Early effects of the antineoplastic agent salinomycin on mitochondrial function.

Salinomycin, isolated from Streptomyces albus, displays antimicrobial activity. Recently, a large-scale screening approach identified salinomycin and nigericin as selective apoptosis inducers of cancer stem cells. Growing evidence suggests that salinomycin is able to kill different types of non-stem tumor cells that usually display resistance to common therapeutic approaches, but the mechanism of action of this molecule is still poorly understood. Since salinomycin has been suggested to act as a K(+) ionophore, we explored its impact on mitochondrial bioenergetic performance at an early time point following drug application. In contrast to the K(+) ionophore valinomycin, salinomycin induced a rapid hyperpolarization. In addition, mitochondrial matrix acidification and a significant decrease of respiration were observed in intact mouse embryonic fibroblasts (MEFs) and in cancer stem cell-like HMLE cells within tens of minutes, while increased production of reactive oxygen species was not detected. By comparing the chemical structures and cellular effects of this drug with those of valinomycin (K(+) ionophore) and nigericin (K(+)/H(+) exchanger), we conclude that salinomycin mediates K(+)/H(+) exchange across the inner mitochondrial membrane. Compatible with its direct modulation of mitochondrial function, salinomycin was able to induce cell death also in Bax/Bak-less double-knockout MEF cells. Since at the concentration range used in most studies (around 10 µM) salinomycin exerts its effect at the level of mitochondria and alters bioenergetic performance, the specificity of its action on pathologic B cells isolated from patients with chronic lymphocytic leukemia (CLL) versus B cells from healthy subjects was investigated. Mesenchymal stromal cells (MSCs), proposed to mimic the tumor environment, attenuated the apoptotic effect of salinomycin on B-CLL cells. Apoptosis occurred to a significant extent in healthy B cells as well as in MSCs and human primary fibroblasts. The results indicate that salinomycin, when used above µM concentrations, exerts direct, mitochondrial effects, thus compromising cell survival.

Management of subacute acetabular osteomyelitis in a child.

Clinical manifestations of subacute osteomyelitis may lead to delayed diagnosis. Acetabular subacute osteomyelitis is an uncommon disease. Bone tumors are usually suggested first. Diagnosis is often made based on radiological findings. We report on the case of a 9-year-old girl who consulted at the emergency department because of limping and pain in her left limb lasting 2 weeks. No fever was reported. Physical examination found a clear, painful reduction in hip mobility. X-ray findings revealed a posterior loss of bone in the acetabular wall. MRI found a mild invasion of the periarticular hip joint and muscles. The surgical exploration of the hip found a collection in the posterior acetabular wall suggesting septic disease. Bacteriological and pathological exams confirmed acetabular subacute osteomyelitis. Nine months after surgery, antibiotic therapy, and physiotherapy, the patient was painless and the hip mobility showed near normal values with a reduction in external rotation and flexion. The aim of this case report is to review the characteristics of subacute acetabular osteomyelitis, including therapeutic modalities, underlining surgical debridement as a rule for both diagnosis and treatment.

[BCG multifocal osteomyelitis. A case report]. / Ostéomyélite multifocale à BCG : à propos d'un cas.

Multifocal osteomyelitis is a rare complication of the Bacille Calmette-Guerin (BCG) vaccine. It particularly affects immunocompromised children and poses a difficult diagnostic problem. A 6-month-old boy had BCG vaccination postnatally and developed extensive disseminated skeletal osteomyelitis. He was found to have severe combined immunodeficiency. Despite antibiotic therapy and bone marrow grafting, the disease was fatal.

Wnt signaling is involved in human articular chondrocyte de-differentiation in vitro.

Osteoarthritis is the most prevalent form of arthritis in the world. Certain signaling pathways, such as the wnt pathway, are involved in cartilage pathology. Osteoarthritic chondrocytes undergo morphological and biochemical changes that lead to chondrocyte de-differentiation. We investigated whether the Wnt pathway is involved in de-differentiation of human articular chondrocytes in vitro. Human articular chondrocytes were cultured for four passages in the presence or absence of IL-1 in monolayer or micromass culture. Changes in cell morphology were monitored by light microscopy. Protein and gene expression of chondrocyte markers and Wnt pathway components were determined by Western blotting and qPCR after culture. After culturing for four passages, chondrocytes exhibited a fibroblast-like morphology. Collagen type II and aggrecan protein and gene expression decreased, while collagen type I, matrix metalloproteinase 13, and nitric oxide synthase expressions increased. Wnt molecule expression profiles changed; Wnt5a protein expression, the Wnt target gene, c-jun, and in Wnt pathway regulator, sFRP4 increased. Treatment with IL-1 caused chondrocyte morphology to become more filament-like. This change in morphology was accompanied by extinction of col II expression and increased col I, MMP13 and eNOS expression. Changes in expression of the Wnt pathway components also were observed. Wnt7a decreased significantly, while Wnt5a, LRP5, ß-catenin and c-jun expressions increased. Culture of human articular chondrocytes with or without IL-1 not only induced chondrocyte de-differentiation, but also changed the expression profiles of Wnt components, which suggests that the Wnt pathway is involved in chondrocyte de-differentiation in vitro.

