Healthcare needs, experiences and treatment burden in primary care patients with multimorbidity: An evaluation of process of care from patients' perspectives.

BACKGROUND: Patients with multimorbidity often experience treatment burden as a result of fragmented, specialist-driven healthcare. The 'family doctor team' is an emerging service model in China to address the increasing need for high-quality routine primary care. OBJECTIVE: This study aimed to explore the extent to which treatment burden was associated with healthcare needs and patients' experiences. METHODS: Multisite surveys were conducted in primary care facilities in Guangdong province, southern China. Interviewer-administered questionnaires were used to collect data from patients (N = 2160) who had ≥2 clinically diagnosed long-term conditions (multimorbidity) and had ≥1 clinical encounter in the past 12 months since enrolment registration with the family doctor team. Patients' experiences and treatment burden were measured using a previously validated Chinese version of the Primary Care Assessment Tool (PCAT) and the Treatment Burden Questionnaire, respectively. RESULTS: The mean age of the patients was 61.4 years, and slightly over half were females. Patients who had a family doctor team as the primary source of care reported significantly higher PCAT scores (mean difference 7.2 points, p < .001) and lower treatment burden scores (mean difference -6.4 points, p < .001) when compared to those who often bypassed primary care. Greater healthcare needs were significantly correlated with increased treatment burden (ß-coefficient 1.965, p < .001), whilst better patients' experiences were associated with lower treatment burden (ß-coefficient -0.252, p < .001) after adjusting for confounders. CONCLUSION: The inverse association between patients' experiences and treatment burden supports the importance of primary care in managing patients with multimorbidity. PATIENT CONTRIBUTION: Primary care service users were involved in the instrument development and data collection.

Influence of alkylthio and arylthio derivatives of tert-butylquinone on the induction of DNA damage in a human hepatocellular carcinoma cell line (HepG2).

The aim of this study was to investigate the effects of tert-butylquinone (TBQ) and its alkylthio and arylthio derivatives on DNA in vitro, using acellular and cellular test systems. Direct interaction with DNA was studied using the plasmid pUC19. Cytotoxic (MTS assay) and genotoxic (comet assay and γH2AX focus assays) effects, and their influence on the cell cycle were studied in the HepG2 cell line. Our results show that TBQ and its derivatives did not directly interact with DNA. The strongest cytotoxic effect on the HepG2 cells was observed for the derivative 2-tert-butyl-5,6-(ethylenedithio)-1,4-benzoquinone (IC50 64.68 and 55.64 µM at 24-h and 48-h treatment, respectively). The tested derivatives did not significantly influence the cell cycle distribution in the exposed cellular populations. However, all derivatives showed a genotoxic activity stronger than that of TBQ in the comet assay, with 2-tert-butyl-5,6-(ethylenedithio)-1,4-benzoquinone producing the strongest effect. The same derivative also induced DNA double-strand breaks in the γH2AX focus assay.

Oxidative Conversion Mediates Antiproliferative Effects of tert-Butylhydroquinone: Structure and Activity Relationship Study.

Previous studies have shown that tert-butylhydroquinone (TBHQ), a widely used food antioxidant, has cytotoxic effects at high doses; however, the underlying mechanisms are not well understood. Here, we found that the effects of TBHQ on cell proliferation, cell cycle progression, and apoptosis are mainly mediated by its oxidative conversion to a quinone metabolite tert-butylquinone (TBQ). Co-addition of cupric ion (Cu(2+)) caused accelerated oxidative conversion of TBHQ to TBQ and enhanced the biological activities of TBHQ on cell proliferation, cell cycle progression, and apoptosis in MC38 colon cancer cells. In contrast, co-addition of ethylenediaminetetraacetic acid (EDTA) suppressed TBHQ oxidation and inhibited the biological activities of TBHQ in MC38 cells. For example, after 24 h of treatment in basal medium, low-dose TBHQ (1.88-7.5 µM) had little effect on MC38 cell proliferation, while co-addition of 50 µM Cu(2+) caused 30-70% inhibition of cell proliferation; in contrast, treatment with high-dose TBHQ (15 µM) inhibited 50 ± 4% MC38 proliferation, which was abolished by co-addition of 50 µM EDTA. We further showed that TBQ had more potent actions on cell proliferation and associated cellular responses than TBHQ, supporting a critical role of TBQ formation in the biological activities of TBHQ. Finally, a structure and activity relationship study showed that the fast-oxidized para-hydroquinones had potent antiproliferative effects in MC38 cells, while the slow-oxidized para-hydroquinones had weak or little biological activities. Together, these results suggest that the biological activities of TBHQ and other para-hydroquinones are mainly mediated by their oxidative metabolism to generate more biologically active quinone metabolites.

The effect of 2,5-di-(tert-butyl)-1,4-benzohydroquinone (TBQ) on intracellular Ca2+ handling in rat ventricular myocytes.

2,5-Di-(tert-butyl)-1,4-benzohydroquinone (TBQ) is a reversible inhibitor of SERCA, potentially making it a useful tool to study the effects of SERCA inhibition in cardiac cells. However, it is unknown if TBQ also has effects on other components of ventricular Ca handling. The aim of these experiments was to characterise the effects of TBQ on Ca handling in rat ventricular myocytes and assess its suitability as a specific inhibitor of SERCA. This was achieved by voltage clamp via perforated patch and [Ca(2+)]i measurement using Fluo-3 AM. TBQ produced a fully reversible, concentration dependent decrease in the rate of systolic Ca decay. 10µM TBQ decreased the amplitude of the systolic Ca transient by 48±5% and the rate of decay by 54±6%. SR Ca content was also reduced by 62±4%. However, 10µM TBQ also decreased the peak L-type Ca current by 23±7%. At higher concentrations (100µM), TBQ also activated an outward current with a current-voltage relationship consistent with a potassium current. This outward current was abolished by Glibenclamide (100µM). These data show that TBQ can be used to reversibly inhibit SERCA. However, at concentrations that decrease SERCA activity, TBQ also decreases the L-type Ca current and (at higher concentrations) activates an outward current which appears to be an ATP dependent potassium current. We conclude that TBQ cannot be used as a specific inhibitor of SERCA in rat ventricular myocytes.