Search PubMed⌕ Search

Biomedical subjects

J Petit

Publications and source records attributed to J Petit.

At least 91 records · Page 5Linked to original sources

Evaluation and management of polyneuropathy: a practical approach.

Disorders of peripheral nerves are commonly encountered by primary health care providers. This article reviews one of the most frequent patterns, that is, polyneuropathy (PN). PN is a common but complex entity. Understanding the pathophysiology of axons, the classification of PN, the biologic targets of toxins and the patterns of PN assist in the diagnosis of PN. The pathophysiology, symptoms, and signs are discussed along with basic steps to be taken in the evaluation, diagnosis, and management. Illustrative case studies are provided. Diagnosis may not be possible in all cases. When the etiology is unknown, ongoing monitoring of the polyneuropathy is emphasized, particularly in acquired processes where the polyneuropathy may be associated with systemic disease. In such instances, care of the client is directed toward symptomatic management.

Adult↗

[Acquired pulmonary vein stenosis after surgery of complex partial anomalous pulmonary venous drainage in an adult. Diagnostic value of transesophageal echocardiography].

Surgical correction of partial anomalous pulmonary venous drainage is difficult and may be complicated by acquired postoperative stenosis at the site of reimplantation of the pulmonary veins in the left atrium. Diagnosis should be made quickly because of the very poor prognosis due to acute pulmonary hypertension. The case described by the authors underlines the value of multiplane transesophageal echocardiography with two-dimensional and Doppler analysis for rapid and accurate diagnosis of this complication.

Adult↗

A randomized comparison of the clinical and hormonal effects of two GnRH agonists in patients with prostate cancer.

OBJECTIVE: The aims of the study were (i) to compared the efficacy of the two long-acting GnRH agonists (GnRHa) triptorelin (Trp) and leuprolide (Leu) in men with prostate cancer and (ii) to assess the pattern of plasma testosterone levels following each injection of GnRHa. PATIENTS AND METHODS: 67 patients referred for prostate cancer not suitable for surgery were randomly allocated to two treatment regimens: 33 patients received 3.75 mg Trp i.m. at 4-week intervals for 3 months and 34 patients were treated with 3.75 mg Leu s.c. at the same rhythm of administration for 3 months. RESULTS: Clinical data at entry and assessed monthly during follow-up did not differ between the two groups. Plasma prostate-specific antigen (PSA) and testosterone were measured before, 24 and 72 h after each injection of GnRHa. During treatment, PSA dropped similarly in both groups. By month 2, testosterone was < 1.0 nmol/l in 77 and 48% of patients treated with Trp and Leu, respectively (p = 0.02). 24 and 72 h after GnRHa injection, 77 (Trp) and 56% (Leu) of patients had testosterone < 1.0 nmol/l (p < 0.05). CONCLUSIONS: The second and third injections of GnRHa were not followed by a significant increase in testosterone. Trp induced a higher decrease in testosterone than did Leu. The implications in terms of survival should, however, be studied in a larger and longer study.

Antineoplastic Agents, Hormonal↗

The dynamic response of feline Golgi tendon organs during recovery from nerve injury.

The dynamic response of tendon organs to isometric contractions of activating motor units has been examined during recovery from nerve crush or nerve transection followed by suture repair. After nerve crush the characteristic response was rapidly restored, although the early and late phases of the dynamic response were altered differentially. Following nerve transection, recovery was much poorer and many responses were abnormal. Normal responses were only observed in a minority of tendon organ-motor unit interactions but every tendon organ studied did respond normally to at least one motor unit, with a range of dynamic sensitivities similar to normal. This suggests that the abnormalities observed reflect changes in the mechanical input to the organ, due to motor unit reorganisation, rather than abnormalities of the transduction process.

Animals↗

Absent pulmonary valve syndrome: surgical treatment and considerations.

