Magnetic Field Dependence of CDW Phases in (Per)2M(mnt)2 (M = Pt, Au)

Recently the authors discovered that the suppression of the charge density wave (CDW) ground states by high magnetic fields in the organic conductor series (Per)₂M(mnt)₂ is followed by additional high field, CDW-like phases. The purpose of this paper is to review these compounds and to consider the relevant parameters of the materials that describe the manner in which the CDW ground state may undergo new field induced changes above the Pauli limit.     

New insights into the role of follicle-stimulating hormone in reproduction

Follicle-stimulating hormone (FSH) has been considered essential for normal ovarian follicular development and spermatogenesis. Although this concept remains valid, the recent reports of defects in genes encoding FSH and its receptor (FSHR) have altered the concepts, particularly with regard to the role of FSH in spermatogenesis. Complete FSH resistance caused by a mutation of the FSHR gene has demonstrated that normal FSH action is an absolute requirement for female fertility, but spermatogenesis and male fertility are possible without FSH action. Thus, while normal ovarian function is critically dependent on normal FSH action, male fertility is relatively independent of this hormone. The finding contradicts the potential of inhibition of FSH secretion or action as a means of male contraception.     

Progression of cochlear and retinal degeneration in the tubby (rd5) mouse

Various molecules expressed on the surface of platelets have been shown to mediate the protective or deleterious role of these cells in immuno-inflammatory mechanisms. Increasing evidence points to the involvement of the cell adhesion molecules, gpIIb-IIIa, P-selectin, CD31, LFA-1, and CD36 in the interaction between platelets and endothelial cells as well as other cell types. The possible role of these molecules in the ability of platelets to support endothelium and to protect against tumour necrosis factor mediated cytolysis or parasitic invasion are reviewed. The involvement of platelets as effectors of tissue damage in cerebral malaria, lipopolysaccharide induced pathology, and pulmonary fibrosis is also discussed. This has then been extended to include the intercellular mechanisms underpinning their pathogenic role in metastasis, transplant rejection, stroke, brain hypoxia, and related conditions. A better understanding of the complex regulation and hierarchical organisation of these various platelet adhesion molecules may prove useful in the development of new approaches to the treatment of such diseases.     

Desmoid tumor of the thoracic wall. A case manifesting as painful stiffness of the shoulder

BACKGROUND: Desmoid tumors are uncommon fibromatous tumors arising from musculoaponeurotic tissue characterized by spindle cell fibroblast and myofibroblast proliferation. The cause is unknown (trauma, hormonal factors, genetic anomaly...). Locally invasive, they tend to recur increasing morbidity or even mortality. CASE REPORT: Stiff shoulder resulting from blockage of the scapulothoracic articulation was the inaugural sign. Three-phase bone scintigraphy demonstrated early uptake in the soft tissue in contact with the scapula. Magnetic resonance imaging and biopsy confirmed the diagnosis of desmoid tumor. Complete resection was performed. No adjuvant radiotherapy nor hormone treatment were given since no antiestrogen receptor antibodies were identified on the surgical specimen. DISCUSSION: The clinical manifestation (stiff shoulder) and the scapular localization observed in this case are unusual for desmoid tumors. Initially tendinopathy of the shoulder, acromio-clavicular arthropathy and capsular retraction of the shoulder joint had been entertained. Early diagnosis and wide surgical resection are indicated in desmoid tumors.     

1997 Volvo Award winner in clinical studies. Degenerative lumbar spondylolisthesis with spinal stenosis: a prospective, randomized study comparing decompressive laminectomy and arthrodesis with and without spinal instrumentation

STUDY DESIGN: This prospective study analyzed the influence of transpedicular instrumented on the operative treatment of patients with degenerative spondylolisthesis and spinal stenosis. OBJECTIVES: To determine whether the addition of transpedicular instrumented improves the clinical outcome and fusion rate of patients undergoing posterolateral fusion after decompression for spinal stenosis with concomitant degenerative spondylolisthesis. SUMMARY OF BACKGROUND DATA: Decompression is often necessary in the treatment of symptomatic patients who have degenerative spondylolisthesis and spinal stenosis. Results of recent studies demonstrated that outcomes are significantly improved if posterolateral arthrodesis is performed at the listhesed level. A meta-analysis of the literature concluded that adjunctive spinal instrumentation for this procedure can enhance the fusion rate, although the effect on clinical outcome remains uncertain. METHODS: Seventy-six patients who had symptomatic spinal stenosis associated with degenerative lumbar spondylolisthesis were prospectively studied. All patients underwent posterior decompression with concomitant posterolateral intertransverse process arthrodesis. The patients were randomized to a segmental transpedicular instrumented or noninstrumented group. RESULTS: Sixty-seven patients were available for a 2-year follow-up. Clinical outcome was excellent or good in 76% of the patients in whom instrumentation was placed and in 85% of those in whom no instrumentation was placed (P = 0.45). Successful arthrodesis occurred in 82% of the instrumented cases versus 45% of the noninstrumented cases (P = 0.0015). Overall, successful fusion did not influence patient outcome (P = 0.435). CONCLUSIONS: In patients undergoing single-level posterolateral fusion for degenerative spondylolisthesis with spinal stenosis, the use of pedicle screws may lead to a higher fusion rate, but clinical outcome shows no improvement in pain in the back and lower limbs.     

