In Vivo Assessment of Skin Surface Pattern: Exploring Its Potential as an Indicator of Bone Biomechanical Properties.

The mechanical properties of bone tissue are the result of a complex process involving collagen-crystal interactions. The mineral density of the bone tissue is correlated with bone strength, whereas the characteristics of collagen are often associated with the ductility and toughness of the bone. From a clinical perspective, bone mineral density alone does not satisfactorily explain skeletal fragility.

Quantification of Microstructural Changes in the Dermis of Elderly Women Using Morphometric Indices of the Skin Surface.

Objective: The main objective of this study was the development of a non-invasive mathematical marker of the skin surface, the characteristic length, to predict the microstructure of the dermis. This marker, at the individual level, is intended to provide the biological age of the patient in the context of personalised medicine for the elderly.

Study Design: To validate this hypothesis, a clinical study was conducted on 22 women over 60 years old from a population of osteoporotic subjects who sustained a femoral neck fracture: a morphological analysis of the skin surface was performed on the patient's forearm and quantitatively compared with microarchitectural parameters of the dermis.

Early impairment of cartilage poroelastic properties in an animal model of ACL tear.

Background: In more than 50% of cases, anterior cruciate ligament (ACL) lesions lead to post-traumatic osteoarthritis. Ligament reconstruction stabilizes the joint, but the tear seems to impair the poroelasticity of the cartilage: synovial membrane fluid inflammation is observed 3 weeks after tearing. There have been some descriptions of visible cartilage changes, but poroelasticity has never been analyzed at this early stage.

Human dentin characteristics of patients with osteogenesis imperfecta: insights into collagen-based biomaterials.

Osteogenesis imperfecta (OI), also known as "brittle bone disease", is a rare genetic disorder of the skeleton, whose most benign form I corresponds to autosomal dominant mutations in the genes encoding type I collagen (COLA1, COLA2). Several associated skeletal manifestations are often observed but, surprisingly, while dentin defects often reflect genetic bone disorders, about half of OI patients have no obvious oral manifestations. Here, we investigated the collagen, mineral and mechanical properties of dentin from deciduous teeth collected from patients with mild form of OI and displaying no obvious clinical signs of dentinogenesis imperfecta.

Correlation between skin and bone parameters in women with postmenopausal osteoporosis: A systematic review.

Skin and bone share similarities in terms of biochemical composition.Some authors have hypothesized that their properties could evolve concomitantly with age, allowing the estimation of the parameters of one from those of the other.We performed a systematic review of studies reporting the correlation between skin and bone parameters in women with postmenopausal osteoporosis.

Mechanical alterations of the bone-cartilage unit in a rabbit model of early osteoarthrosis.

Objective: The purpose of this study was to assess mechanical properties along with microstructural modifications of the hyaline cartilage (HC), calcified cartilage (CC) and cortical plate (Ct.Pt), in an anterior cruciate ligament transection (ACLT) model. Medial femoral condyles of six healthy rabbits (control group) and of six ACLT rabbits 6 weeks after OA induction were explanted.

Chronic alcohol abuse in men alters bone mechanical properties by affecting both tissue mechanical properties and microarchitectural parameters.

Objective Of The Study: Alcohol-induced secondary osteoporosis in men has been characterized by higher fracture prevalence and a modification of bone microarchitecture. Chronic alcohol consumption impairs bone cell activity and results in an increased fragility. A few studies highlighted effects of heavy alcohol consumption on some microarchitectural parameters of trabecular bone.

Microscale mechanical and mineral heterogeneity of human cortical bone governs osteoclast activity.

Human cortical bone permanently remodels itself resulting in a haversian microstructure with heterogeneous mechanical and mineral properties. Remodeling is carried out by a subtle equilibrium between bone formation by osteoblasts and bone degradation by osteoclasts. The mechanisms regulating osteoclast activity were studied using easy access supports whose homogeneous microstructures differ from human bone microstructure.

Contra-lateral hip fracture in the elderly: are decreased body mass index and skin thickness predictive factors?

Purpose: A correlation between soft tissue thickness and osteoporosis has been suggested. We aimed to estimate if a low body mass index (BMI) and/or a decrease of skin thickness could estimate the risk of contra-lateral hip fracture.

Methods: First, we performed a retrospective analysis of 1268 patients treated for a hip fracture.

DNA amplification of HIV-1 in seropositive individuals and in seronegative at-risk individuals.

