suicide attempt and the TPH gene and their authors found negative results. Despite these negative results, association studies that use candidate gene remain one of the methods of choice for studying the genetic component of suicidal behaviors.

Depressive Disorder↗

[Panic disorder and panic attack].

Panic disorder first appeared as a specific diagnostic entity in 1980, in the third Edition of "Diagnostic and Statistical Manual of Mental Disorders" (DSM III). The classical anxiety neurosis was divided into two separate entities: panic disorder and generalized anxiety disorder, whose major criteria for distinction was based, in a simplified manner, on the presence or absence of panic attacks in the patient's history. Validity of the concept of panic disorder as a clinical and autonomous entity is now widely accepted. It is based on numerous epidemiological, phenomenological, biological, genetic and therapeutic studies that have established, that panic disorder may be clearly distinguished from other anxiety and mood disorders. However, this disorder still has unknown aetiology and criteria for definition remain purely clinical. Controversies as regards the validity of diagnostic criteria for panic disorders may account for its successive definitions in the DSM III-R, then in the DSM IV. In fact, in contrast to the definition of panic attacks that has remained practically constant, panic disorder was initially defined by the recurrence of panic attacks. It is now considered by the authors of the DSM IV as a disorder characterized by a chronic anxiety, focused on the risk for panic attacks showing symptoms evocative of autonomic dysregulation. In the DSM IV, panic attack is now considered as a syndrome which is not specific for panic disorder. Panic disorder may be diagnosed in a patient who has suffered from recurrent panic attacks, provided that one at least of the latter have been associated with one of the following symptoms: persisting fear from other panic attacks; concerns about possible implications of panic attacks or their consequences; major behavioural changes related to the attacks. Evolving positions of the successive authors of the DSM contrast with more conservative attitudes of the authors of the CIM 10, who still consider agoraphobia as a key symptom. Whatever the issues of these definitions, it must be kept in mind that panic disorder is a severe syndrome, and leads to major suffering and significant impairment of the patients' quality of life as well as their social life and interpersonal relationships. Comorbidity with depressive and addictive disorders is frequent, and panic disorder is considered by numerous authors as a risk factor for suicide. Due to the severity of panic disorder, its frequency and the fact that it is too often undiagnosed (although there are effective therapeutic strategies), efforts are fully warranted, so that patients may benefit from early diagnosis and adequate treatment.

Anxiety Disorders↗

Suicidal behaviors and the tryptophan hydroxylase gene.

BACKGROUND: To determine whether the tryptophan hydroxylase gene (ie, the gene that codes for the rate-limiting enzyme in the metabolic pathway of serotonin) may be a susceptibility factor for suicidal behavior. METHODS: Genotypic and allelic frequencies at a polymorphic Ava II restriction site were revealed with the use of the complementary DNA tryptophan hydroxylase probe C2-38 in 62 suicide attempters. The psychiatric characteristics of these suicide attempters were determined using the Schedule for Affective Disorders and Schizophrenia-Lifetime version with modification for the study of anxiety disorders, and these characteristics were compared with those in 52 healthy controls. RESULTS: No association between tryptophan hydroxylase and suicidal behavior was detected. CONCLUSION: The tryptophan hydroxylase gene was not a susceptibility factor for suicidal behaviors in the group of suicide attempters in this study.

Alleles↗