The roles of canonical and non-canonical Wnt signaling in human de-differentiated articular chondrocytes.

Osteoarthritis is the most prevalent form of arthritis in the world and it is becoming a major public health problem. Osteoarthritic chondrocytes undergo morphological and biochemical changes that lead to de-differentiation. The involvement of signaling pathways, such as the Wnt pathway, during cartilage pathology has been reported. Wnt signaling regulates critical biological processes. Wnt signals are transduced through at least three intracellular signaling pathways including the canonical Wnt/ß-catenin pathway, the Wnt/Ca2 + pathway and the Wnt/planar cell polarity pathway. We investigated the involvement of the Wnt canonical and non-canonical pathways in human articular chondrocyte de-differentiation in vitro. Human articular chondrocytes were cultured through four passages with no treatment, or with sFRP3 treatment, an inhibitor of Wnt pathways, or with DKK1 treatment, an inhibitor of the canonical pathway. Chondrocyte-secreted markers and Wnt pathway components were analyzed using western blotting and qPCR. Inhibition of the Wnt pathway showed that the canonical Wnt signaling probably is responsible for inhibition of collagen II expression, activation of metalloproteinase 13 expression and regulation of Wnt7a and c-jun expression during chondrocyte de-differentiation in vitro. Our results also suggest that expressions of eNOS, Wnt5a and cyclinE1 are regulated by non-canonical Wnt signaling.

Expression patterns of Notch receptors and their ligands in human osteoarthritic and healthy articular cartilage.

Notch pathway plays a pivotal role in cell fate determination. There is much interest surrounding its therapeutic potential, in osteoarthritis, but the expression profile of Notch-related molecules, as well as their relation with cartilage pathological parameters, remains unclear. The purpose of our study is to analyze the expression pattern of Notch family members, type II and type I collagen, in normal (healthy) and osteoarthritic human knee cartilage. Osteoarthritic cartilages were obtained from 3 patients undergoing a total knee replacement. Macroscopically normal cartilage was dissected from 3 human knees at the time of autopsy or surgery. Immunohistochemical staining was performed using Notch1,2,3 and 4, Delta, Jagged, type II collagen and type I collagen antibodies. In healthy cartilage, type II collagen was abundantly expressed while type I was absent. This latter increased proportionally to the osteoarthritic grade. Type II collagen expression remained intense in osteoarthritic cartilage. In healthy cartilage as well as in cartilage with minor lesions, Notch family member's proteins were not or just weakly expressed at the surface and in the cells. However, Notch molecules were over-expressed in osteoarthritic cartilage compared to healthy one. This expression pattern was different according to the cartilage zone and the severity of OA. Our data suggest that Notch signaling is activated in osteoarthritic cartilage, compared to healthy cartilage, with a much more abundant expression in the most damaged areas.

Primary hydatid disease of the thigh. A rare location.

Primary muscle hydatidosis is very rare, accounting for less than 1% of hydatid cyst locations. Clinical symptoms are insidious and non-specific causing a frequent delay in diagnosis. Intramuscular hydatid disease can cause a variety of diagnostic problems, especially in the absence of typical radiologic findings. We report the observation of an 82-year-old man consulting for inguinal tumefaction with radiological exploration suggestive of hydatid cyst of the adductors muscles. Magnetic resonance imaging (MRI) is helpful in diagnosis, since it reveals a very suggestive aspect and demonstrates the relationship between cysts and adjacent structures. Treatment of muscle echinococcosis is based on surgery, which is curative and incurs a low risk of local relapse.

A rare cause of non discal sciatica: schwannoma of the sciatic nerve.

Schwannomas are peripheral nerve sheath tumors. Schwannomas arising in the sciatic nerve are considered a rare condition. Their symptomatology usually mimics sciatic pain due to a herniated disc, which can delay the diagnosis. We report the case of a patient with chronic sciatica in whom Magnetic Resonance Imaging (MRI) examination of the right thigh revealed a tumor of the sciatic nerve. Excision of the tumor was easily performed without neural lesioning. Histopathological examination revealed the tumor to be a schwannoma. No neurologic deficit was noted postoperatively which confirms the good prognosis of this tumor.

