Ground reaction force patterns in knees with and without radiographic osteoarthritis and pain: descriptive analyses of a large cohort (the Multicenter Osteoarthritis Study).

OBJECTIVE: To compare ground reaction force patterns (GRF) during walking among legs defined by presence or absence of knee pain and/or radiographic knee osteoarthritis (ROA). METHOD: Principal component analysis extracted major modes of variation (PCs) in GRF data from the Multicenter Osteoarthritis Study during self-paced walking. Legs were categorized as pain + ROA (n = 168), ROA only (n = 303), pain only (n = 476), or control (n = 1877). Relationships between group and GRF PCs were examined using Generalized Estimating Equations, adjusted for age, sex, body mass index, race, and clinic site with and without additional adjustment for gait speed. RESULTS: With or without speed adjustment, pain + ROA had flatter vertical GRF waveforms than control (speed adjusted PC2 difference [95%CI]: -66 [-113,-20]), pain + ROA and ROA only had higher lateral GRF at impact and greater mid-stance medial GRF than control (speed adjusted PC3 difference: 9 [3,16] and 6 [2,10], respectively), and ROA only had higher early vs late medial GRF than control (speed adjusted PC2 difference: 7 [2,13]). Pain only had flatter vertical GRF waveforms and a smaller difference between anterior and posterior GRF than control only without speed adjustment. CONCLUSION: In this large sample, sustained mid-stance loading and higher impact loads were identified in legs with ROA or ROA and pain, even when adjusting for differences in gait speed and other confounders. While it remains to be seen whether these features precede or result from ROA and pain, the presence of these patterns in the speed-adjusted models could have implications on gait interventions aimed to change joint loading.

Prevalence of and risk factors for HIV-associated neuropathy in Melbourne, Australia 1993-2006.

OBJECTIVES: The aim of the study was to describe the prevalence of and risk factors for HIV-associated sensory neuropathy (HIV-SN) in 2006 [the era of stavudine, didanosine and zalcitabine (dNRTI)-sparing highly active antiretroviral therapy (HAART)] and to compare our findings with data obtained in the same clinic in 1993 (pre-HAART) and 2001 (frequent use of dNRTI-containing HAART). METHODS: This was a cross-sectional comparative study using convenience sampling. HIV-positive adults attending a tertiary referral clinic over a 2-week period were screened for HIV-SN using the AIDS Clinical Trials Group screening tool. HIV-SN was defined as present if the patient had both neuropathic symptoms and abnormal signs. Demographic, clinical, laboratory and treatment data were considered as possible risk factors for HIV-SN, and results were compared with data obtained in the same clinic in 1993 and 2001. RESULTS: One hundred patients were screened. The prevalence of HIV-SN was 42%, which was unchanged since 2001 (44%) despite a significant reduction in the use of dNRTIs. HIV-SN remained much more common than in 1993 (42% vs 13%; P<0.0001). The only independent associations with HIV-SN in 2006 were increasing patient age and a history of exposure to either stavudine or indinavir. This compares with 1993 when neuropathy was increased in those with Mycobacterium avium complex infection, and 2001 when patient age and use of stavudine and didanosine were the independent associations with HIV-SN in this clinic. CONCLUSIONS: HIV-SN remained common among ambulatory patients in 2006 (42% prevalence) despite a significant reduction in the use of dNRTIs. In addition to patient age and stavudine exposure, indinavir use may be a risk factor for HIV-SN.

Clinical response to glatiramer acetate correlates with modulation of IFN-gamma and IL-4 expression in multiple sclerosis.

