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Biomedical subjects

P Ledoux

Publications and source records attributed to P Ledoux.

At least 19 recordsLinked to original sources
PubMed2002

Single injection digital block: comparison between three techniques.

INTRODUCTION: Regional anesthesia of a single finger is commonly achieved by the traditional ring block. The major drawback of this technique is the need for at least two painful injections in the digit. Single injection techniques have been described. A comparison of their results could help health professionals select the most appropriate technique. MATERIAL AND METHODS: A prospective randomized study was designed to compare three techniques in term of patient tolerance, distribution of anesthesia and efficiency: the modified transthecal digital block, the subcutaneous digital block and a combination of the two. Digits were randomized in three groups (n = 30). Blocks were performed by a single investigator. A visual analogic scale was used to evaluate pain associated with the injection. Prick-testing was used to evaluate anesthesia at the volar and dorsal aspects of the phalanxes. Statistical analysis of the results was performed. RESULTS: All techniques allowed surgery to be performed without complementary injection most of the time (25/30). The dorsum of the proximal phalanx, however, was unpredictably included in the anesthetized territory. The highest rate of full digital block was achieved with the combined technique. DISCUSSION: The least invasive of equally effective techniques should be considered as the first choice. The subcutaneous single injection digital block is safe, efficient and easy to perform. It allows treatment of all conditions on the volar aspect of the finger and on the dorsal aspect of the distal and middle phalanxes. For surgery on the dorsal aspect of the proximal phalanx, a supplementary dorsal block should be used.

Anesthesia, Conduction↗
PubMed2002

Percutaneous Herbert screw fixation for fractures of the scaphoid: review of 30 cases.

INTRODUCTION: The purpose of this study was to evaluate the results of percutaneous fixation of undisplaced or minimally displaced fractures of the scaphoid using the first generation Herbert screw in terms of union, functional results and scaphoid mobility. METHODS: 30 of the 50 patients operated on in our department between 1995 and 2000 were available for evaluation by an independent observer. Wrist mobility, grip strength and key pinch were measured. Scaphoid mobility was evaluated by measuring radioscaphoid angles in flexed and extended positions on dynamic X-rays. RESULTS: The union rate was comparable to that achieved by non-operative management (90%). Resumption of professional activities was possible long before bony union because immobilization was short. Grip strength, wrist and scaphoid mobilities were comparable to the controlateral sides except for scaphoid flexion. Persistent symptoms were found in 30% of the patients despite union of their fracture. DISCUSSION: Our results demonstrate that percutaneous stabilization of undisplaced or minimally displaced fractures of the scaphoid preserves the mobility of the wrist and minimally alters the normal dynamics of the carpus. The duration of work inability is short.

Adult↗
PubMed2001

Atypical mycobacterial infections of the hand: report of eight cases and literature review.

INTRODUCTION: Atypical mycobacteria are an uncommon cause of hand infections in immunocompetent patients. Diagnosis is often delayed, with consequent increased morbidity. Better awareness would allow earlier diagnosis and treatment. MATERIAL AND METHODS: Eight patients with atypical mycobacterial hand infections treated in our department over a 21 year period have been retrospectively identified. Their charts have been searched for the general characteristics of these infections, treatment and outcome. Our findings have been compared to the data collected from a literature review. RESULTS: These pathogens have caused soft tissue infections in otherwise healthy patients. Clinical signs were those of chronic finger or wrist synovitis or skin granulomas. Carpal tunnel syndrome was a common finding. Diagnosis relied on surgical biopsy. Germ identification required specific incubation temperature and media. Antibiotics and synovectomy have been the mainstay of therapy. DISCUSSION: In a patient with achronic, relapsing, superficial or deep skin infection or tenosynovitis, aquatic and farm exposures are important anamnestic keys to diagnosis. Extensive synovectomy is both diagnostic and therapeutic. Specific cultures should be ordered without delay. Oral pharmacotherapy should be initiated upon clinical suspicion.

Adult↗
PubMed2001

Modifications to the mechanical behavior of the wrist after fracture of the scaphoid. Modeling by finite element analysis.

Although based on their long-term clinical evolution there appeared to be no doubt that fractures of the scaphoid modify the mechanical behavior of the carpus, the mechanisms of these modifications have not yet been investigated. This study based on finite element analysis provides insight into the sequence behind the onset of arthritis of the wrist, highlighting the existence of pressure peaks at the nonunion and at the midcarpal interface (scaphoid-capitate and lunate-capitate). This evidence explains the clinical evolution of nonunions of the scaphoid. Our study indirectly demonstrates the role played by the scaphoid within the wrist as a force transmission column. The use of finite element analysis for the modeling of simple or complex osteoarticular systems may prove to be a highly useful tool for the understanding of these mechanisms.

Biomechanical Phenomena↗
PubMed1999

A novel developmentally regulated gene in lung mesenchyme: homology to a tumor-derived trypsin inhibitor.

