Effects of Intermittent Femoral Nerve Injections of Bupivacaine, Levobupivacaine, and Ropivacaine on Mitochondrial Energy Metabolism and Intracellular Calcium Homeostasis in Rat Psoas Muscle

Background: Long-acting local anesthetics cause muscle damage. Moreover, long-acting local anesthetics act as uncoupler of oxidative phosphorylation in isolated mitochondria and enhance sarcoplasmic reticulum Ca2+ release. The aim of the study was to evaluate effects of perineural injections of local anesthetics on mitochondrial energetic metabolism and intracellular calcium homeostasis in vivo.

Methods: Femoral nerve block catheters were inserted in adult male Wistar rats. Rats were randomized and received seven injections (1 ml/kg) of bupivacaine, levobupivacaine, ropivacaine, or isotonic saline at 8-h intervals. Rats were killed 8 h after the last injection. Psoas muscle was quickly dissected from next to the femoral nerve. Local anesthetic concentrations in muscle were determined. Oxidative capacity was measured in saponin-skinned fibers. Oxygen consumption rates were measured, and mitochondrial adenosine triphosphate synthesis rate was determined. Enzymatic activities of mitochondrial respiratory chain complexes were evaluated. Local calcium release events (calcium sparks) were analyzed as well as sarcoplasmic reticulum calcium content in saponin-skinned fibers.

Results: Eight hours after the last injection, psoas muscle concentration of local anesthetics was less than 0.3 [mu]g/g tissue. Adenosine triphosphate synthesis and adenosine triphosphate-to-oxygen ratio were significantly decreased in the muscle of rats treated with local anesthetics. A global decrease (around 50%) in all of the enzyme activities of the respiratory chain was observed. Levobupivacaine increased the amplitude and frequency of the calcium sparks, whereas lower sarcoplasmic reticulum calcium content was shown.     

Radiation therapy in proliferative vitreoretinopathy

In a prospective study of the effect of postoperative radiation therapy for the prevention of reproliferation of membranes and recurrent proliferative vitreoretinopathy (PVR) two similar groups of patients with retinal detachment and PVR grade D1 to D3 in one eye were compared. Half the eyes (30) received a total dose of 3000 cGy after surgery; the other half remained untreated. After a followup of 6 months and 14 months or more (maximum 36 months) the anatomical and functional results of each group were compared. After 6 months in the unirradiated group 57% (17/30) remained attached and 43% (13/30) had detached again. In the irradiated group 63% (19/30) were attached and 37% (11/30) had detached. However, there was no statistically significant difference between the two groups (P=0.479, Fisher's Exact Test). After 14 months the number of cured and uncured eyes remained the same in the unirradiated group, while in four of the eyes in the irradiated group a later onset of reproliferation and detachment occurred (after 7, 8, 12 and 14 months, respectively). A final cure rate of 57% (17/30) was achieved in the unirradiated group and a 50% (15/30) cure rate in the irradiated group. Thus the failure rate was 43% (13/30) in the unirradiated group and 50% (15/30) in the irradiated group (P=0.473, Fisher's Exact Test). No side effects from the radiation were observed in any case and no radiation retinopathy occurred during an observation period of up to 3 years. The visual acuity of the cured treated and cured untreated eyes was similar in the two groups. From these results we conclude that immediate radiation treatment does not improve the long-term results and does not reduce the number of reoperations. In a considerable number of treated eyes the onset of reproliferation was delayed from 7 to 14 months, whereas in the untreated group reproliferation was always observed during the first 6 months. A combination of various antiproliferative and antiinflammatory therapies are needed to suppress recurrent PVR after succesful vitreoretinal surgery and to minimize the side effects of these treatments.Presented in part at the XVIIth Meeting of the Club Jules Gonin, 1–6 September 1990, Lausanne     

Per and neuropeptide expression in the rat suprachiasmatic nuclei: compartmentalization and differential cellular induction by light