OBJECTIVE: To determine whether glatiramer acetate (GA)-induced lymphoproliferation and IFN-gamma and IL-4 modulation correlate with the clinical response in multiple sclerosis (MS). BACKGROUND: GA therapy involves the induction of anti-inflammatory cytokine shifts. However, it is not known whether this response correlates with the clinical outcome. METHODS: Thirty-six relapsing-remitting (RR) MS patients were treated with GA for at least two years, and classified clinically as GA-responders (GA-R=22) or hypo/non-responders (GA-HR/NR = 14). Proliferation of peripheral blood mononuclear cells (PBMC) to GA and Tetanus toxoid (TT), as well as IL-4 and IFN-gamma ELISPOT, were performed. FINDINGS: There was no difference in PBMC proliferation to GA or TT between GA-R and GA-HR/NR before and during treatment (P>0.05). The mean number of IFN-gamma ELISPOTS in unstimulated, TT and anti-CD3/CD28-stimulated PBMC was lower among GA-R (unstimulated: GA-R =10.1+/-6.21 (n=22) versus GA-HR/NR=17.8+/-12.7 (n=14), P=0.04; TT-GA-R =12.2+/-4.06 (n=12) versus GA-HR/NR=26.8+/-21.0 (n=8), P=0.028; anti-CD-3/CD28 GA-R=217.3+/-140.4 (n=22) versus GA-HR/NR=368.5+/-170.1 (n=14), P=0.006). In contrast, the number of IL-4 ELISPOTS remained unchanged in the GA-R group, but was progressively reduced in the GA-HR/NR group during GA therapy (GA-HR/NR IL-4: pre-Rx: 59+/-34 versus 22+/-11 at 12 months (n =6), P=0.0429). The IL-4/ IFN-gamma ratio in anti-CD3/CD28-stimulated PBMC was significantly higher among GA-R compared to GA-HR/NR (P=0.0474). INTERPRETATION: Lymphoproliferation to GA did not differentiate GA-R from GA-HR/NR. However, reduced IFN-gamma expression and stable IL-4 expression in anti-CD3/CD28-stimulated PBMC, and an increased IL-4/IFN-gamma ratio was associated with favorable clinical response. More data are needed to validate the prospective use of IL-4/IFN-gamma expression in PBMC as a biomarker of clinical response to GA for individual patients.

[D.L.vo n. 626/94 - Musculoskeletal diseases caused by use of micropipette in laboratory]. / D.L.vo n. 626/94--Malattie muscolo-scheletriche da impiego di micropipette in laboratorio.

The use of manual pipettes has been associated with a high prevalence of upper extremity and neck cumulative trauma disorders (CTD's) and work-related musculoskeletal disorders (WMSD's) among laboratory workers. The primary risk factor for these disorders are poor ergonomics in three specific areas: posture, repetition and force. Federal agencies have issued guidelines for pipetting practices to reduce the risk of injury and WMSD's. Pipette manufacturing have responded to the problem by improving the ergonomics and buttons and plungers that require less forces during operations. Another problem was still open with the traditional axial-design pipette: deviation of body or extremity from an ergonomically favourable neutral position. The new generation of micropipettes solves this problem.

Optimization of the safety and efficacy of interferon beta 1b and azathioprine combination therapy in multiple sclerosis.

We conducted an open-label pilot clinical trial to evaluate the safety and efficacy of adding oral azathioprine to the treatment regimen of 15 multiple sclerosis patients breaking through monotherapy with interferon beta-1b. There were no serious adverse events. Gastrointestinal side effects and leukopenia were the most common adverse events and limited dose escalation. There was a 65% reduction in the number of gadolinium-enhanced magnetic resonance imaging (MRI) lesions on combination therapy compared to the baseline values (P =0.003). A total WBC count less than 4800/mm3 was the best predictor of MRI response.

Multidisciplinary HIV adherence intervention: a randomized study.

Maintaining greater than 95% adherence to antiretroviral medication is necessary in order to have the greatest therapeutic impact on HIV infection. Furthermore, evidence suggests that adherence rates of between 70% and 89% are significantly associated with viral rebound and the development of drug resistance. Adherence rates at and above the 95% level are difficult for patients to achieve and maintain. Our aim was to determine if an adherence intervention could improve adherence among patients attending an ambulatory care clinic at a large public hospital. The intervention was delivered by a multidisciplinary team of health care professionals and consisted of education coupled with the provision of devices designed to assist patient memory and adherence. A crucial component of the intervention consisted of the identification of patient specific barriers to adherence and the development of strategies to circumvent these problems. Adherence was assessed using patient self-report over the past 4, 7, and 28 days and by calculation of the Morisky score. The study was conducted as a randomised controlled trial using the stepped wedge design with a total of 68 subjects randomised to receive the intervention over a 20-week period. Adherence before and after the intervention formed the analysis. There was a significant decrease in the number of missed doses over the past 4 (1.9 to 1.0, p < 0.001), 7 (3.0 to 1.8, p < 0.001) and 28 (7.4 to 4.2, p < 0.001) days and a decrease in the Morisky score, indicating an improvement in medication taking behaviour (1.3 to 0.5 p < 0.001).

