Objectives: This study examined the plasma concentration of pro-inflammatory cytokine, interleukin 6 (IL-6), and anti-inflammatory cytokine, interleukin 10 (IL-10), in short-, and long-term opioid users with noncancer pain.
Materials and Methods: Adult patients with opioid therapy for noncancer pain were recruited from pain clinics at two tertiary hospital settings in Malaysia between February 2016 and March 2017. They were stratified into short- or long-term users based on opioid prescriptions ≥ 90 days per year. A 10mL blood sample was taken for the analysis of plasma concentrations of IL-6 and IL-10 and were quantified using a highly sensitive multiplex assay.
Results: Of 38 patients recruited, 24% (n = 9/38) and 76% (n = 29/38) were respectively short- and long-term opioid users. Short-term use of opioid was associated with higher levels of IL-6 (mean ± SD, 173.9 ± 13.7 pg/mL) and IL-10 (50 ± 5.8 pg/mL), whereas long-term use of opioids was associated with lower levels (no significant difference) of both cytokines IL6 (125 ± 16.1 pg/mL) and IL10 (41.3 ± 6.7 pg/mL). There was strong correlation between IL-6 and IL-10 within the same group (r² = 0.72, P < 0.05) and (r² = 0.76, P < 0.05) for short- and long-term users, respectively.
Conclusion: The duration of opioid use may modulate the level of pro-inflammatory cytokines in which it was higher in short-term use and lower in long-term use, but the effect of pain relief was similar as both cytokines were well correlated.
QUESTION/PURPOSE: Does a controlled deep-freezing temperature during irradiation help preserve the compressive mechanical properties of human femoral cortical bone allografts?
METHODS: Cortical bone cube samples, each measuring 64 mm3, were cut from the mid-diaphyseal midshaft of five fresh-frozen cadaver femurs (four male donors, mean [range] age at procurement 42 years [42 to 43]) and were allocated via block randomization into one of three experimental groups (with equal numbers of samples from each donor allocated into each group). Each experimental group consisted of 20 bone cube samples. Samples irradiated in dry ice were subjected to irradiation doses ranging from 26.7 kGy to 27.1 kGy (mean 26.9 kGy) at a deep-freezing temperature below -40°C (the recommended long-term storage temperature for allografts). Samples irradiated in gel ice underwent irradiation doses ranging from 26.2 kGy and 26.4 kGy (mean 26.3 kGy) in a freezing temperature range between -40°C and 0°C. Acting as controls, samples in a third group were not subjected to gamma irradiation. The mechanical properties (0.2% offset yield stress, ultimate compression stress, toughness, and the Young modulus) of samples from each group were subsequently evaluated via axial compression loading to failure along the long axis of the bone. The investigators were blinded to sample group during compression testing.
RESULTS: The mean ultimate compression stress (84 ± 27 MPa versus 119 ± 31 MPa, mean difference 35 [95% CI 9 to 60]; p = 0.005) and toughness (3622 ± 1720 kJ/m3 versus 5854 ± 2900 kJ/m3, mean difference 2232 [95% CI 70 to 4394]; p = 0.009) of samples irradiated at a higher temperature range (-40°C to 0°C) were lower than in those irradiated at deep-freezing temperatures (below -40°C). The mean 0.2% offset yield stress (73 ± 28 MPa versus 109 ± 38 MPa, mean difference 36 [95% CI 11 to 60]; p = 0.002) and ultimate compression stress (84 ± 27 MPa versus 128 ± 40 MPa, mean difference 44 [95% CI 17 to 69]; p < 0.001) of samples irradiated at a higher temperature range (-40°C to 0°C) were lower than the nonirradiated control group samples. The mean 0.2% offset yield stress (73 ± 28 MPa versus 101 ± 28 MPa, mean difference 28 [95% CI 3 to 52]; p = 0.02; effect size = 1.0 [95% CI 0.8 to 1.2]) of samples irradiated at higher temperature range (-40°C to 0°C) were no different with the numbers available to those irradiated at deep-freezing temperature. The mean toughness (3622 ± 1720 kJ/m3 versus 6231 ± 3410 kJ/m3, mean difference 2609 [95% CI 447 to 4771]; p = 0.02; effect size = 1.0 [95% CI 0.8 to 1.2]) of samples irradiated at higher temperature range (-40°C to 0°C) were no different with the numbers available to the non-irradiated control group samples. The mean 0.2% offset yield stress, ultimate compression stress, and toughness of samples irradiated in deep-freezing temperatures (below -40°C) were not different with the numbers available to the non-irradiated control group samples. The Young modulus was not different with the numbers available among the three groups.
