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Biomedical subjects

Michel Laroche

Publications and source records attributed to Michel Laroche.

17 recordsLinked to original sources

Remitting seronegative symmetrical synovitis pitting oedema after BCG instillation.

Remitting seronegative symmetrical synovitis pitting oedema (RS3PE) is a distinct form of seronegative rheumatoid arthritis like polyarthritis. It is characterized by late onset symmetrical joint involvement and pitting oedema of hands and feet (JAMA 254(19):2763-2767, [1]). Polyarthritis secondary to intravesical Bacillus Calmette Guerin (BCG) therapy has been reported (Clin Rheumatol 21:536-537, [2]). To our knowledge, about 0.5% of patients receiving BCG instillation presented polyarthritis, but only one case of RS3PE has been reported (J Rheumatol 28:1699-1701, [3]). We described the second case of RS3PE following intravesical BCG instillation of bladder carcinoma.

Adjuvants, Immunologic↗

Systemic vasculitis revealing a benign tumor: a paraneoplastic syndrome?

Systemic vasculitis is a rare event in the course of malignant tumors and has not been described in association with benign tumors. We report a case of renal oncocytoma in a patient who presented with digital necrosis, arthralgia, myalgia, and a decline in general health. The symptoms resolved fully after tumor excision, supporting a diagnosis of paraneoplastic syndrome.

Adenoma, Oxyphilic↗

[Epidural abscess after prostatic biopsies].

Prostatic biopsy is a routine clinical procedure often wrongly considered to be perfectly harmless. The authors report the first case of epidural abscess after prostatic biopsy, despite properly conducted antibiotic prophylaxis. Although the epidural space is a known site of infection, the relationship with prostatic biopsies has never been previously reported. This clinical case emphasizes the need for complete patient information and the importance of anti-infective prophylaxis guidelines.

Biopsy↗

Phosphate diabetes, tubular phosphate reabsorption and phosphatonins.

Phosphate diabetes is defined as inadequate tubular reabsorption. Hypophosphatemia is responsible for most of the clinical manifestations, which vary with the age of the patient and the severity of the phosphate wasting. Vitamin D-resistant rickets in children or osteomalacia in adults, osteoporosis, bone pain including spinal pain, and pain in the joints and periarticular areas are the main manifestations. Several factors are known to affect tubular phosphate reabsorption via the sodium/phosphate cotransporters located on the tubular cell membranes. Factors that decrease phosphate reabsorption include a high intake of dietary phosphate, acidosis, parathyroid hormone (PTH), PTH-related peptide (PTHrp), glucocorticoid therapy, calcitonin, and vitamin D. On the other hand, a low-phosphate diet, alkalosis, growth hormone, insulin, IGF-1, and thyroid hormones increase tubular phosphate reabsorption. Physiological concepts about tubular phosphate reabsorption have been radically changed by the recent identification of phosphaturic factors called phosphatonins. The most extensively studied phosphatonin to date is fibroblast growth factor 23 (FGF23), which was first identified in patients with tumor-induced osteomalacia and shown to be secreted by the neoplastic cells. The FGF23 has also been implicated in autosomal dominant hypophosphatemic rickets, in which a gene mutation results in production of abnormal FGF23 that resists hydrolysis. In healthy individuals, FGF23 contributes to regulate phosphate reabsorption via Na/Pi cotransporters. Other phosphatonins may exist, such as matrix extracellular phosphoglycoprotein (MEPE) and secreted frizzled-related protein 4 (SFRP4), whose role remains to be defined. The part played by these proteins in idiopathic renal phosphate wasting in adults needs to be investigated.

Extracellular Matrix Proteins↗

Prevalence and antimicrobial resistance of Campylobacter coli isolated from fattening pigs in France.

Campylobacter are a leading cause of human diarrhea. The usual source of infection is contaminated food, particularly poultry but pork has also been described. The veterinary use of antimicrobial drugs has been suggested to be largely responsible for resistance in human isolates of this zoonotic pathogen. A study was carried out to investigate the occurrence and antimicrobial resistance of Campylobacter isolated from French fattening pigs. From March 1998 to June 1999, stomach samples were collected at slaughter from 240 fattening pigs originating from 24 different farms. Half of the pigs were found to be positive for Campylobacter but considerable variation was observed between farms. Isolates all belong to the Campylobacter coli species. Susceptibilities of the strains were determined for five antimicrobial drugs using agar dilution. Resistance to tetracycline and erythromycin was high (79 and 55%, respectively). For nalidixic acid, enrofloxacin and ampicillin, resistance was observed in 34, 15 and 20% of the isolates, respectively. More than one-third of the strains was resistant to at least three antimicrobial drugs. A Thr86Ile modification in GyrA was observed in the enrofloxacin-resistant strains studied. The multiresistant strains analyzed expressed the multidrug transporter CmeB at a high level. Results indicated a high prevalence of C. coli in the stomach of the French pigs examined. In addition, a high proportion of the strains was resistant to antimicrobial drugs, particularly to tetracycline and erythromycin, or were multiresistant.