Randomized trial of an adherence programme for clients with HIV.

Our aim was to determine if a comprehensive adherence package improved self reported adherence to antiretroviral therapy. The adherence package included an education programme, individualized planning of regimens, and the opportunity for a patient to choose from a number of adherence aids and reminder devices. A randomized step wedge design was used. Forty-three individuals were randomized to begin the intervention over a five-month period. There was a substantial fall in the number of missed doses reported for the last four days (0.76 to 0.38, P =0.03) and last seven days (1.5 to 0.74, P =0.005) but not for the last 28 days (2.5 to 2.5, P =0.63). There was no statistical difference in the viral load or CD4 lymphocyte count in the period before or after the intervention. The Morisky score during the pre and post intervention periods was significantly different (P =0.006), 2.9 (SD 0.9) and 3.3 (SD 0.8) respectively. This adherence package improved self reported adherence during the last four and seven days.

New approaches for the prevention of airway infection in ventilated patients. Lessons learned from laboratory animal studies at the National Institutes of Health.

Despite early diagnosis and appropriate antibiotic therapy, ventilator-associated pneumonia (VAP) remains the leading cause of death from hospital-acquired infection in ventilator-dependent patients. Strategies to prevent bacterial colonization of the trachea and lungs are the key to decrease mortality, hospital length of stay, and cost. It is well established that the VAP can result from entry of infected oropharyngeal/gastric secretions into the lower airways. Aspiration may occur during 1) intubation, 2) mechanical ventilation through leakage around the tracheal tube cuff, 3) suctioning of the tracheal tube when bacteria can detach from the biofilm within the tube, or 4) areosolization of bacterial biofilm during mechanical ventilation through the tracheal tube or the ventilator circuit biofilm. From experimental studies in sheep, we drew 3 relevant conclusions: 1) The tracheal tube and neck should be oriented horizontal/below horizontal to prevent aspiration of colonized secretions and subsequent bacterial colonization of the lower respiratory tract. 2) Continuous aspiration of subglottic secretions (CASS) can lower bacterial colonization of the respiratory tract, but at the price of severe tracheal mucosal damage at the level of the suction port. 3) Coating the interior of the tracheal tube with bactericidal agents can prevent bacterial colonization of the tube surface and of the entire respiratory circuit, during 24 hours of mechanical ventilation.

Effect of combined IFNbeta-1a and glatiramer acetate therapy on GA-specific T-cell responses in multiple sclerosis.

The combined treatment with interferon beta (IFNbeta) and glatiramer acetate (GA) is of current interest in multiple sclerosis (MS). The therapeutic effect of GA in MS is believed to be mediated by GA-specific Th2 cells. IFNbeta has a significant anti-proliferative effect on GA-induced lymphoproliferation in vitro. Therefore, we examined the possibility that IFNbeta may interfere with the generation and phenotype of GA T-cell responses in MS patients receiving combined therapy. Sixty-six GA-specific T-cell lines (TCL) were generated ex vivo from five MS patients enrolled in an open-label dinical trial of combined IFNbeta/GA treatment. Controls included 83 pretreatment and 131 on-treatment GA-TCL from 11 MS patients treated with GA only, and five GA-TCL generated from four patients receiving IFNbeta-1a monotherapy. IFNgamma and IL-5 (markers of Th1 and Th2 responses, respectively) were assayed by ELISA in GA-TCL supematants. Th1/Th2 bias was defined by the IFNgamma/IL-5 level ratio ( >2 = Th1 bias, <0.5 = Th2 bias, and 0.5-2 = Th0 bias). The frequency with which GA-reactive TCL were generated was 37.0% for the patients in the combination trial compared to 33.3% in the patients receiving GA alone. The mean stimulation index of the GA-TCL was 8.41 (range 2-42) for the combination compared to a mean of 6.29 (range 2-37) for the GA-treated group--a nonsignificant difference. Mean GA-TCL IFNgamma production was significantly lower in all treatment groups compared to pretreatment IL-5 levels were enhanced in all treatment groups compared to pretreatment levels, but the change was not statistically significant. The Th1/Th0/Th2 distribution of GA-TCL was 7%/30%/63% for the GA+IFNbeta group, 8%/9%/83% for the GA group, compared to 48%/21%/31% pre-GA treatment. All five GA-TCL from the IFNbeta-1a monotherapy patients were Th2-biased. We conclude that IFNbeta-1a does not affect the generation of GA-reactive T cells in vivo. Although more Th0 G4-TCL occurred with combination therapy than with G4 treatment alone, both groups shared an overall Th2 bias. Therefore, we speculate that combined therapy is unlikely to reduce the efficacy of GA treatment in MS.