Per1 and Per2, two clock genes rhythmically expressed in the suprachiasmatic nucleus (SCN), are implicated in the molecular mechanism of the circadian pacemaker and play a major role in its entrainment by light. To date, it is not known if every cell of the SCN, a heterogeneous structure in respect of neuropeptide content, expresses clock genes equally. The aim of this study was to identify, by single and double non-radioactive and/or radioactive hybridizations, the cell types (AVP, VIP and GRP) expressing Per1 or Per2 in the SCN of rats, (1) when Per are highly expressed during the daytime, and (2) after induction of Per expression by a light pulse at night. Our results indicate that, during the daytime, Per1 and Per2 genes are both mainly expressed in the AVP cells of the dorso-median part of the SCN, whereas only a few VIP cells in the ventral part of the SCN exhibit Per gene expression. In contrast, following a light pulse at night, there is differential induction of the two Per genes. Per1 expression essentially occurs in the ventro-lateral GRP cells, while Per2 expression is not restricted to the retinorecipient part of the SCN as it also occurs in AVP cells. Altogether, our results suggest that Per1 and Per2 are mainly expressed in AVP cells during the daytime and suggest that GRP cells play an important role in resetting of the clock by light.     

Biomonitoring of ciguatoxin exposure in mice using blood collection cards.

Ciguatera is a human food poisoning caused by consumption of tropical and subtropical fish that have, through their diet, accumulated ciguatoxins in their tissues. This study used laboratory mice to investigate the potential to apply blood collection cards to biomonitor ciguatoxin exposure. Quantitation by the neuroblastoma cytotoxicity assay of Caribbean ciguatoxin (C-CTX-1) spiked into mice blood was made with good precision and recovery. The blood collected from mice exposed to a sublethal dose of Caribbean ciguatoxic extract (0.59 ng/g C-CTX-1 equivalents) was analyzed and found to contain detectable toxin levels at least 12 h post-exposure. Calculated concentration varied from 0.25 ng/ml at 30 min post-exposure to 0.12 ng/ml at 12 h. A dose response mice exposure revealed a linear dose-dependent increase of ciguatoxin activity in mice blood, with more polar ciguatoxin congeners contributing to 89% of the total toxicity. Finally, the toxin measurement in mice blood exposed to toxic extracts from the Indian Ocean or from the Pacific Ocean showed that the blood collection card method could be extended to each of the three known ciguatoxin families (C-CTX, I-CTX and P-CTX). The low matrix effect of extracted dried-blood samples (used at 1:10 or 1:20 dilution) and the high sensitivity of the neuroblastoma assay (limit of detection 0.006 ng/ml C-CTX-1), determined that the blood collection card method is suitable to monitor ciguatoxin at sublethal doses in mice and opens the potential to be a useful procedure for fish screening, environmental risk assessment or clinical diagnosis of ciguatera fish poisoning in humans or marine mammals.     

A tailored lifestyle intervention to reduce the cardiovascular disease risk of individuals with Familial Hypercholesterolemia (FH): design of the PRO-FIT randomised controlled trial

Background  

Because of a high cardiovascular disease (CVD) risk in people with Familial Hypercholesterolemia (FH), early prevention of cardiovascular disease is important for health gain and cost reduction. This project focuses on the development and evaluation of an innovative intervention aiming to reduce CVD risk by promoting a healthy lifestyle among people with FH.     

Occupational exposure to textile dust and lung cancer risk: Results from the ICARE Study

Background

To investigate the association of lung cancer with occupational exposure to textile dust and specifically to cotton dust in the population‐based case‐control study ICARE.

Methods

Lifelong occupational history of 2926 cases and 3555 controls was collected using standardized questionnaires, with specific questions for textile dust exposure. Odds ratios (ORs) and 95% confidence intervals (CI) were estimated using unconditional logistic regression models controlling for confounding factors including smoking and asbestos exposure.