BACKGROUND: The operative management of absent pulmonary valve syndrome remains controversial regarding the need for pulmonary valve implantation and remodeling of pulmonary arteries. Moreover, symptomatic infants are considered to have a poor prognosis. This retrospective report summarizes the experience of a single institution. METHODS: Between May 1977 and May 1995, 37 consecutive patients underwent repair of absent pulmonary valve syndrome. Patients were divided into two groups according to age at operation: group A (10 infants less than 1 year old) and group B (27 patients older than 1 year). Mean age at operation was 5 +/- 4 months in group A and 72 +/- 42 months in group B. Initially, repair consisted of ventricular septal defect closure and relief of right ventricular outflow tract obstruction combined with pulmonary valve implantation. More recently, the concept of treatment has evolved with pulmonary arterioplasty without pulmonary valve insertion, except in patients with elevated pulmonary artery pressure. RESULTS: Of the 37 patients, 34 had successful repair. The overall in-hospital mortality rate was 8% (two deaths in group A and one in group B). No hemodynamic data were correlated with operative death. Death was associated with longer extracorporeal circulation time (p = 0.005) and longer aortic cross-clamping time (p = 0.019). In fact, these were clearly related to more complex anatomy (p = 0.001): multiple ventricular septal defects in 1, left pulmonary artery arising from the ductus in another, and left pulmonary artery arising from the aorta in the remainder. Follow-up was available in 22 of the 34 survivors. Mean follow-up time was 30 +/- 47 months in group A and 38 +/- 33 months in group B. All but 1 had no restriction of exercise, and most of them had pulmonary incompetence of Doppler echocardiography. One developed severe exercise intolerance because of pulmonary valve stenosis (xenograft), leading to uneventful reoperation 123 months after initial repair. One infant died suddenly of complete atrioventricular block 3 months after repair. The late mortality rate was 5%. CONCLUSIONS: Surgical treatment of absent pulmonary valve syndrome should include pulmonary arterioplasty to reduce bronchial obstruction, with no need for pulmonary valve insertion. This procedure is feasible and is recommended especially in markedly symptomatic infants.

Case-Control Studies↗

Oligoblastic leukaemia with (8;21) translocation and haemophagocytic syndrome and granulocytic cannibalism.

We report a 47-year-old man with oligoblastic leukaemia (8;21) translocation, phenomenon of cannibalism by granulocytic cells and haemophagocytic syndrome. The patient responded to intensive chemotherapy with disappearance of haemophagocytosis, granulocytic and histiocytic. We conclude that: (1) granulocytic cannibalism and haemophagocytic syndrome can be unusual myelodysplastic features; (2) the oligoblastic leukaemia with presence of cytogenetic abnormalities related to AML in young patients are probably more close to acute leukaemia than to myelodysplastic syndrome.

Chromosomes, Human, Pair 21↗

Feasibility and results of bone marrow transplantation after remission induction and intensification chemotherapy in de novo acute myeloid leukemia. Catalan Group for Bone Marrow Transplantation.

PURPOSE: To evaluate prospectively the feasibility and results of bone marrow transplantation (BMT) after induction and intensification chemotherapy (CT) in patients with de novo acute myeloid leukemia (AML). PATIENTS AND METHODS: A total of 159 patients less than 51 years of age were treated. Induction CT consisted of daunorubicin 60 mg/m2 for 3 days, cytarabine (ARA-C) 100mg/m2 for 7 days, and etoposide 100 mg/m2 for 3 days. The first intensification therapy included mitoxantrone 10 mg/m2 for 3 days and ARA-C 1.2 g/m2 every 12 hours for 4 days. Amsacrine (100 or 150 mg/m2 for 3 days) and ARA-C (1.2 g/m2 every 12 hours for 2 or 4 days) were given as the second intensification therapy. Depending on the availability of a human leukocyte antigen (HLA)-identical sibling, the intention of treatment after CT was allogeneic BMT (allo-BMT) or autologous BMT (ABMT). RESULTS: Complete remission (CR) was obtained in 120 patients (75%) and partial remission (PR) in 11 (7%), while 15 patients (10%) were refractory and 13 (8%) died during induction. There was a trend for better leukemia-free survival (LFS) at 4 years for patients assigned to the ABMT group (50% +/- 6%) compared with the allo-BMT group (31% +/- 7%) (P = .08). This difference in LFS reached statistical significance when considering only transplanted patients (63% +/- 3% at 4 years after ABMT and 38% +/- 11% after allo-BMT, P = .02). The favorable results in patients who received ABMT (no toxic deaths and 37% +/- 7% probability of relapse at 4 years) contrast with the poor outcome of allografted patients (11 patients with transplant-related mortality). CONCLUSION: Our study reflects the difficulties in the completion of a therapeutic strategy that include BMT and suggests that intensification before BMT may be useful in the setting of ABMT, but this approach was associated with a high mortality rate in allo-BMT patients.

Acute Disease↗

[Rare tumors of the prostate or seminal vesicles. Report of a case of leiomyosarcoma].