Expression of Notch family members in cultured murine articular chondrocytes.

The Notch family is involved in cell differentiation during embryogenesis. Osteoarthritic chondrocytes undergo morphological and biochemical changes leading to the de-differentiation process. In the study reported here, we were interested in the involvement of the Notch pathway in murine articular chondrocyte de-differentiation. Articular chondrocytes were subjected to several cell culture passages and treated with or without a Notch inhibitor, N-[N-(3, 5-difluorophenacetyl-L-alanyl)]-S-phenylglycine t-Butyl Ester (DAPT). Chondrocyte morphology was studied using optical microscopy. Immunocytochemistry and immunoblot were performed to study the expression of collagens and Notch family members. Without DAPT treatment, chondrocyte de-differentiation resulted in fibroblast-like morphology. This was confirmed by immunocytochemical staining and immunoblot analysis, which showed an increase in collagen type I (col I) and a decrease in collagen type II (col II) expression. With DAPT treatment, de-differentiation was delayed. Immunocytochemistry and immunoblot analysis showed during the first passages inhibition of col II expression, which then was re-instituted during the last passage, suggesting chondrocyte re-differentiation. In the study reported here, we showed that inhibition of the Notch receptor not only delayed the de-differentiation process, but also chondrocyte re-differentiation, which confirms the involvement of the Notch pathway in chondrocyte de-differentiation.

CSF phosporylated TAU protein levels correlate with cerebral glucose metabolism assessed with PET in Alzheimer's disease.

One major goal of drug development would be the establishment of biomarkers as objective indicators of normal biological and pathogenetic processes, or pharmacological response to a therapeutic intervention. A potential approach is to investigate proteins in CSF linked to key neuropathological features of Alzheimer's disease (AD). Recently CSF phosphorylated-Tau (p-Tau) levels have been reported to reflect neurofibrillary changes within the brain of patients with AD, however the use of serial CSF investigations in order to monitor the disease progression is not applicable. PET with FDG reveals characteristic patterns in AD patients, however so far no correlation between in vivo metabolic information and pathological features has been reported. In the present study, we tested whether CSF Tau levels correlate with metabolic rate for glucose consumption in a cohort of 28 AD patients. We found a statistically significative correlation between both CSF total and p-TAU protein and relative metabolic indexes obtained from 18FDG-PET scans in parietal, temporal and occipital lobes bilaterally. These results indicate the existence of a correlation between impairment of cerebral metabolism, estimated throughout FDG-PET, and CSF Tau protein levels.

[Osteoid osteoma of the talus and simple bone cyst of the homolateral calcaneus. A rare association]. / Ostéome ostéoïde du talus et kyste osseux essentiel du calcanéus homolatéral. Une association rare.

Osteoid osteoma and simple bone cyst are readily observed in long bones, but are much less common in the short bones of the foot. The association of these two tumors in the same foot is exceptional. We report the case of a 15-year-old girl who presented an osteoid osteoma of the talus and a simple bone cyst of the calcaneus of the left foot. The patient complained of pain in the rear foot for four months which worsened at night and was of the inflammatory type. The physical examination was normal. Standard x-rays revealed a simple bone cyst in the calcaneus which could not explain the nighttime inflammatory pain. Scintigraphy and computed tomography of the left foot revealed an osteoid oseoma of the talus. Biopsy total resection of the osteoid osteoma with curettage and filling with cancellous bone of the simple bone cyst were performed. The patient has been free of recurrence at three years follow-up.

[Rare cause of acute carpal tunnel syndrome: acute metacarpal osteomyelitis]. / Cause rare du syndrome aigu du canal carpien: ostéomyélite aiguë métacarpienne.

Acute carpal tunnel syndrome resulting from acute metacarpal osteomyelitis is an exceptional etiopathogenic entity. A 6-year-old boy developed an acute carpal tunnel syndrome on the left four days after trauma. The carpal tunnel was opened in an emergency setting and exploration revealed a pale median nerve with infiltration of neighboring tissue. After release, pus issued from the depth of the tunnel. A posterior approach disclosed the collection and a total loss of the 4th metacarpal periosteum, leading to the diagnosis of acute osteomyelitis. Edema and pain regressed rapidly with antibiotic therapy. A pathologic fracture of the 4th metacarpal discovered three months later was treated conservatively. At 10 months, the child has a very good functional result despite persistence of a short 4th metacarpal after healing. There was no motor or sensitive neurological deficit and thumb opposition was complete. We have been unable to find any other report of acute metacarpal osteomyelitis leading to acute carpal tunnel syndrome. Emergency treatment is crucial. Opening the annular ligament is the only way to achieve complete nerve recovery.