Results

An inverse association between textile dust exposure and lung cancer was found among workers exposed ≥5% of their work time (OR = 0.80, 95%CI = 0.58‐1.09), more pronounced for distant exposures (40+ years; up to a 56% reduced risk, statistically significant). The OR of lung cancer was significantly decreased among workers exposed to cotton fibers (OR = 0.70, 95%CI = 0.48‐0.97).

Conclusions

Our results provide some evidence of a decreased risk of lung cancer associated with exposure to textile dust, particularly cotton.

     

Expanding the boundaries of previously obtained informed consent in research: Views from participants in the Personalised Risk-based Mammascreening study

Introduction

Understanding participants' concerns and information needs regarding broadened consent is crucial to ensure transparency and participant autonomy. Our study qualitatively examined these issues in women participating in the Personalized RISk-based MAmmascreening study (PRISMA). The original PRISMA informed consent was project-specific (i.e., breast cancer research), limiting the scope of secondary research. We explored participants' needs for broadened consent to preserve informed decision-making while maximising the potential re-use of data.

Methods

Focus groups (FGs) were performed following a semistructured discussion guide. Two independent researchers analysed the data thematically using an inductive approach.

Findings

Twenty-three asymptomatic women and 13 women diagnosed with breast cancer were randomly divided into six FGs. Four superordinate themes were identified: (1) Normalization, (2) Attitude towards the pharmaceutical industry, (3) Privacy and (4) Knowledge. Our participants viewed data sharing as an important conduit for advancing medical science. Perceived integrity was more often attributed to noncommercial than commercial parties, with a marked mistrust towards the pharmaceutical industry. Most requested information needs related to data protection. Participants' ideal consent process would confer a range of options; for example, they would be able to choose with whom data can be shared, whether data will be de-identified or anonymous, the expiration date of their consent and how, if requested, general and personal study results would be disclosed.

Conclusion

Our participants expressed clear information needs and a strong desire to be actively engaged in future data sharing decisions. Given that many researchers collaborate with commercial parties, building public confidence in these institutions would be beneficial. Illustrative examples addressing privacy concerns and clarifying difficult terms would aid consent decision-making. Although our participants displayed great altruism in sharing their data and accepted that broad consent would ultimately facilitate future research, broad consent did not reflect their ideal situation. Dynamic consent may be an option but warrants further feasibility research.

Patient and Public Contribution

Women were recruited from the general breast cancer screening population. Their perceptions and information needs, as reported in this study, will not only inform broadened consent for PRISMA but ideally guide other consent templates and decisions regarding consent processes.     

Measuring patients' perceptions of patient-centered care: a systematic review of tools for family medicine

PURPOSE Patient-centered care is widely acknowledged as a core value in family medicine. In this systematic review, we aimed to identify and compare instruments, subscales, or items assessing patients’ perceptions of patient-centered care in family medicine.METHODS We conducted a systematic literature review using the MEDLINE, Embase, and Cochrane databases covering 1980 through April 2009, with a specific search strategy for each database. The search strategy was supplemented with searching by hand and expert suggestions. We looked for articles meeting all of the following criteria: (1) describing self-administered instruments measuring patient perceptions of patient-centered care; (2) reporting quantitative or psychometric results of development or validation; (3) being relevant to an ambulatory family medicine context. The quality of each article retained was assessed using a modified version of the Standards for Reporting of Diagnostic Accuracy. Instrument’ items were mapped to dimensions of a patient-centered care conceptual framework.RESULTS Of the 3,045 articles identified, 90 were examined in detail, and 26, covering 13 instruments, met our inclusion criteria. Two instruments (5 articles) were dedicated to patient-centered care: the Patient Perception of Patient-Centeredness and the Consultation Care Measure, and 11 instruments (21 articles) included relevant subscales or items.CONCLUSIONS The 2 instruments dedicated to patient-centered care address key dimensions but are visit-based, limiting their applicability for the study of care processes over time, such as chronic illness management. Relevant items from the 11 other instruments provide partial coverage of the concept, but these instruments were not designed to provide a specific assessment of patient-centered care.