An unusual case of leiomyosarcoma of the prostate presented as a recurrent pelvic cystic mass. Prostatic sarcoma are rare in adults with a poor prognosis. It is often difficult to determine a definite origin. The authors reviewed the differential diagnosis with pseudosarcoma, inflammatory fibrosarcoma and others rare tumors of the prostate and the seminal vesicle.

Diagnosis, Differential↗

Allogeneic peripheral blood progenitor cell transplantation: analysis of short-term engraftment and acute GVHD incidence in 33 cases. allo-PBPCT Spanish Group.

The results of 33 allogeneic peripheral blood progenitor cells transplants (allo-PBPCT) in adult patients with hematologic malignancies were analyzed in a retrospective and multicenter study. In 21 of 33 cases (63%) the disease was refractory or in advanced stage and eight of the 33 cases (24%) were second transplants after relapse. Donors were treated with a median of 10 (4-16) micrograms/kg/day of rhG-CSF subcutaneously for 5-7 days. Three required a central venous line for harvesting. Peripheral blood leukapheresis product contained a median of 5.9 (1.8-13) 10(6)/kg CD34+ cells and a median of 309.5 (153-690) 10(6)/kg CD3+ cells. After a myeloablative regimen, all patients received PBPC from HLA-identical donors as the sole source of progenitor cells. Cyclosporin A (CsA) alone (n = 2), CsA and steroids (n = 9), and CsA and methotrexate (MTX) (n = 22) were used for GVHD prophylaxis. Growth factors post-transplant were given to 11 patients (33%). The median follow-up of the patients was 3 months. Actuarial median day for hemopoietic recovery was: neutrophils to >0.5 (>1) x 10(9)/l, day 14 (15); platelets to >20 (>50) x 10(9)/l, day 14 (21). The quantity of CD34+ cells infused did not significantly affect the engraftment kinetics, from a starting cutoff of 2.5 x 10(6)/kg. The speed of neutrophil recovery seemed to be influenced strongly by using rhG-CSF post-transplant and marginally by the type of GVHD prophylaxis. Actuarial probability for grade II-IV acute GVHD of the whole group was 37% (95% Cl, 20-54%).

Actuarial Analysis↗

Mobilization of peripheral stem cells with intensive chemotherapy (ICE regimen) and G-CSF in chronic myeloid leukemia.

Seventeen patients with Philadelphia (Ph) chromosome-positive chronic myeloid leukemia (CML) were treated with the ICE regimen plus G-CSF with the aim of mobilizing and collecting Ph-negative peripheral stem cells (PSC) in the setting of an autotransplant program. Fifteen patients had CML in first chronic phase (CP), and two in accelerated phase (AP). Three patients had been previously treated with interferon alpha 2a (IFN). Twelve patients underwent leukaphereses and a mean of 4.7 x 10(8)/kg mononuclear cells were obtained. Four CP patients did not show a significant mobilization peak of CD34+ cells and leukapheresis was not performed; finally, one patient died before apheresis could be performed. Six of the 12 who underwent leukaphereses obtained more than 1.0 x 10(6)/kg CD34+ cells. Eight of the 12 mobilized patients (67%) obtained a major cytogenetic response, including two complete and six partial; in the remaining four patients minimal or absent cytogenetic responses were observed. A higher rate of Ph purging was obtained in patients mobilized early or showing residual Ph-negative cells before mobilization, even if they were in AP. Infectious complications were frequent with a 38% rate of bacteremia recorded and one case of pulmonary aspergillosis resulting in a toxicity similar to that occurring in acute myeloid leukemia-induction chemotherapy. The ICE regimen can promote 'in vivo' purging of the Ph+ cells in 67% of CML mobilized patients (8/12). Failure of mobilization occurs in 65% of patients (11/17), mainly because of poor CD34+ cell yield.

Adult↗

The static sensitivity of tendon organs during recovery from nerve injury.

An investigation has been carried out into the physiological properties of tendon organs and their interactions with motor units following two types of nerve injury: nerve crush and nerve transection followed by suture repair. Recovery from nerve crush was very successful: 6 weeks after the injury 60% of the tendon organ-motor unit interactions (n = 62) evoked normal or near-normal patterns of afferent discharge but with reduced firing rates. After 10 weeks of recovery 81% of the interactions (n = 43) were normal. The main abnormality observed was a phasic-only pattern of discharge. The overall reductions in firing rate during early recovery may be attributable to the lower contractile forces generated by the reinnervated muscle units, while the phasic-only responses may also represent immaturity of the transduction mechanism of the regenerated afferent axons. Following nerve transection the quality of recovery was much lower and a range of abnormal, as well as normal patterns of response were observed. For all the afferents studied, both types of response were recorded, suggesting that although there may be changes in the sensitivity of the afferents to muscle contraction, the abnormal responses more probably reflect changes in the form of the mechanical input rather than abnormalities of the transduction process.