Inhibition of shivering increases core temperature afterdrop and attenuates rewarming in hypothermic humans

During severe hypothermia, shivering is absent. To simulate severe hypothermia, shivering in eight mildly hypothermic subjects was inhibited with meperidine (1.5 mg/kg). Subjects were cooled twice (meperidine and control trials) in 8 degrees C water to a core temperature of 35.9 +/- 0.5 (SD) degrees C, dried, and then placed in sleeping bags. Meperidine caused a 3.2-fold increase in core temperature afterdrop (1.1 +/- 0.6 vs. 0.4 +/- 0.2 degree C), a 4.3-fold increase in afterdrop duration (89.4 +/- 31.4 vs. 20.9 +/- 5.7 min), and a 37% decrease in rewarming rate (1.2 +/- 0.5 vs. 1.9 +/- 0.9 degrees C/h). Meperidine inhibited overt shivering. Oxygen consumption, minute ventilation, and heart rate decreased after meperidine injection but subsequently returned toward preinjection values after 45 min postimmersion. This was likely due to the increased thermoregulatory drive with the greater afterdrop and the short half-life of meperidine. These results demonstrate the effectiveness of shivering heat production in attenuating the postcooling afterdrop of core temperature and potentiating core rewarming. The meperidine protocol may be valuable for comparing the efficacy of various hypothermia rewarming methods in the absence of shivering.     

Immunodeficiency of aging

Aging is associated with declines in multiple areas of immune function, but to date no single mechanism has emerged as being responsible for all the observed changes. Many changes occur at different rates within individuals as well as between individuals. With advancing age there is a concomitant increase in the incidence of many infections and cancers. It is being increasingly acknowledged that autoimmune processes play a proinflammatory role in the development of many pathological conditions, such as atherosclerosis. However, direct causal relationships between specific changes in immunity and the occurrence of specific diseases are rare. There is accumulating epidemiological, in vivo and in vitro evidence to support many such direct relationships in both animals and humans. It is likely that the mechanisms underlying age-related changes in immunity are multifactorial, with both genetic and environmental factors playing a significant role. Despite the current lack of unifying theories, much active and exciting work is proceeding in the area of immune stimulation. Studies describing age-related changes in immunity, as well as the testing of interventions to reverse these changes, will continue to fill the gaps in our knowledge, leading to a more comprehensive understanding of immunosenescence.     

Do amnesics forget colours pathologically fast?

We tested amnesic and control subjects on a task which required the recognition of single, difficult to name colours, after delays ranging from 7 seconds to 120 seconds after performance of the two subject groups had been matched at the shortest delay by giving the amnesic patients longer study time. The amnesic patients showed abnormally fast forgetting over the two minute period. Furthermore, a subgroup of nine subjects with presumed damage to midline diencephalic structures (Korsakoff's syndrome) were found to forget as fast as a group of six subjects with presumed medial temporal lobe damage (herpes simplex encephalitis). These results contrast both with studies using the Huppert and Piercy procedure and those using the Brown-Peterson task, none of which have shown convincing evidence of accelerated forgetting in medial temporal lobe or diencephalic amnesia.     

Phospholipase C inhibitors attenuate arrhythmias induced by kappa-receptor stimulation in the isolated rat heart

To determine whether the phospholipase C (PLC)/inositol 1,4,5 trisphosphate (IP3)/Ca2+ pathway mediates cardiac arrhythmias induced by kappa-opioid receptor stimulation, the effects of U50,488H, a selective kappa-opioid receptor agonist, on cardiac rhythm in a isolated perfused rat heart, intracellular calcium ([Ca2+]i) in a single ventricular myocyte and IP3 production in myocytes were studied in the presence and absence of PLC inhibitors. U50,488H, the effects of which had been shown to be abolished by a selective kappa-receptor antagonist, nor-binaltorphimine, induced arrhythmias dose-dependently and increased both [Ca2+]i and IP3-production in the heart. More importantly, the effects of U50,488H were blocked by PLC inhibitors, neomycin and streptomycin. To further confirm the selectivity of action of the PLC inhibitor, the effects of another PLC inhibitor U73122 and its inactive structural analog, U73343, on cardiac rhythm in the isolated perfused rat heart were compared. The former did, while the latter did not, block the arrhythmogenic effect of U50,488H. We also determined whether the effects of kappa-receptor stimulation involves a pertussis toxin (PTX)-sensitive G-protein. We found that pretreatment with PTX at 4 microg/l for 10 min, a treatment shown to affect PTX sensitive G-protein-mediated functions, attenuated significantly the U50,488H-induced arrhythmias. The present study provides evidence that kappa-receptor stimulation-induced cardiac arrhythmias involves, at least partly, the PLC/IP3/Ca2+ pathway as well as a PTX sensitive G-protein.