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Biomedical subjects

M Paul

Publications and source records attributed to M Paul.

At least 55 records · Page 3Linked to original sources

[Right ventricular arrhythmias].

Right ventricular arrhythmias predominantly occur in young patients with rare cardiac diseases. Underlying cardiac conditions include idiopathic right ventricular outflow-tract tachycardia (RVOT-VT), arrhythmogenic right ventricular cardiomyopathy (ARVC), Brugada syndrome, and postoperative congenital heart disease (i.e. tetralogy of Fallot). According to the underlying cardiac disease, there are significant differences in the diagnostic and therapeutic management and prognosis which is mainly determined by life-threatening ventricular arrhythmia recurrences and sudden cardiac death. To provide optimal treatment for affected patients, a detailed diagnostic evaluation and risk stratification is mandatory. Tailored treatment strategies aim at the suppression or effective termination of recurrent ventricular tachyarrhythmias and prevention of sudden death by antiarrhythmic drug therapy, catheter ablation, and the implantation of cardioverter-defibrillators. This review summarizes the current knowledge on pathogenesis, diagnosis, treatment and prognosis of those conditions that are associated with arrhythmias originating from the right ventricle.

Arrhythmias, Cardiac↗

[Possibilities of computer-assisted navitation in knee para-articular osteotomies].

Osteotomies in the knee region for incipient osteoarthritis in active patients have become increasingly popular in recent years. A computer-guided navigation system should help increase the surgeon's accuracy and lower the risk of intraoperative complications for this technically demanding type of surgery. Furthermore, computer navigation might be a powerful research and educational tool. The technical principles and the clinical implications of this system for knee osteotomies are described in the following article.

Bone Malalignment↗

[Primary cutaneous non T non B CD4+ CD56+ leukemia (2 cases): an original anatomoclinical syndrome].

INTRODUCTION: Non T non B CD4+ CD56+ leukemia is often revealed by cutaneous lesions. We report 2 patients with this disorder who had characteristic anatomoclinical findings. CASE REPORTS: An 81 year-old female and a 75 year-old man presented with erythematous macules which increased in number and progressed to infiltrated plaques and nodules. The lesions became ecchymotic, but the patients remained in good general condition and blood count as well as bone marrow examination were unremarkable. A cutaneous biopsy revealed a lymphomatous mononuclear cell infiltrate. The cells expressed CD4 and CD56, but not CD3. The cutaneous lesions preceded for 10 and 9 months respectively the appearance of overt leukemia and medullar involvement. At this stage, the patients deceased rapidly from their leukemia. DISCUSSION: This is an original anatomoclinical syndrome. The histopathologist must pay attention to the unusual CD4+ and CD3- immunophenotype and search for CD56 expression. The malignant cell responsible for this type of leukemia is now individualized and corresponds to a type II dendritic cell precursor.

Aged↗

[Generalized granuloma annulare and drug-induced immunodeficiency].

BACKGROUND: Granuloma have already been described in the context of immunosuppression. We report six cases of widespread granuloma annulare occurring in patients with drug-induced immunosuppression. CASE REPORTS: There were four women and two men, with mean age of 61 years (35-76). Three patients were treated with chemotherapy for breast (2 cases) and liver cancer. One woman was given chemotherapy for Hodgkin's disease. One had undergone liver transplantation and was given cyclosporine, another was treated with systemic steroids for polyarthritis. All had generalized non-photoexposed granuloma annulare, composed of multiple erythematous papules, sometimes with annular pattern. The lesions were localized on the trunk, legs and arms. Histopathology revealed granuloma annulare in each patient. DISCUSSION: These six cases suggest a relationship between drug-induced immunodeficiency and generalized granuloma annulare. The immune dysregulation induced by the drugs may have been responsible for the formation of granuloma annulare.

Adult↗

A survey of autologous blood transfusion practices in Germany.

