Quadriceps weakness in knee osteoarthritis: the effect on pain and disability

OBJECTIVES: (1) To determine the importance of quadriceps strength, structural change, and psychological status in terms of knee pain in the community. (2) To determine the relative importance of quadriceps function, structural change, and psychological status with respect to disability in subjects with knee pain. METHODS: 300 men and women with pain and 300 controls without pain (aged 40-79) were seen. Isometric quadriceps strength (MVC) was measured and muscle activation was assessed by twitch superimposition. Disability (Western Ontario McMaster Osteoarthritis Index (WOMAC)) and anxiety and depression were assessed (Hospital Anxiety and Depression Index (HAD)). Radiographs were obtained of the tibiofemoral and patellofemoral joints and total score for osteophyte, narrowing, and sclerosis calculated for each knee. RESULTS: Subjects with knee pain had lower voluntary quadriceps strength than those without pain (p < 0.005). Quadriceps activation was also lower (p < 0.005), but did not fully explain the reduction in strength. When analysed by multiple logistic regression: quadriceps strength (odds ratio 18.8, CI 4.8, 74.1 for MVC < or = 10 kgF); depression (odds ratio 2.4, CI 1.0, 5.5 for HAD score > or = 8); and radiographic change (odds ratio 4.1, CI 1.9, 8.6 for radiographic score > or = 4) were independently associated with pain. In those with knee pain, disability was independently associated with quadriceps strength (odds ratio 8.2, CI 1.5, 44.4 for MVC < or = 10 kgF) and depression (odds ratio 6.2, CI 2.1, 18.0 for HAD score > or = 8); but not with radiographic score. CONCLUSIONS: Quadriceps strength is strongly associated with knee pain and disability in the community, even when activation and psychological factors are taken into account. This has important therapeutic implications.     

Scientific articles and national medical cultures: A comparison of Russian and American medical journals

Medical journals are products of national medical cultures, which influence the organization of medical research and the readiness to employ different research methodologies. A content analysis was undertaken to ascertain the characteristics of scientific papers in nine Russian and three American medical journals published in 1992. The American medical journals were thriving, both in appearance, and with research contributions coming from a decentralized national system of research institutions and also from European and other international research centers. Much of American medical research is “big science” based on collaborative efforts of researchers at a number of institutions. Russian medical journals, in contrast, were more parochial in content, reporting mainly local research, with several primary journals serving as outlets for endeavors of sponsoring institutes. While Russian medical culture did appear to discourage usage of classical random experimental designs, the choice of research methodologies proved to be influenced more by medical specialization than by national culture.     

Wet chemical synthesis of low bulk density aluminium hydroxide powder

Fine, low bulk density aluminium hydroxide powdered gel was prepared by the mild base hydrolysis of an aqueous solution of aluminium sulfate with hydrazine hydrate. Parameters such as method of addition of reactant, initial concentration of Al³⁺, mole ratio, final pH and hydrolysis temperature have a profound effect on the lightness and particle size of the powder. Optimized conditions showed that the final pH, Al³⁺ concentration and method of addition of reactant have a major contribution on the formation of lighter grade powder. Experiments conducted using other bases also produced lighter particles under similar conditions. Deviation from the optimized conditions led to formation of a higher bulk density product. Copyright © 2003 Society of Chemical Industry     

Signalling initiated with CD4-TCR or TCR-TCR interactions: comparison of tyrosine phosphorylation patterns and CD45 effects

LY 300164 [7-acetyl-5-(4-aminophenyl)-8,9-dihydro-8-methyl-7H-1,3-dioxolo(4, 5H)-2,3-benzodiazepine], administered intraperitoneally up to 2 mg/kg, did not influence the threshold for electroconvulsions. In doses of 2.5-4 mg/kg, LY 300164 significantly raised the threshold. In subprotective doses against electroconvulsions, this excitatory amino acid receptor antagonist enhanced the protective activity of intraperitoneally given valproate, carbamazepine and diphenylhydantoin against maximal electroshock-induced convulsions in mice. The anticonvulsive action of phenobarbital was potentiated by LY 300164 only at 2 mg/kg. The non-N-methyl-D-aspartate receptor antagonist did not affect the plasma levels of the antiepileptic drugs, so a pharmacokinetic interaction is not probable. Combined treatment with LY 300164 (2 mg/kg) and the antiepileptics studied (providing 50% protection against maximal electroshock) did not impair the motor performance of mice, evaluated in the chimney test. Valproate, at its ED50 of 280 mg/kg against maximal electroshock, produced motor impairment. As shown in the passive avoidance task, combination of LY 300164 (2 mg/kg) with valproate or diphenylhydantoin resulted in impairment of long-term memory. Alone among the antiepileptics, valproate (280 mg/kg) and phenobarbital (28.5 mg/kg) disturbed long-term memory. The results suggest that blockade of glutamate-mediated events via non-NMDA receptors leads to enhancement of the anticonvulsive activity of conventional antiepileptics. Some combinations of LY 300164 with antiepileptic drugs were superior to these antiepileptics alone in terms of their lack of adverse effects.     