CONCLUSION: In this study, maintenance of a deep-freezing temperature below -40°C, using dry ice as a cooling agent, consistently mitigated the adverse effects of irradiation on the monotonic-compression mechanical properties of human cortical bone tissue. Preserving the mechanical properties of a cortical allograft, when irradiated in a deep-freezing temperature, may have resulted from attenuation of the deleterious, indirect effects of gamma radiation on its collagen architecture in a frozen state. Immobilization of water molecules in this state prevents radiolysis and the subsequent generation of free radicals. This hypothesis was supported by an apparent loss of the protective effect when a range of higher freezing temperatures was used during irradiation.
CLINICAL RELEVANCE: Deep-freezing temperatures below -40°C during gamma irradiation may be a promising approach to better retain the native mechanical properties of cortical bone allografts. A further study of the effect of deep-freezing during gamma radiation sterilization on sterility and other important biomechanical properties of cortical bone (such as, tensile strength, fracture toughness, and fatigue) is needed to confirm these findings.
Materials and Methods: Twenty gel matrices were prepared with different durations of microwave irradiation, amounts of maize, and concentrations of sodium bicarbonate as suggested by Design Expert (DX®). The percentage drug release, the coefficient of variance (CV) in release, and the mean dissolution time (MDT) were the properties explored in the designed experimentation.
Results: Target responses were dependent on microwave irradiation time, cross-linker amount, and salt concentration. Classical and microwave heating did not demonstrate statistically significant difference in modifying the percentage of drug released from the matrices. However, the CVs of microwave-assisted formulations were lower than those of the gel matrices prepared via classical heating. Thus, microwave heating produced lesser variations in drug release. The optimized gel matrices demonstrated that the observed percentage of drug release, CV, and MDT were within the prediction interval generated by DX®. The release mechanism of the matrix formulations followed the Peppas-Korsmeyer anomalous transport model.
Conclusion: The DoE-supported microwave-assisted approach could be applied to optimize the critical factors of drug release with less variation.
METHODS: Participants were identified from the Department of Statistics Malaysia sampling frame. Surveys were carried out with individual households aged 18 years and older through self-administered questionnaires. Information was collected on demographics, household income, employment status, number of diseases, and HRQOL assessed using the EuroQol 5-Dimension 5-Level (EQ-5D-5L) tool.
RESULTS: Out of a total of 1899 participants, 620 (32.6%) were female and 328 (17.3%) were aged 60 years and above. The mean (SD) age was 45.2 (14.1) and mean (SD) household income was RM2124 (1356). Compared with younger individuals, older respondents were more likely to experience difficulties in mobility (32.1% vs 9.7%, p<0.001), self-care (11.6% vs 3.8%, p<0.001), usual activities (24.5% vs 9.1%, p<0.001), pain/discomfort (38.8% vs 16.5%, p<0.001) and anxiety/depression (21.4% vs 13.5%, p<0.001). The mean (SD) EQ-5D index scores were lower among older respondents, 0.89 (0.16) vs 0.95 (0.13), p = 0.001. After adjusting for covariates, age was a significant influencing factor (p = 0.001) for mobility (OR = 2.038, 95% CI:1.439-2.885), usual activities (OR = 1.957, 95% CI:1.353-2.832) and pain or discomfort (OR = 2.241, 95% CI:1.690-2.972).
CONCLUSION: Lower-income older adults had poorer HRQOL compared to their younger counterparts. This has important implications concerning intervention strategies that incorporate active ageing concepts on an individual and policy-making level to enhance the QOL and wellbeing, particularly among the older lower-income population.