This survey was designed to evaluate the use of autologous blood transfusion techniques in Germany in 2000 and to identify how the use of these techniques has changed over the past 5 years. Questionnaires were mailed to the chief anaesthesiologists of 400 randomly selected German hospitals with > or =25 surgical beds. Information was sought about the current and past use of preoperative autologous blood donation (PABD), acute preoperative haemodilution and peri-operative blood salvage. Data were requested for the calendar year 2000. Three hundred and forty-three (86%) completed questionnaires were returned. PABD, haemodilution and peri-operative blood salvage were used by 85, 54 and 67% of respondents, respectively. Thirty-seven per cent of PABD users reported that PABD use declined, 28% reported that it increased and 34% reported that it remained unchanged over the past 5 years. The proportions of those reporting declining vs. increasing use of PABD did not differ significantly (P = 0.09). Sixty per cent of users of haemodilution reported that its use declined, 10% reported that it increased and 29% reported that it remained unchanged over the past 5 years. Sixteen per cent of hospitals that were equipped with cell-washing devices reported that the use of these devices declined, 47% reported that it increased and 37% reported that it remained unchanged over the past 5 years. The results indicate that autologous blood transfusion techniques were widely used in Germany in 2000, with PABD being the most common technique. The use of PABD did not change significantly, the use of haemodilution declined markedly and the use of peri-operative cell salvage increased markedly during the past 5 years before the survey.

Blood Loss, Surgical↗

Preeclampsia is associated with loss of neuronal nitric oxide synthase expression in vascular smooth muscle cells of the human umbilical cord.

AIMS: Umbilical blood vessels are not innervated and regulation of blood flow to the placenta must depend on structural changes and the effect of vasoactive factors. Failure to achieve these adaptations may result in reduced fetoplacental perfusion. The purpose of this study was to determine whether neuronal nitric oxide synthase (nNOS) is expressed in human vascular smooth muscle cells (VSMCs) of the fetoplacental circulation. nNOS has been described as a non-endothelial NOS counterregulating vasoconstriction only in the VSMCs of animal models. Therefore, we investigated nNOS expression in the fetoplacental unit from preeclamptic and healthy pregnancies. METHODS AND RESULTS: We investigated nNOS regulation by immunohistochemistry, Western blotting and reverse transcriptase-polymerase chain reaction analysis. nNOS activity was determined by measuring the conversion of L-3H-arginine to L-3H-citrulline. nNOS expression was revealed only in VSMCs of the human umbilical veins, but not in umbilical arteries. A more direct assessment of nNOS activity showed that a small, but consistent amount of nNOS is present in the denuded media of the umbilical vein. In VSMCs of the umbilical veins during preeclampsia a total loss of nNOS protein expression and a significant decrease in mRNA expression were seen. CONCLUSIONS: Loss of nNOS expression is associated with preeclampsia. It may alter the regulation of blood flow in the fetal and maternal placental vasculature in preeclampsia. However, the impact of NO produced by nNOS on the vascular tone of umbilical veins remains to be elucidated.

Adult↗

Fractures of the calcaneum. A review of 70 patients.

We have assessed the long-term results after operative and non-operative treatment of undisplaced and displaced calcaneal fractures. At a mean of 6.5 years, we reviewed 70 patients with a calcaneal fracture who were divided into four groups: group 1, 18 patients with undisplaced fractures and a normal Böhler's angle (BA) who had been treated non-operatively; group 2, 23 with intra-articular fractures and a BA < 10 degrees who had been treated non-operatively; group 3, 13 with intra-articular fractures and a BA > 10 degrees who had been treated surgically; and group 4, 16 with intra-articular fractures and a BA < 10 degrees who had been treated surgically. The results were assessed by a clinical score considering pain, return to work, return to physical activity, change in shoe-wear and the requirement for subtalar arthrodesis. Patients with undisplaced calcaneal fractures had a good outcome. Those with displaced fractures treated surgically who presented at follow-up with a BA > 10 degrees had a satisfactory functional outcome and those with displaced fractures who had non-operative treatment had a poor outcome. The poorest outcome was consistently seen in patients who were treated operatively without restoration of BA. Open reduction and internal fixation of intra-articular calcaneal fractures can only be expected to benefit those patients in whom nearly anatomical reconstruction is obtained.

Adult↗

Determination of the 8B neutrino spectrum.

