Biomedical subjects

D Leblond

Publications and source records attributed to D Leblond.

6 recordsLinked to original sources

PubMed2001

Unit dose sampling and final product performance: an alternative approach.

This article documents a proposed plan for validation testing for the content uniformity for final blends and finished solid oral dosage forms (SODFs). The testing logic and statistical justification of the plan are presented. The plan provides good assurance that a passing lot will perforin well against the USP tablet content uniformity test. The operating characteristics of the test and the probability of needing to test for blend sampling bias are reported. A case study is presented.

Algorithms↗

PubMed1998

Respiratory involvement in relapsing polychondritis. Clinical, functional, endoscopic, and radiographic evaluations.

Although respiratory involvement occurs in 50% of patients with relapsing polychondritis (RP) and augurs a poor prognosis, few previous studies have provided complete descriptions of respiratory tract involvement. For this reason, we investigated the respective role of clinical, functional, endoscopic, and radiographic (computed tomography [CT]) examinations in 9 consecutive patients with RP and lower respiratory tract localization. All exhibited cough, dyspnea, and wheezing. Eight had a nonreversible obstructive pattern with a marked decrease of the maximal flow ratio at 75% and 25% of vital capacity. Rotman functional criteria were evaluated to differentiate upper from lower respiratory tract involvement; they were consistent with the results of other examinations in 4/9 cases. Endoscopic examination showed moderate to severe inflammation in 8/9 patients; tracheal stenosis was present in 6/9 patients, bronchial stenosis in 4/9 patients, and tracheal collapse in 7 cases. CT showed tracheal stenosis in 8/9 patients (diffuse, 7; localized, 1) and bronchial stenosis in 6/9 patients. Tracheobronchial wall thickening and/or calcifications were observed in 7 cases. Clinical symptoms are of poor specificity for defining respiratory involvement precisely, although degree of dyspnea is correlated to the decrease in forced expiratory volume in 1 second (FEV1). Functional criteria were helpful in evaluating the obstructive ventilatory defect but did not differentiate, in most cases, the respective part of lower and upper respiratory involvement when using Rotman criteria. Compared to CT findings, endoscopic examination failed to identify tracheal and bronchial stenosis and tracheal wall alterations at an early stage of the disease. In our series CT appears to be a reliable method to identify tracheal and bronchial involvement and can be repeated safely during the course of the disease.

Adult↗

PubMed1996

Percutaneous vertebroplasty for osteolytic metastases and myeloma: effects of the percentage of lesion filling and the leakage of methyl methacrylate at clinical follow-up.

PURPOSE: To determine whether the percentage of vertebral lesion filling and the leakage of methyl methacrylate have any clinical significance at follow-up. MATERIALS AND METHODS: Forty percutaneous vertebroplasties were performed for metastases (30 cases) and myeloma (10 cases) in 37 patients. A computed tomographic scan was obtained 1-8 hours after methyl methacrylate injection and was used to assess the percentage of lesion filling by methyl methacrylate and the leakage of methyl methacrylate into the epidural tissues, neural foramina, intervertebral disks, venous plexus, and paravertebral tissue. The results were correlated with those obtained at clinical follow-up. RESULTS: Partial or complete pain relief was sustained in 36 of 37 patients. Pain relief was not proportional to the percentage of lesion filling. Clinical improvement was maintained in most patients. The 15 epidural leaks, eight intradiskal leaks, and two venous leaks of methyl methacrylate had no clinical importance. Two of eight foraminal leaks produced nerve root compression that required decompressive surgery. One of 21 paravertebral leaks produced transitory femoral neuropathy. CONCLUSION: Pain relief can occur despite insufficient lesion filling. In most patients, intradiskal and paravertebral leaks of cement had no clinical importance.

Bone Cements↗

PubMedDate not supplied

Percutaneous vertebroplasty: state of the art.

Vertebroplasty is an effective new radiologic procedure consisting of the percutaneous injection of a biomaterial, usually methyl methacrylate, into a lesion of a vertebral body. This technique allows marked or complete pain relief and bone strengthening in most cases. The principal indications for vertebroplasty are osteolytic metastasis and myeloma, painful or aggressive hemangioma, and osteoporotic vertebral collapse with debilitating pain that persists despite correct medical treatment. Radiography and computed tomography must be performed in the days preceding vertebroplasty to assess the extent of vertebral collapse, the location and extent of the lytic process, the visibility and degree of involvement of the pedicles, the presence of cortical destruction or fracture, and the presence of epidural or foraminal stenosis caused by tumor extension or bone fragment retropulsion. Leakage of methyl methacrylate during vertebroplasty may cause compression of adjacent structures and necessitate emergency decompressive surgery; thus, the procedure should be performed only in a surgical center. The decision to perform vertebroplasty should be made by a multidisciplinary team because the choice between vertebroplasty, surgery, radiation therapy, medical treatment, or a combination thereof depends on a number of factors. Radiologists need to be aware of the various indications for vertebroplasty and of potential future developments and applications of the procedure.

Hemangioma↗

PubMedDate not supplied

Therapeutic percutaneous injections in the treatment of malignant acetabular osteolyses.

Percutaneous injection of methylmethacrylate or ethanol may provide marked pain relief or bone strengthening in patients with malignant acetabular osteolyses who are unable to tolerate surgery. Injection of methylmethacrylate is usually indicated when osteolysis involves the weight-bearing part of the acetabulum (ie, the acetabular roof); in all other cases, ethanol injection is preferred. Ethanol and methylmethacrylate injections may be performed together if both weight-bearing and nonweight-bearing parts of the acetabulum are involved or extensive soft-tissue involvement is present. Moreover, these injections may be performed prior to radiation therapy, which complements their action due to similar but delayed effects on pain, or after radiation therapy that failed to relieve pain or in cases of local recurrence. Radiography and computed tomography must be performed prior to therapeutic percutaneous injection to assess the location and extent of the lytic process, the presence of cortical destruction or fracture, and the presence of soft-tissue involvement. Fever and transitory worsening in pain may occur secondary to inflammatory reaction in the hours following injection; however, these side effects usually resolve spontaneously within 1-3 days. The decision to perform therapeutic percutaneous injections should be made by a multidisciplinary team because the choice between this option and alternative methods of treatment depends on several factors including the location of the lesion, the local and general extent of the disease, the pain and functional disability experienced by the patient, and the patient's state of health and life expectancy.

Acetabulum↗

PubMedDate not supplied

[Normal and pathological aspects of the glenoid labrum in opaque arthro-scanner].

The morphology of the glenoid labrum was studied by CT arthrography in 88 patients. These were divided in 2 groups. In the first group, the patients underwent CT arthrography for a clinical instability of the shoulder. The second group was the reference group to study the morphology of the glenoid labrum, it included patients with rotator cuff tears or other pathology of the shoulder, without clinical instability. We described the normal labrum which presents important morphologic variations. Its study may be difficult because of the proximity of capsular structures of the shoulder, mainly the gleno-humeral ligaments. The normal variants and the pathologic aspects of the labrum were studied: the clefts, tears and degenerative phenomenous. The cleft aspect was studied comparatively in the instable population and in the reference population.

Arthrography↗