We used differential display-PCR (DD-PCR) to identify glucocorticoid-inducible genes that regulate lung development in late gestation. DD-PCR, a method to screen for differentially expressed genes, is based on a comparison of mRNAs isolated from a subset of two or more cell populations by analysis of RT-PCR products on DNA-sequencing gels. We isolated cDNA probes representing mRNAs expressed in primary cultures of rat lung fibroblasts, but not in epithelial cells, on fetal day 20. A day 20 glucocorticoid-treated fibroblast cDNA library was screened with a single probe to isolate the 3.1-kb cDNA late-gestation lung 1 (LGL1; GenBank accession no. AF109674) encoding a deduced polypeptide of 188 amino acids. Northern analysis confirmed that LGL1 is expressed in human, rat, and mouse fetal lungs, induced by glucocorticoid, developmentally regulated in fibroblasts but not detectable in epithelium. In situ hybridization confirmed LGL1 expression in the mesenchyme, but not in the epithelium, of fetal rat lung, kidney, and gut. The predicted LGL1 gene product (lgl1) showed 81% homology to P25TI, a polypeptide trypsin inhibitor recently identified in human glioblastoma and neuroblastoma cells but not detected in normal human tissues. Both lgl1 and P25TI belong to the CRISP family of cysteine-rich extracellular proteins. Trypsin is produced by both normal bronchial epithelial and lung adenocarcinoma cells. Although additional studies will be necessary to clearly establish a functional role for lgl1, we propose that lgl1 has a role in normal lung development that is likely to be via regulation of extracellular matrix degradation.

Amino Acid Sequence↗
PubMed1997

[Failure of total uncemented trapeziometacarpal prosthesis. A multicenter study].

The total trapeziometacarpal prosthesis that we have designed has been used clinically for five years. We thought it would be useful to revise failures of these prostheses in a multicentre study in order to identify the causes of the problems and to provide necessary modifications for improvement of the results. Eleven surgeons participated in this study, allowing the review of 24 failures out of a total of 188 implanted prosthesis (12.7%). One case of sepsis and three prosthesis dislocations were observed. In ten cases, we found that the cup was not correctly oriented, leading to a progressive loosening of the cup. In five cases, the shaft had sunk into the metacarpal which was associated with modification of the axis of the shaft in relation to the metacarpal in two cases. In three of these cases, the size of the shaft was too small. Twenty-three failures were reoperated. Metallosis of periprosthetic tissues was observed in 6 cases. This disadvantage has disappeared since treating the heads with ionic nitrogen implantation. A larger size of the same type of prosthesis was able to be implanted in 5 cases. A silicone prosthesis was used in 2 cases and a trapezectomy with or without ligamentoplasty was performed in 16 cases. The high failure rate related to a poor orientation of the cup has led us to increase the range of motion of the prosthesis in order to compensate for the possibly poor orientation of the cup during implantation.

Adult↗
PubMed1996

Excision of the trapezium for osteoarthritis of the trapeziometacarpal joint of the thumb.

We assessed the results of 86 trapeziectomies in 83 patients. Simple excision of the trapezium was performed in 54 thumbs. This was combined with shortening of the abductor pollicis longus tendon in 14 thumbs and with soft-tissue interposition and/or ligamentous reconstruction in 17 thumbs. 88% of the patients were satisfied with the result, 76% had relief of pain and 74% had no functional disability. The subjective results achieved with the three different techniques were similar. Clinical assessment of 57 thumbs revealed no statistical difference in web span, thumb adduction-flexion, key pinch and grip strength between the three operative procedures, nor in comparison with the non-operated contralateral hand.

Adult↗
PubMed1996

Glomus tumours of the hand. A retrospective study of 51 cases.

The authors report a series of 51 patients with glomus tumours in the hand. The duration of symptoms before treatment averaged 10 years. No one site or finger was more commonly involved. Objective features were limited to a blue discoloration in 29%, a pulp nodule or a nail deformity in 33%. An osseous defect was seen on plain X-ray films in 36%. Diagnosis depended on clinical suspicion in 90%. Careful dissection and complete excision of the tumour almost always offer permanent relief. A direct transungual approach was used in the subungual tumours with only one cosmetic problem. Recurrence of symptoms occurred in only two cases after a pain-free interval of 2 years.

Adult↗
PubMed1996

Expression and molecular analysis of mutations in prolidase deficiency.