Animals↗

The dynamic response of Golgi tendon organs to tetanic contraction of in-series motor units.

Golgi tendon organs (TOs) display a dynamic response related to the rate of tension development by the motor units (MUs) which activate each TO. When several MUs are activated together the response increases non-linearly with respect to tension. The dynamic response has been re-examined by recording the responses of TOs, in the adult cat, to tetanic, isometric contractions of one or more MUs and has been found to comprise two components: for each MU-TO pair the instantaneous frequency between the first two impulses of the response was linearly related to the rate of rise of the tension, the slope of the relationship being greatest for the slow units. Similarly, when activating MUs were stimulated together, the relationships between frequency and the initial rate of tension rise were linear. When the relationships were expressed in terms of relative tension rate the organs were found to be most strongly activated by the IIb muscle fibres, the responsiveness at the level of the whole muscle being reduced by unloading effects. The later component of the response showed an exponential relationship between discharge frequency and rate of tension development, the slope of the relationship between frequency and the logarithm of tension rate being independent of MU size. Although absolute tension increases during a contraction, this did not appear to impinge on the response which was dominated by the dynamic parameters of the contraction.

Animals↗

[Extraction of intravascular foreign bodies].

OBJECTIVE: Loss or displacement of foreign material within the cardiovascular system is not an uncommon event. Foreign bodies include fragments of diagnosis equipment, ruptured catheters or malpositioned or displaced intravascular prostheses. The incidence has increased with the development of endovascular catheterism and raises the problem of extraction. METHODS: We report our experience with percutaneous extraction of intravascular foreign bodies. RESULTS: There were 56 cases. Percutaneous extraction was successful in 53. In 11 cases, the procedure was carried out during a catheterism procedure and in the others the initial event had occurred earlier. The delay to extraction varied from a few hours to several years. CONCLUSION: Percutaneous extraction of intravascular foreign bodies should be attempted before surgical removal, an often difficult high-risk procedure. The literature does not provide data on the frequency of intravascular foreign bodies.

Adolescent↗

[Right posterolateral thoracotomy in the treatment of of simple and isolated lesions of the heart].

The right posterolateral thoracotomy approach was used in 13 young girls aged from 1 to 8 years for open heart repair of atrial septal defect (ostium secundum and primum) and ventricular septal defect, without morbidity nor mortality. Neither the thoracotomy scar nor impaired growth of the mammary gland were visible. This approach is considered as safe as median sternotomy for open heart repair of isolated and simple cardiac defects, in prepuberty young females.

Child↗

Transposition of the great arteries [S,D,L]. Pathologic anatomy, diagnosis, and surgical management of a newly recognized complex.

The transposition of the great arteries [S,D,L] complex is delineated for the first time from the anatomic, diagnostic, and surgical standpoints in this study of 26 cases: 16 surgical and 10 postmortem. Transposition of the great arteries with situs solitus of the viscera and atria (S), D-loop ventricles (D), and L-transposition (L) was characterized by six additional interrelated anomalies that largely determined surgical management: (1) ventricular septal defect, usually conoventricular, in 96%; (2) malalignment of the conal septum, typically leftward and posteriorly, in 80%; (3) right ventricular hypoplasia in 50%; (4) pulmonary outflow tract stenosis in 27%; (5) ventricular malposition, such as superoinferior ventricles, in 23%; and (6) absent left coronary ostium resulting in "single" right coronary artery in 23%. Complete surgical repair was done in 81% of the surgical patients with a 12.5% hospital mortality rate and no late deaths. When there was no pulmonary outflow tract stenosis and intracardiac anatomy was uncomplicated, we undertook anatomic repair before 1 month of age. However, when pulmonary outflow tract stenosis coexisted, complete repair was deferred until after age 1 year, our currently preferred operation being the REV procedure (réparation a l'etage ventriculaire). When complex intracardiac anatomy precluded biventricular repair, a palliative procedure was performed in 19% without mortality. Hence, this experience indicates that surgical management of patients with the transposition of the great arteries [S,D,L] complex is feasible.

Child↗