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Biomedical subjects

R Lagier

Publications and source records attributed to R Lagier.

At least 19 recordsLinked to original sources
PubMed2005

Bone eburnation in rheumatic diseases: a guiding trace in today's radiological diagnosis and in paleopathology.

Bone eburnation is a common anatomical trace of chronic arthropathy. However, its topographical analysis in rheumatic diseases can contribute to knowledge about the latter, by explaining today's diagnosis through radiology as well as by giving an historical perspective through paleopathology. After recalling that eburnated areas can also originate in infectious arthritis, the present analysis consists in a comparison between macroscopic and radiological observations of both osteoarthritis (OA) and rheumatoid arthritis (RA) at an advanced stage. It focuses on the human femoral head because of its demonstrative interest. Two main observations emerge from our study. The eburnated surface is less extensive in OA (where it appears to be essentially linked to the original structure of the hip) and more extensive in RA at an advanced stage (where an additional systemic factor is predominant). The size of the associated osteophytes appears to be inversely proportional to the extent of the corresponding eburnated area. In connection with the OA-RA comparison above, the contribution of the original joint structure to bone eburnation was also illustrated by acromiohumeral eburnation in shoulder OA and by the comparison with dog hip OA. It must also be noted that a femoral head bone remodeling similar on the whole to that of OA can occur in ochronotic arthropathies whose causal chondropathy is due to a genetic defect. Originating in an identified chondropathy, eburnation in ochronotic arthropathy gives us the opportunity to study an OA-type bone remodeling per se as in an experiment supplied by nature and involving a human hip. However, since RA and ochronotic arthropathy are due to a diffuse chondropathy, both may create a similar macroscopic (and thus radiological) eburnation topography.

Aged↗
PubMed2003

Magnesium whitlockite, a calcium phosphate crystal of special interest in pathology.

Whitlockite (in fact magnesium whitlockite) is a calcium orthophosphate crystal in which, in biological conditions, magnesium is partly substituted for calcium. Identified in X-ray or electron diffraction patterns, it occurs in physiological or pathological conditions at extra or intratissular sites, mainly in tissues of non-epithelial origin. In a range of pathological calcifications investigated by X-ray diffraction, we noted that whitlockite appeared to be frequently associated with apatite, particularly in "dystrophic calcifications" of tuberculous origin. These personal observations could be correlated with documented data in oral pathology (dental calculus, salivary stones, and dental caries). Whitlockite deposits have also been reported in non-infectious conditions, such as in aortic media, cartilage, and bone tissue. Whereas the formation of both apatite and magnesium whitlockite appears to be caused by the binding of their constituting ions with proteolipids, magnesium inhibits apatite originating from amorphous calcium phosphate to the benefit of whitlockite formation. Possibly, the development of magnesium whitlockite may provide an interesting marker for magnesium metabolism. Further studies linking histology to crystallography might relate the crystal to issues, such as tuberculous calcifications or diseases of bone tissue, and might be useful for potential diagnostic orientation.

Calcinosis↗
PubMed2001

Nosology versus pathology, two approaches to rheumatic diseases illustrated by Alfred Baring Garrod and Jean-Martin Charcot.

OBJECTIVES: To show why and how, without underestimating the popular perception of the word 'rheumatism', a medical approach to rheumatic diseases needs to consider the distinction between nosology (the study of diseases) and pathology [anatomopathology (the study of lesions) and physiopathology (the study of functional disturbances)]. METHODS: Selected quotations reflecting the thought processes of two famous physicians whose clinical activity (orientated towards nosology) was firmly based on pathology (mainly physiopathology in the case of A. B. Garrod and mainly anatomopathology in the case of J.-M. Charcot) are discussed. RESULTS: Starting from the physiopathological criterion of hyperuricaemia in gout, Garrod's thought processes led him to name and study rheumatoid arthritis. Alongside his neurological work, Charcot's thought processes led him to underline the common anatomical changes which could be observed in some nosologically distinct forms of chronic rheumatism. CONCLUSIONS: Selected older texts of both authors provide good examples of a methodology which can still be useful for present-day rheumatologists, particularly during their training period. They could serve as a guide to clarify some semantic ambiguities concerning nosology and pathology and for a better understanding of some clinical and radiological overlaps between distinct nosological entities.

England↗
PubMed1997

Synovial cyst and degeneration of the transverse ligament: an unusual cause of high cervical myelopathy. Case report.

A case of cystic degeneration of the transverse ligament located posteriorly to the dens and causing compression to the lower medulla and upper cervical spinal cord is reported. The clinical, pathological, and radiological findings are described and compared to the literature to characterize this syndrome more fully. The advantages of a posterolateral surgical approach are stressed.

Aged↗
PubMed1997

The enduring mark left by Jean-Martin Charcot on rheumatology.

Although Charcot is remembered above all as an outstanding neurologist, he also left a lasting imprint on the study of rheumatic diseases, primarily in two fields. a) He performed a pathologic-nosographic confrontation based on principles that remain relevant in today's era of imaging techniques. His vision as a pathologist allowed him to establish links between nonspecific lesions, which led him to develop a unified concept of chronic rheumatism. At the same time however, his experience as a clinician gave him a sense of the nosologic distinctions that are widely accepted today. b) He analyzed osteoarticular dystrophies associated with neurologic disorders, most notably tabetic arthropathies with epiphyseal fragmentation and in some instances spontaneous fractures. In addition, a constellation of alterations of the synovial membrane, ligaments, and muscles identified in those analyses foreshadowed today's concept of reflex sympathetic dystrophy syndrome.

Arthropathy, Neurogenic↗
PubMed1996

Effect of human immunodeficiency virus infection on hepatitis C virus infection in hemophiliacs.