We assessed the HIV-1 status of seropositive and seronegative at-risk individuals by the polymerase chain reaction. Fifty-four out of 55 HIV-1-seropositive samples scored positive. However, HIV-1 proviral DNA was not detected in 16 seronegative homosexuals, 20 seronegative polytransfused haemophiliacs and 20 seronegative thalassaemic children, 20 individuals with isolated and persistent anti-core antibodies and 74 seronegative blood donors.

Anticardiolipin antibodies in HIV-negative and HIV-positive haemophiliacs.

Anticardiolipin antibodies (ACA) were determined in 72 heavily transfused haemophiliacs, 43 HIV-positive and 29 HIV-negative. The presence of ACA was detected in 10 patients, all of them infected by HIV: 8 in CDC II, 1 in CDC III and 1 in CDC IV. The comparison with alterations of other laboratory markers in HIV-infected patients did not show any statistically significant difference between ACA-negative and -positive patients.

Clinical and biological survey of haemophilia A and B patients infused with French heat-treated concentrates.

The efficiency of heat treatment procedures of factor VIII and factor IX concentrates, prepared from voluntary, non-paid donors by three French Blood Transfusion Centres, on the inactivation of HIV and non-A, non-B hepatitis (NANB) viruses was assessed. Some 43 patients (26 haemophilia A, 17 haemophilia B) were followed for at least 1 year by testing for HIV antibodies and alanine aminotransferase (ALT). No HIV seroconversion was observed indicating that heat treatment was completely efficient.

Long-term evaluation of HIV antigen and antibodies to p24 and gp41 in patients with hemophilia. Potential clinical importance.

To investigate the relation between human immunodeficiency virus (HIV) antigenemia and clinical manifestations of HIV infections, we studied 96 patients with hemophilia who were positive for HIV antibody, for a median of 34 months. Every 4 to 10 months a clinical and laboratory examination was performed and serum samples were tested for three HIV markers: HIV antigen, antibody to p24, and antibody to gp41. Twenty-two subjects (23 percent) were found to be positive for HIV antigen: 8 were positive upon entry and remained so (Group 1), and 14 became positive during the study, 4 to 26 months after HIV antibody appeared (seroconversion), 13 of whom remained positive for HIV antigen (Group 2).

The role of HIV infectivity and composition of factor VIII concentrates on the immunity of haemophiliacs positive for HIV antibodies.

Forty-six subjects (44 HIV antibody-positive) with some degree of immune deficiency (at least TH/TS ratio below 1) were randomly distributed into 4 treatment groups. Each group was assigned to 1 of 4 products to be used exclusively for a 1-year period: 1 concentrate was of intermediate purity and not heat-treated, and 3 were heat-treated in order to inactivate HIV, 2 of them being of higher purity. At 4-6-month intervals, check-ups, including as markers clinical examination, platelet, lymphocyte and T cell subset counts, IgG levels and delayed hypersensitivity test, were carried out.

Hemophilic patients with an inhibitor to factor VIII treated with high dose factor VIII concentrate. Results of a collaborative study for the evaluation of factor VIII inhibitor titer, recovery and half life of infused factor VIII.

The long term treatment of hemophilic patients with an inhibitor to Factor VIII has been difficult although some success with immunosuppressive agents has been reported. Eighteen hemophilic patients, mainly from Bonn in Germany, but also from other countries, have completed a high dose Factor VIII treatment in an attempt to reduce their inhibitor titer and induce "immune tolerance" to Factor VIII. Plasma samples from the 18 patients collected before and after infusion of 50 units Factor VIII/kg body weight were sent to five laboratories to evaluate inhibitor titer, Factor VIII recovery and half life.

[Immunological study of a hemophiliac treated according to the Bonn protocol for 2 1/2 years].

A major haemophiliac A, 27 years old, has been treated during 30 months, with high dosage of imported Factor VIII, in order to reduce the titer of a F VIII antibody. A good clinical result has been obtained. No sign of immunodeficiency has been observed.

HLA antigens and factor VIII antibody in classic hemophilia. European study group of factor VIII antibody.

Possible interrelations between the immune response factor VIII and the major histocompatibility system were investigated in 57 multi-transfused hemophilic brothers belonging to 26 families. Linkage appears very unlikely although formal proof of independence cannot be offered. The HLA system, therefore, does not provide markers predictive for the development of antibodies to factor VIII in severe hemophilia A.