We have measured the total energy of the alpha particles following the beta decay of 8B by implanting 8B into a planar silicon surface barrier detector. Calibration was performed using alpha particles following the beta decay of 20Na, similarly implanted. The alpha spectrum is used to infer the 8B neutrino spectrum which is an important input in the interpretation of experiments that detect energetic neutrinos from the Sun. The alpha spectrum reported here is in disagreement with the previous best measurement which used two detectors in coincidence.

Journal Article↗

Persistent bacteremia in the absence of defined intravascular foci: clinical significance and risk factors.

The clinical significance of and the risk factors for persistent bacteremia were assessed in 299 episodes. Persistent bacteremia was defined as at least two positive blood cultures obtained on different calendar days during the same infectious episode. Short-term bacteremia was defined as positive blood cultures solely on the first day of the infectious episode. A total of 4,277 episodes of bloodstream infections were detected, of which 299 episodes (7%) were persistent bacteremia. The following were independent risk factors were for persistent bacteremia: burns, presence of a central vascular catheter, cirrhosis, infections caused by Salmonella spp., polymicrobial infections, and inappropriate empirical antibiotic treatment. Irrespective of the source of infection, the presence of a central vascular catheter was correlated with an increased risk for persistent bacteremia. Mortality among patients with persistent bacteremia was 50%, compared to 35% among patients with short-term bacteremia. Because of the high mortality associated with persistent bacteremia, a thorough search for the source of infection is essential to ensure timely and appropriate therapy.

Adolescent↗

Endothelin-converting enzyme-1 (ECE-1) is a downstream target of the homeobox transcription factor Nkx2-5.

The homeobox transcription factor Nkx2-5 and the zinc metalloprotease endothelin-converting enzyme-1 (ECE-1) are essential for cardiac development. Here, we demonstrate for the first time a functional link between Nkx2-5 and ECE-1. In transiently transfected rat H9c2 cardiomyoblasts, the alternative promoters specific for ECE-1a, ECE-1b, and ECE-1c are activated by Nkx2-5 coexpression. Lack of a consensus sequence for Nkx2-5 binding within the ECE-1c promoter and mutational analyses of Nkx2-5 consensus sequences identified in the ECE-1a and ECE-1b promoters, respectively, reveal an indirect mechanism of activation that is supported by gel shift assays. Furthermore, we have evidence of an additional direct activation mechanism of the ECE-1b promoter by Nkx2-5. With the use of RNase protection assay, Northern blot, and real-time PCR, the activating effect of Nkx2-5 on mRNA expression of ECE-1 isoforms was confirmed in the chromatin context of H9c2 and endothelial EA.hy926 cells, respectively, by stable Nkx2-5 overexpression. The interaction presented in this work provides a possible explanation for distinct phenotypic aspects of patients carrying mutations in the Nkx2-5 gene and may also be of significance for the pathophysiology of heart failure.

Animals↗

Atovaquone-loaded nanocapsules: influence of the nature of the polymer on their in vitro characteristics.

Nanocapsules with atovaquone concentration of 1,000 micrograms/ml were prepared according to the interfacial deposition technique using different polymers: poly- epsilon -caprolactone (PECL), poly(lactic acid) (PLA) and poly(lactic-co-glycolic acid) (PLAGA). The following characteristics of nanoparticles were determined: percentage of encapsulation of atovaquone, percentage of encapsulation of benzyl benzoate (BB), nanoparticle size, nanoparticle wall thickness, suspension pH, and in vitro stability. The different formulations showed similar characteristics: maximal percentage of encapsulation (100%), particle size of approximately 230 nm, neutral pH and wall thickness of approximately 20 nm. The type of polymer used was the main factor influencing stability, in decreasing order: PECL>PLA>PLAGA. No release of atovaquone or benzylbenzoate was noted with PECL nanoparticles over 4 months. Release of atovaquone (25.9%) was found with PLA nanoparticles at 4 months. Release of both atovaquone (18.9%) and benzylbenzoate (54.2%) was noted with PLAGA nanoparticles from the third month, indicating a disruption of the nanoparticle membrane.