Chronic liver disease due to hepatitis C virus (HCV) infection is a major problem in hemophiliacs. Recent reports suggested that hemophiliacs coinfected with hepatitis C virus and human immunodeficiency virus (HIV) have an increased incidence of liver failure but the mechanism of accelerated liver injury is not clear. We tested plasma from 100 hemophiliacs for anti-HCV by second generation ELISA, anti-HIV by EIA, and HCV RNA and HIV RNA by branched DNA and polymerase chain reaction assays to determine if hemophiliacs coinfected with HCV and HIV have higher HCV RNA levels and more active liver disease. Seventy-nine (79%) patients were anti-HCV positive, of whom 85% were HCV RNA positive. None of the anti-HCV-negative patients had detectable HCV RNA in plasma. Forty-two (42%) patients were anti-HIV positive, of whom 47% had detectable HIV RNA. All the anti-HIV-positive patients were also anti-HCV positive. The prevalence of both anti-HCV and anti-HIV increased significantly with age. There was no difference in HCV RNA levels between anti-HIV-positive and anti-HIV-negative patients (mean: 21 +/- 4 vs 18 +/- 5 Meq/ml), although HCV RNA levels were significantly higher in anti-HIV-positive patients with CD4 counts < 200/mm3 (P = 0.008). There was an inverse correlation between HCV RNA levels and CD4 counts but no correlation was found between HCV RNA and serum aminotransferase levels. We found a high prevalence of HCV and HIV coinfection in our hemophiliacs. Hepatitis C virus replication appears to be increased in patients with severe immunodeficiency secondary to progressive HIV infection. However, there was no correlation between HCV RNA and serum ALT level, suggesting that HCV is not directly cytopathic.

Adolescent↗
PubMed1996

Pathological anatomy in the teaching of rheumatology.

Whereas rheumatology regroups nosological entities, its teaching must be partly based on a presentation of the corresponding anatomopathological aspects which in fact are various patchworks made up of elementary, generally nonspecific lesions of osteoarticular pathology. Such an approach will provide an objective guideline between the needs of the practitioner (who often thinks in terms of morphology through radiological images) and the plethora of modern basic data. Thus the methods can be adapted to the needs of various audiences (medical students, specialists in training, paramedical personnel) and to every material and financial possibilities. In all cases it must be integrated with clinical and radiological lectures, based on macroscopic and radiological correlations and complemented, as far as possible, with appropriate histological images.

Education, Medical↗
PubMed1996

Accurate quantification of hepatitis C virus (HCV) RNA from all HCV genotypes by using branched-DNA technology.

In studies monitoring disease progression and therapeutic response, it is essential that the method used for hepatitis C virus (HCV) quantification not be influenced by genotypic variability. The branched DNA assay provides a reliable method for the quantification of HCV RNA. A modified set of oligonucleotide probes for the branched DNA assay was developed to enhance the efficiency of binding to genotypic variants of HCV. The improved branched DNA assay (HCV RNA 2.0) yielded highly reproducible quantification of hepatitis C virus RNA and displayed a nearly 600-fold dynamic range in quantification up to 120 Meq of HCV RNA per ml. The quantification limit was set at 0.2 Meg of HCV RNA per ml to ensure a specificity of > or = 95%. With this lowered quantification limit and the enhanced hybridization of the probes, the HCV RNA 2.0 assay exhibited a high level of sensitivity (96%) and was virtually unaffected by the genotypic variability of HCV. The HCV RNA 2.0 assay may be a useful tool for following HCV RNA levels throughout the course of disease, selecting patients for therapy, and evaluating therapeutic response.

Base Sequence↗
PubMed1995

Rheumatism as perceived by some quotations: as seen by the patient and physician.

The word "rheumatism", introduced in ancient times, is still used directly or indirectly, in parallel with the terms of the modern nosography. The reasons for this persistence can be sought in the history of the concept, which can be approached via quotations from texts written either by authors who describe popular beliefs or their own sufferings; or by physicians known to have played a prominent role in the individualization of rheumatology. The word "rheumatism" was first used mainly to designate a painful fluxion of the tissues located between the skin and the internal organs. It gradually lost ground to more descriptive terms suggestive of joints. Thus, the concept of "rheumatism" still bears the hallmark of its "popular" roots and is on a level parallel to but distinct from that of modern nosography. Awareness of its origins may improve communication between physicians and patients and also raises questions about the foundations of the concept of "rheumatic disease".

Attitude of Health Personnel↗
PubMed1990

Case report 591: Osteoarthrosis (OA) of hip associated with microscopic gouty tophi.

It has been demonstrated in this 58-year old woman that osteoarthrosis OA coexisted in a hip with microscopic gouty tophi. It is demonstrated that the bone erosions around the hip in this case were due to OA and not gouty arthritis. It is believed that OA is not a consequence of gout and that such an association between gout and OA is exceptional. It is maintained that a true association exists between OA and ochronosis while a relationship may exist between OA and chondrocalcinosis, but the nature of this relationship is not clear.

Female↗
PubMed1990

A case of hip osteoarthrosis contaminated by fungi. A histological study.

A pathological study of a surgical specimen of hip osteoarthrosis presenting a superficial fungal infection (presumably Aspergillus) without any known origin is reported. Fungal penetration was mild in cartilage and fibrocartilage and more pronounced in naked cancellous bone, but it did not occur in eburnated bone or in the deep osteomedullar area. This observation indicates an unusual combination of infection and osteoarthrosis. Relationships between fungi and bone or cartilage as well as interaction between osteoarthrotic remodeling and a superimposed disease are discussed.

Humans↗