Animals↗

The Chinese in Canada: a study in ethnic change with emphasis on gender roles.

The authors investigated the impact of ethnic change experienced by Chinese Canadian couples on gender-role attitude, household task-role expectations and performance. The authors presented acculturation and Chinese ethnic identification as the two discriminant facets of ethnic change. Results indicated a nonsignificant role of acculturation in bringing about modifications of the gender-role attitudes of husbands and of their household task-role expectations. In contrast, the acculturation of Chinese Canadian wives proved to be a significant factor in promoting more modern (less traditional) gender-role attitudes, which in turn led to role expectations that they should contribute less to the performance of the tasks that traditionally fall in the female domain whereas their husbands should contribute more. Subsequent results also revealed that the acculturation of wives was directly linked to the role expectation that they should assume a greater share of responsibility in taking care of the traditionally husband-responsible tasks whereas their husbands should contribute a smaller share. Moreover, Chinese ethnic identification emerged as a significant determinant of husbands' gender-role attitudes and influenced their role expectation that husbands should contribute more to the performance of the tasks that traditionally fall in the male domain whereas their wives should contribute less.

Acculturation↗

Different cellular fatty acid pattern behaviours of two strains of Listeria monocytogenes Scott A and CNL 895807 under different temperature and salinity conditions.

Cells of two strains of Listeria monocytogenes CNL 895807 and Scott A were grown to late exponential phase at different growth temperatures (37, 20 and 4 degrees C) with or without NaCl (7%), and their fatty acid compositions were analysed. The results showed that low thermal adaptation response of L. monocytogenes CNL was different than that of the Scott A strain, and it was based on both an increase of anteiso-branched-chain fatty acids and a significant decrease of straight-chain fatty acids. However, the main modifications observed in the Scott A strain when grown at a low temperature were a decrease of the proportion of ai17:0 and an increase of ai15:0. In hyperosmotic medium and over the entire temperature range (4 degrees C, 20 degrees C and 37 degrees C) the two L. monocytogenes strains showed a cellular fatty acid profile dominated by ai15:0. In addition, a decrease of the two major straight-chain fatty acids (14:0 and 16:0) was observed in the CNL strain. These results demonstrated that the CNL strain showed different behaviours of low thermal and salt adaptation to maintain membrane fluidity, which are based both on an increase of anteiso-branched-chain fatty acids, and a significant decrease of straight-chain fatty acids.

Adaptation, Physiological↗

The therapeutic approach to osteoarthritis.

Ideally, treatment is based on etiology, if possible on pathophysiology, and in practice on anatomical and clinical findings. A systematic search for the etiological factors of osteoarthritis (OA) shows that the various mechanisms are frequently associated. Etiological treatments are rare. We may mention acetabular tectoplasty in hip dysplasia with minimal joint space narrowing. Valgus osteotomy would also be indicated for early medial tibiofemoral OA in genu varum if we had definite proof that, if left untreated, this deformity inevitably leads to clinically severe OA. This is not the case. One of the limitations of this etiological treatment lies in the fact that we do not know which patients are at risk of developing painful OA. Instead, certain risk factors for OA are known, so that primary and secondary prevention of the disease is possible. While age, sex and genetic predisposition are not amenable to preventive action, the same does not apply to the following factors: obesity, sports, and occupational activity. Thanks to in vitro studies of cultured normal and osteoarthritic chondrocytes and to experimental models of OA in animals, the pathophysiological mechanisms of OA are beginning to be better known. The prospect thus arises of "therapeutic manipulations" of precise pharmacological targets, even if it is still too soon to speak of true pathophysiological treatment of this disease. For instance, various interventions along the IL-1 pathway can be envisaged and have all been tested in animals. In practice, treating OA means taking into consideration its various signs: pain which appears to be mechanical and more or less chronic, joint stiffness, instability, effusion, and--the consequence of these symptoms--the professional, social and personal handicap of the patient. The treatment of OA must be approached from a global perspective, associating whenever possible symptomatic treatment, disease-modifying treatment, education and rehabilitation. In other words, the treatment of OA requires an overall approach, associating pharmacological and non-pharmacological modalities.

Aging↗

Bent spine syndrome: computed tomographic study and isokinetic evaluation.