[Brachyolmia at autosomal recessive transmission]. / Brachyolmie à transmission autosomique récessive.

BACKGROUND: Brachyolmia is a form of spondylodysplasia; sufferers have a short stature limited to the trunk that is recessively inherited. There may be other minor abnormalities in some cases. CASE REPORTs. Four brothers, born to consanguineous normal parents, developed short stature and scoliosis that were only identified after the age of 5 years (from 8 to 14 years). The three oldest patients had facial anomalies with flattened mid-face and enlarged lips. X-rays showed scoliosis, universal platyspondyly, irregular iliac crests and short, enlarged femoral necks. CONCLUSION: Evidence of abnormalities in other areas than the spine confirms the heterogeneity for the disease.

[Osteogenesis imperfecta with hypertrophic callus. Apropos of 2 cases with early onset]. / Ostéogenèse imparfaite avec cal hypertrophique. A propos de deux observations à début précoce.

BACKGROUND: The callus that forms at the site of recent fractures in patients with osteogenesis imperfecta is usually normal, but hyperplastic callus may develop. CASE REPORTS: Case 1. A hyperplastic callus with local inflammation developed at the site of a fracture of the left thigh of a boy, aged 11 months suffering from osteogenesis imperfecta. This disease was characterized by the progressive development of broad limbs, bone islands on skull x-rays and blue sclerae. He had also had fractures at the ages of 4 and 7 months. Follow-up showed that this boy, now aged 15 years, had several fractures with the development of similar hyperplastic calluses. These limitated joint motility, causing him to remain confined to his bed. Case 2. This girl of consanguineous parents had a fracture of the femora at the age of 1 month; she had blue sclerae and developed a hyperplastic callus. The roentgenographic studies showed generalized osteopenia and deformities indicating osteogenesis imperfecta. CONCLUSION: Hyperplastic callus may develop in osteogenesis imperfecta. Its diagnosis may be difficult with neoplasms of bone, such as osteosarcoma, and its treatment is difficult.

[Antibiotic-loaded orthopedic cements. Pharmacokinetics and bone level]. / Ciments orthopédiques aux antibiotiques. Pharmacocinétique et taux osseux.

A mechanical study in the laboratory of 10 types of cement has shown that the characteristics of low viscosity antibiotic-loaded cements are comparable with those of standard cement without antibiotic and of standard viscosity. A study of the release of Gentamycin in 26 patients treated by total hip replacement showed that the concentration of antibiotic in the drainage fluid was much greater than the minimum inhibitory concentration whereas the low blood concentration gave no risk of ototoxicity or nephrotoxicity. This method of administration achieved antibiotic concentrations in the tissues in contact with the prosthesis 10 times greater than those obtained by injection. In sheep, the intra-osseous concentration was studied in 32 femora after insertion of low viscosity Gentamycin-loaded cement. The levels remained raised to 4 times the minimum inhibitory concentration for up to one year after operation, even with cements with a low concentration of antibiotic of 0.6 g/dose. The concentrations obtained in the drainage fluid, in the peri-prosthetic tissues and especially in bone, confirm the effectiveness and the prolonged action of antibiotic therapy by cement and its value in the revision of infected prostheses and in prophylaxis in primary surgery. This justifies the further study of combinations of cement with new antibiotics with a broader spectrum than Gentamycin since there is no concern with the cements currently in use that the mechanical quality is less than that of standard cement.

[Weight-bearing early after osteosynthesis of the femoral neck by nail-plate (100 cases)]. / Appui précoce après ostéosynthèse du col fémoral par vis plaque (100 cas).

One hundred trochanteric or transcervical fractures, 64 of which were in patients more than 75 years old, were treated by internal fixation with a THS nail-plate. This device is characterised by a better bending strength than a one-piece nail-plate and a design which limits the risk of displacement of the screw in the head so that immediate weight-bearing can be allowed. Weight was borne on the limb in 81 cases at the tenth post-operative day. It did not improve the mortality, there being 17 deaths by the third month but it greatly helped post-operative care and rehabilitation without producing any additional complications. As a result, 43 per cent of patients could return home by the 45th post-operative day and 74 per cent had recovered their previous level of autonomy within three months of operation. There were only four mechanical complications, all in transcervical fractures: one crack fracture in the femoral head and three displacements following inadequate reduction, treated by prosthetic replacement. The follow-up of 80 patients at three months showed that consolidation always developed between the 45th and 90th day with full weight-bearing and a stable radiological picture. There was no intra-articular penetration or bending of the screw and no break-out of the implant. Whilst it is a definite advance in the treatment of trochanteric fractures, a longer follow-up is needed to determine its place compared with prostheses in transcervical fractures.