Relationships among absorbents on the reduction of grass silage effluent and silage quality

Effluent from grass silage is a threat to water quality and a loss of valuable forage nutrients from dairy farms. Absorbents potentially reduce effluent loss when weather conditions are not ideal for field wilting. The objective was to determine the effectiveness of various absorbents at reducing silage effluent. First-harvest, direct-cut, perennial grass forage was ensiled with and without absorbents in medium-sized experimental silos for 3 consecutive yr. Silos contained 4.54 kg of grass and one of the following feed quality absorbents: 10% rolled barley, 10% dried and pelleted beet pulp, or alfalfa cubes at 10, 20, or 30%. Nonfeed quality absorbents used were 1% starch grafter polymer, 1% bentonite clay, and 10% newspaper. Silage from direct-harvest control forage produced the highest effluent losses, but the wilting of grass prior to ensiling or the mixing of grass with 30% alfalfa cubes nearly eliminated effluent. Silage pH was lowest when rolled barley or beet pulp was used as the absorbent and was highest for wilted grass. Silage dry matter was increased by wilting and by the use of barley, beet pulp, newspapers, or alfalfa cubes as absorbents. The addition of 10% newspaper greatly reduced in vitro dry matter digestibility and crude protein. Increased water-soluble carbohydrate concentrations were found for silage from grass forage treated with rolled barley, beet pulp, or alfalfa cubes prior to ensiling. Although bentonite clay and newspapers reduced effluent losses, greater water-soluble carbohydrate losses were found for these treatments compared with the direct control. Alfalfa cubes were found to be effective absorbents and did not reduce grass silage quality.     

Outcome of Graves' disease after antithyroid drug treatment in Taiwan

The outcome of Graves' disease after treatment with antithyroid drugs (ATDs) varies widely among countries, and large-scale studies in Asia are rare. We investigated the associations of various clinical and laboratory features with the outcome of ATD therapy for Graves' disease in Taiwan. A total of 210 patients (177 women, 33 men; mean +/- SD age, 41.7 +/- 15.1 yr) treated with ATD in Taiwan were included. ATD therapy started with methimazole 30 mg daily or propylthiouracil 300 mg daily and was continued until a euthyroid state was achieved. Afterwards, 154 patients received a maintenance dose of ATD alone, while 56 patients received a combination of an ATD and thyroxine (L-T4). Patients were considered to be in remission if they remained in a euthyroid state for more than 2 years after drug withdrawal. The mean follow-up periods were 45.0 +/- 20.9 months for patients with remission and 30.4 +/- 19.8 months for those with relapse. Relapse occurred in 126 (60%) patients during the follow-up period, within 3 months after drug withdrawal in 47 (37%), and within 6 months in 60 (46%). The relapse rate was 100% among patients with two or more previous relapses. Patients with a second occurrence had a higher relapse rate than those with a first occurrence (84% vs 43%). Past history of recurrence, goiter size, thyroid-stimulating hormone level and thyrotropin-binding inhibition immunoglobulin activity at the end of ATD treatment were independently associated with relapse. Prolonged duration of treatment did not yield better results in patients with larger goiters or a history of recurrence, or both. Combination therapy with L-T4 yielded similar results to those achieved with ATD treatment alone. In conclusion, the relapse rate of Graves' disease after ATD treatment in Taiwanese patients was high, especially in those with a history of recurrence. The treatment duration and drug regimen did not affect the outcome.     

Review of dental materials citations: Part A, January to June 1995

The study was conducted by the known tendencies of increased stress-susceptibility and metabolic disorders in individuals with hypertrophied muscles due to innate factors or intensive exercise which can induce the overtraining syndrome. Using an animal model, muscle-associated cells from normal (N) and hypertrophic (H) skeletal muscle (m.semitendinosus) were examined in their resting and phorbolmyristate acetate (PMA) stimulated oxidation of dihydrorhodamine (DHR) as well as cathepsin B and L activities. Phagocytes were phenotyped by their casein receptors (CR) and fibroblasts by their surface collagens (I and IV). The portion of CR-cells in single cell suspension was 4-8% and 1-3% in H and N. The CR-cells were enriched by 200 g centrifugation and cultured for 5 days with and without cortisol (C), norepinephrine (NE) and indomethacin (I). NE suppressed dose-dependently CR-expression in N, with increase in H occurring. C, NE and I elevated cathepsin activities only in N. PMA stimulated DHR oxidation in H and N 5- and 2-fold. Only the oxidative rate in N reacted to C, NE and I significantly. The data suggest that the response of muscle-associated cells from hypertrophied and normal muscles to signals released in stress-coping significantly differs.     

KSR stimulates Raf-1 activity in a kinase-independent manner

Kinase suppressor of Ras (KSR) is an evolutionarily conserved component of Ras-dependent signaling pathways. Here, we find that murine KSR (mKSR1) translocates from the cytoplasm to the plasma membrane in the presence of activated Ras. At the membrane, mKSR1 modulates Ras signaling by enhancing Raf-1 activity in a kinase-independent manner. The activation of Raf-1 is mediated by the mKSR1 cysteine-rich CA3 domain and involves a detergent labile cofactor that is not ceramide. These findings reveal another point of regulation for Ras-mediated signal transduction and further define a noncatalytic role for mKSR1 in the multistep process of Raf-1 activation.