Primary acquired lumbar kyphosis of the adult, or bent spine syndrome, is probably secondary to late-onset muscle dystrophy preferentially involving the paravertebral muscles. In order to better define the extent of this myopathy, we compared spinal computerized tomography scans and muscle force, power, and fatigability, assessed by isokinetic tests, of the spinal erector and pelvic and shoulder girdle muscles in 23 patients with primary acquired lumbar kyphosis (20 women and 3 men, mean age 72.8 years) and 15 matched control subjects. Patients had decreased spinal and shoulder muscle density. Force, power, and work done were reduced in their paravertebral muscles, whereas in the scapular and gluteus medius muscles only work done after a series of 20 rapid movements showed a decrease. Primary acquired lumbar kyphosis in the adult may be considered as a late-onset girdle myopathy with subclinical involvement of the muscles of the pelvic and shoulder girdles.

Aged↗

Can ischemic hip disease cause rapidly destructive hip osteoarthritis? A case report.

Avascular osteonecrosis of the femoral head (AONFH) usually goes through the four stages described by Arlet and Ficat: normal radiographs, heterogeneity and sclerosis of the femoral head, subchondral fracture with an individualized sequestrum, and secondary osteoarthritis. Arlet and Ficat individualized a specific pattern of AONFH which they called ischemic hip disease, in which cartilage damage seen as concentric joint space loss precedes the bony alterations. Although radiological and pathological studies of ischemic hip disease have been published, no clinical data are available. We report the case of a 65-year-old man admitted for a 1-month history of severe hip symptoms with concentric joint space loss but no osteophytes. Laboratory tests and examination of fluid aspirated from the hip ruled out septic arthritis and inflammatory hip disease. Two magnetic resonance imaging (MRI) studies done 1 month apart showed diffuse edema involving not only the femoral head but also the neck and trochanter, as well as major synovial hypertrophy. This atypical MRI appearance prompted synovial membrane and pertrochanteric core biopsies, which showed reactive synovitis and stage IV osteonecrosis, respectively. The pain, disability, and joint space loss worsened. Total hip arthroplasty was performed 1 month after the biopsy. Histological examination of the femoral head showed diffuse necrosis; no evidence of another condition was found on histological sections of the entire synovial membrane. This case corroborates the hypotheses put forward by Lequesne that some cases of rapidly destructive hip osteoarthritis may be ascribable to ischemia.

Acetaminophen↗

Intraosseous circulation from physiology to disease.

Blood flow within bones is unique in two ways: (1) the blood circulates within a closed cavity in which pressure must remain constant, a feat achieved in part thanks to the considerable distensibility of the intraosseous vessels and, above all, veins; (2) the intraosseous circulation allows traffic of minerals between the blood and bone tissue and sends the blood cells produced within the bone marrow into the systemic circulation. In contrast, the arterioles and capillaries within bones have the same anatomic structure as those located elsewhere in the body and are susceptible to arteriosclerosis, arteritis, or thrombosis. The mechanisms that regulate blood flow within bone are incompletely understood, probably because they are difficult to study in vivo. The cytokines and growth factors that regulate intraosseous angiogenesis also regulate bone remodeling, and close links exist between the blood supply to bone and bone formation and resorption: most diseases characterized by increased bone resorption are associated with increased bone vascularization. The vascular bud located at the center of bone multicellular units (BMUs) may determine the timing of bone resorption and bone formation. Avascular bone necrosis and bone infarction may result from acute blood vessel occlusion (thrombosis, lipid emboli, fat cell hypertrophy with compression of intraosseous capillaries), whereas arteriosclerosis may contribute to the development of osteoporosis.

Bone and Bones↗

Cellular lipid fatty acid pattern heterogeneity between reference and recent food isolates of Listeria monocytogenes as a response to cold stress.

Cells of four reference strains (Scott A, LO 28, CNL 895807 and ATCC 19115) and of five recent food isolates (A00M011, A00M018, A00M087, A00M092 and A00M123) of Listeria monocytogenes were grown until late exponential phase in Brain Heart Broth at two different temperatures (37 degrees C and 4 degrees C). Our results show that significant differences exist between the cellular lipid fatty acid profile of reference and recent food isolates. Like the reference strains, and in keeping with previous reports on the cellular lipid fatty acid profile of L. monocytogenes, the recent food isolates were characterised by the presence of ai15:0, i15:0 and ai17:0. In addition, the fatty acid ai13:0 was observed in all of the recent food isolates grown at 4 degrees C, whereas only two reference strains, Scott A and LO 28, showed ai13:0 in their cellular lipid fatty acid profile at 4 degrees C. When grown at 4 degrees C, the recent food isolates showed a mean aiC15/aiC17 ratio of 66, while reference strains were characterised by significantly lower ratios, ranging between 4.3 (ATCC 19115) and 28.9 (Scott A). These results showed that all of the recent food isolates, Scott A and LO28 strains use chain length and anteiso-branching (ai15:0) as their major response to cold temperature adaptation. However, the cold adaptation response of reference strains CNL 895807 and ATCC 19115 appears to be different.

Adaptation, Physiological↗