Prolidase (E.C.3.4.13.9) cleaves iminodipeptides. Prolidase deficiency (PD; McKusick 170100) is an autosomal recessive disorder with highly variable penetrance. We have identified two novel alleles in the prolidase gene (PEPD) by direct sequencing of PCR-amplified cDNA from a PD individual asymptomatic at age 11 years: a 551G-->A transition in exon 8 (R184Q) and a 833G-->A transition in exon 12 (G278D). To assess the biochemical phenotypes of these and two previously identified PEPD mutations (G448R and delE452), we have designed a transient-expression system for prolidase in COS-1 cells. The enzyme was expressed as a fusion protein carrying an N-terminal tag, the HA1 epitope of influenza hemagglutinin, allowing its immunological discrimination from the endogenous enzyme with a monoclonal antibody. Expression of the R184Q mutation produced 7.4% of control enzymatic activity whereas the expression of the G278D, G448R, and delE452 mutations produced inactive enzymes. Western analysis of the R184Q, G278D, and G448R prolidases revealed stable immunoreactive material whereas the delE452 prolidase was not detectable. Pulse-chase metabolic labeling of cells followed by immunoprecipitation revealed that the delE452 mutant protein was synthesized but had an increased rate of degradation.

Alleles↗
PubMed1995

[Transmission of forces at the carpal arch in hyperextension of the wrist--mathematical model].

The carpus is a remarkable anatomical structure which combines exceptional mobility and great resistance to stress in all positions. The carpal architecture is the most economical structure in terms of achieving these two functions: mobility and mechanical resistance. The mechanical behavior of the carpus can be studied through a vectorial and analytical analysis of the transmission of loads. This analysis permits determination of the repartition of strains at the level of the carpal arch and the role of important structures such as the transverse carpal ligament. By this analysis it is also possible to anticipate the result of certain surgical procedures such as the wedge osteotomy for Kienböck disease.

Biomechanical Phenomena↗
PubMed1995

[Percutaneous Herbert screw osteosynthesis of the scaphoid bone].

Scaphoid fractures are the most common carpal fractures. Conservative treatment is long, and non-union is frequent after immobilization in a cast. The Herbert procedure is an improvement, but access to the scaphoid is through an extensive open exposure that damages the blood vessels and the anterior radiocarpal ligaments. In order to solve this problem we used the Herbert screw for percutaneous internal fixation resulting in minimal operative trauma. This procedure requires intraoperative x ray guidance and the use of the accessories of the Herbert set except the "Jick". We operated 23 patients for acute fracture (19 cases) or nonunion (4 cases) of the waist of the scaphoid. In this study, the average follow-up was 16 months and the average age was 32 years. There were 18 men and 5 women. In 18 cases the fracture occurred on the right side. The average immobilization was 15.5 days. Union was obtained in all patients. Postoperative range of motion was 95% of the unaffected side. Key pinch was 6% better than on the unaffected side (the dominant hand was affected in 81% cases). Patients returned to work after an average of 7 weeks.

Adolescent↗
PubMed1994

Four novel PEPD alleles causing prolidase deficiency.

Mutations at the PEPD locus cause prolidase deficiency (McKusick 170100), a rare autosomal recessive disorder characterized by iminodipeptiduria, skin ulcers, mental retardation, and recurrent infections. Four PEPD mutations from five severely affected individuals were characterized by analysis of reverse-transcribed, PCR-amplified (RT-PCR) cDNA. We used SSCP analysis on four overlapping cDNA fragments covering the entire coding region of the PEPD gene and detected abnormal SSCP bands for the fragment spanning all or part of exons 13-15 in three of the probands. Direct sequencing of the mutant cDNAs showed a G-->A, 1342 substitution (G448R) in two patients and a 3-bp deletion (delta E452 or delta E453) in another. In the other two probands the amplified products were of reduced size. Direct sequencing of these mutant cDNAs revealed a deletion of exon 5 in one patient and of exon 7 in the other. Intronic sequences flanking exons 5 and 7 were identified using inverse PCR followed by direct sequencing. Conventional PCR and direct sequencing then established the intron-exon borders of the mutant genomic DNA revealing two splice acceptor mutations: a G-->C substitution at position -1 of intron 4 and an A-->G substitution at position -2 of intron 6. Our results indicate that the severe form of prolidase deficiency is caused by multiple PEPD alleles. In this report we attempt to begin the process of describing these alleles and cataloging their phenotypic expression.

Alleles↗
PubMed1984

[Use of pectoralis major myocutaneous flaps in cervicofacial surgery. Our experience with 46 cases].

Musculocutaneous flaps from pectoralis major were used during cervico-facial surgery for repair after cancer operations in 46 patients. Use of this technique in surgical practice is discussed as a function of the site of cancer, and results described in relation to the viability of the flap and the outcome. Removal of the flap is simple and possible by a one-stage operation, and the method provides functional improvement for these patients.

Adult↗
PubMed1981

[Salivary gland cylindromas. Retrospective study of 65 cases (author's transl)].

A retrospective study of prognostic, clinical, and histological features in 65 cases of salivary gland cylindromas treated in the Hôpital Salpêtrière, Paris, was conducted. Vital prognosis was related to the initial size of the tumour, the presence of pain, and evidence of cellular anomalies or invasion of neighbouring structures on histological examination. Metastatic spread is related to peritumoural extension, and local recurrence has a prognostic value because of its relationship to later metastatic involvement.

Adult↗