Glatiramer acetate induces a Th2-biased response and crossreactivity with myelin basic protein in patients with MS.

Glatiromer acetate (GA) is an approved treatment for multiple sclerosis (MS). The proposed mechanism of action is the induction of GA-specific T cells characterized by protective anti-inflammatory Th2 response. We tested this hypothesis in 11 MS patients treated with GA from 1-19 months. Interferon-gamma and IL-5 (markers of Th1 and Th2 responses respectively) were assayed by ELISA in GA-specific T-cell lines (TCL) supernatants. Th1/Th2 bias was defined based on the ratio of IFN-gamma/IL-5 secretion. Fifty-eight pre-treatment and 75 on-treatment GA-specific TCL were generated. On-treatment mean IL-5 levels in GA-TCL increased significantly, whereas those for IFN-gamma were markedly reduced. Consequently, the ratio of IFN-gamma IL-5 also shifted in favor of a Th2 response. The percentage of GA-TCL classified as Th1 was decreased, whereas those classified as Th2 increased on-treatment as compared to pre-treatment. Some GA-specific TCL, (approximately 25%) generated during treatment secreted predominantly IL-5 in response to MBP and the immunodominant MBP peptide 83-99, indicating that these crossreactive antigens can act as partial agonists for GA-reactive TCL. These results strongly suggest that the mechanism of action of GA in MS involves the induction of crossreactive GA-specific T cells with a predominant Th2 cytokine profile.

Nursing management of MS patients receiving interferon beta-1b therapy.

In 1993, recombinant interferon beta-1b (Betaseron, Berlex Laboratories) was approved by the Food and Drug Administration as a treatment for relapsing-remitting multiple sclerosis (MS). Betaseron is the first therapeutic agent licensed for use with therapeutic patients with MS in more than 20 years. Many patients and their families have expressed great interest in obtaining information about this agent. In response, MS centers throughout the United States have developed Betaseron training programs. This article describes how rehabilitation nurses can educate patients and families about Betaseron.

Investigation of porphyrins and metalloporphyrins using two-step laser mass spectrometry.

Laser desorption time-of-flight mass spectrometry with laser postionization at 193 nm has been used to study a series of selected porphyrins and metalloporphyrins. Molecular ions are predominantly formed under soft ionization conditions, with extensive fragmentation of the peripheral substituents being observed under hard ionization conditions. Cu-octaethylporphyrin is found to exhibit anomalous demetallation at this ionization wavelength. At high ionization laser fluences it is also possible to observe extensive fragmentation of the porphyrin macrocycle. Much of the observed fragmentation can be understood with reference to previous studies using electron impact (EI) ionization. The stability of the porphyrin nucleus allows the fragmentation of the side chains to be examined. As in earlier EI studies dehydration products are observed in the mass spectra of hematoporphyrin IX. These products are shown to be thermally induced during infrared laser desorption, rather than fragments arising from photoionisation. The flexibility of this two-step laser mass spectrometric approach has allowed the analysis of chlorophyll a directly from an organic matrix. The data obtained suggest that information concerning the interaction between adsorbate and substrate can be extracted.

A database for mucositis induced by cancer chemotherapy.

Ulcerative mucositis has become an increasingly important toxicity of antineoplastic therapy. In an effort to establish mucositis risk prediction for specific cancer chemotherapy regimens, a 25 field database was developed. This paper describes the rationale and methodology for creation of the database and instructions for access to it via the Internet.