Antiprotozoal Agents↗

[The Lazarus phenomenon. Spontaneous return of circulation after unsuccessful intraoperative resuscitation in a patient with a pacemaker].

We present a case of spontaneous recovery after failed intraoperative cardiopulmonary resuscitation in a patient with a cardiac pacemaker. Of the various mechanisms discussed in the literature, that which seems most relevant in our case of a Lazarus phenomenon, is that of impeded venous return in the course of positive pressure ventilation and hypovolemia.With the disconnection of ventilation, passive cardiac filling combined with electrical stimulation due to the cardiac pacemaker may have caused spontaneous myocardial electrical activity. Corresponding to previous authors,we recommend continued monitoring for 10 min after cessation of cardiopulmonary resuscitation. In addition, we propose a further attempt by disconnecting ventilation and external myocardial stimulation in the case of unresponsiveness to resuscitation efforts.

Aged↗

Genetics of arrhythmogenic right ventricular cardiomyopathy--status quo and future perspectives.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a primary myocardial disorder of unknown origin. In recent years, the disease has been recognized as a major cause of ventricular tachyarrhythmias and sudden cardiac death in young patients with apparently normal hearts. Although characteristic structural, imaging and electrocardiographic features are included in a proposed catalogue of diagnostic criteria, the correct diagnosis of ARVC often remains difficult. Much effort has been undertaken to enlarge the knowledge on pathophysiological mechanisms of the disease. The role of molecular genetics for the pathogenesis of ARVC is discussed in the following review. On the basis of linkage analyses in large families affected by ARVC, there is growing evidence for genetic alterations in ARVC, which, in the majority of chromosomal loci (seven) reported so far, follow a Mendelian autosomal-dominant pattern of inheritance with variable penetrance and polymorphic phenotype. Besides this, two autosomal-recessive forms of ARVC are known. These can be differentiated from the autosomal-dominant forms not only in terms of the mode of inheritance but also as to their specific phenotype: patients with Naxos disease exhibit characteristic hair and skin abnormalities and experience a more severe course of disease. Patients with another autosomal-recessive form display the typical but milder signs of ARVC together with opacifications of the crystalline lens. So far, two mutations in cardiac genes responsible for the development of ARVC have been reported. A homozygous two base pair deletion in the gene encoding for the cytoskeletal protein plakoglobin seems to account for the evolution of Naxos disease. The second mutation affecting the cardiac ryanodine receptor gene was found in patients with ARVC-2. Routine genetic testing of patients or relatives with a suspected diagnosis of ARVC is not available at present but may become the future gold standard with potential implications for a better understanding of the pathogenesis and management of the disease.

Abnormalities, Multiple↗

[Aneurysm of the subclavian artery after operatively corrected coarctation of the aorta: 20 years of follow-up and review of the current literature].

We report of long-term follow-up of a combined fusiform aneurysm of the right subclavian artery extending to the thyreocervical trunk (3.2 x 2.8 x 2.2 cm (width x height x depth)) in a 33-year old patient. As a newborn, the clinical diagnosis of an aortic isthmus stenosis was made without need for intervention at this stage. Further development of the child remained unremarkable until the age of eleven years when he experienced dizziness after sporting activities. Due to clinically proven progress, cardiac catheterization was performed and confirmed the initial diagnosis of a juxtaductale stenosis of the aortic isthmus, which was operated thereafter with an end-to-end anastomosis. Furthermore, an aneurysm of the right subclavian artery was revealed. Since then, non-invasive routine follow-up showed no significant worsening of this aneurysm, which extends to the thyreocervical trunk. The patient has been event free and completely asymptomatic. This case report illustrates the more than twenty years of follow-up of an asymptomatic combined fusiform aneurysm of the subclavian artery and thyreocervical trunk and provides a review of the literature on this topic.

Adolescent↗

Optic neuritis complicating west nile virus meningitis in a young adult.

A case of West Nile virus (WNV) infection with meningitis and optic neuritis in a 28-year-old man is presented. The patient had a number of unusual clinical and laboratory findings that broadened the differential diagnosis. The emergence of WNV infection in southern Europe and North America calls for increased awareness of physicians to this clinical entity.

Adult↗