Pyruvate dehydrogenase kinase/lactate axis: a therapeutic target for neovascular age-related macular degeneration identified by metabolomics.

Neovascular age-related macular degeneration (nAMD) is the leading cause of blindness in aging populations. Here, we applied metabolomics to human sera of patients with nAMD during an active (exudative) phase of the pathology and found higher lactate levels and a shift in the lipoprotein profile (increased VLDL-LDL/HDL ratio). Similar metabolomics changes were detected in the sera of mice subjected to laser-induced choroidal neovascularization (CNV). In this experimental model, we provide evidence for two sites of lactate production: first, a local one in the injured eye, and second a systemic site associated with the recruitment of bone marrow-derived inflammatory cells. Mechanistically, lactate promotes the angiogenic response and M2-like macrophage accumulation in the eyes. The therapeutic potential of our findings is demonstrated by the pharmacological control of lactate levels through pyruvate dehydrogenase kinase (PDK) inhibition by dichloroacetic acid (DCA). Mice treated with DCA exhibited normalized lactate levels and lipoprotein profiles, and inhibited CNV formation. Collectively, our findings implicate the key role of the PDK/lactate axis in AMD pathogenesis and reveal that the regulation of PDK activity has potential therapeutic value in this ocular disease. The results indicate that the lipoprotein profile is a traceable pattern that is worth considering for patient follow-up. KEY MESSAGES: Lactate and lipoprotein profile are associated with the active phase of AMD and CNV development. Lactate is a relevant and functional metabolite correlated with AMD progression. Modulating lactate through pyruvate dehydrogenase kinase led to a decrease of CNV progression. Pyruvate dehydrogenase kinase is a new therapeutic target for neovascular AMD.

Population health intervention research: what is the place for pilot studies?

BACKGROUND: An international workshop on population health intervention research (PHIR) was organized to foster exchanges between experts from different disciplines and different fields. AIMS: This paper aims to summarize the discussions around one of the issues addressed: the place or role of pilot studies in PHIR. Pilot studies are well-established in biomedical research, but the situation is more ambiguous for PHIR, in which a pilot study could refer to different purposes. METHODS: The workshop included formal presentations of participants and moderated discussions. An oral synthesis was carried out by a rapporteur to validate by expert consensus the key points of the discussion and the recommendations. All discussions have been recorded and fully transcribed. DISCUSSION: PHIR generally addresses complex interventions. Thus, numerous tasks may be required to inform the intervention and test different aspects of its design and implementation. While in clinical research the pilot study mainly concerns the preparation of the trial, in PHIR the pilot study focuses on the preparation of both the intervention and the trial. In particular, pilot studies in PHIR could be used for viability evaluation and theory development. RECOMMENDATIONS FROM THE WORKSHOP PARTICIPANTS: The following recommendations were generated by consensus from the workshop discussions: i) terms need to be clarified for PHIR; ii) reporting and publication should be standardized and transparency should be promoted; iii) the objectives and research questions should drive the methods used and be clearly stated; iv) a pilot study is generally needed for complex intervention evaluation and for research-designed programs; and v) for field-designed programs, it is important to integrate evaluability assessments as pilot studies . CONCLUSION: Pilot studies play an important role in intervention development and evaluation. In particular, they contribute to a better understanding of the mechanisms of intervention and the conditions of its applicability and transferability. Pilot studies could therefore facilitate evidence-based decisions about design and conduct of main studies aimed to generate evidence to inform public health policy.

Minor salivary gland biopsy in diagnosing ocular sarcoidosis.

BACKGROUND: To ascertain the sensitivity, specificity, and positive and negative predictive value of minor salivary gland biopsy in subsets of patients with uveitis consistent with ocular sarcoidosis. METHOD: Minor salivary gland biopsies performed in 230 patients with uveitis of indeterminate origin but clinically compatible with ocular sarcoidosis were reviewed. The biopsy results were analysed together with clinical features of uveitis and with the results of other relevant examinations, such as serum levels of angiotensin-I-converting enzyme and lysozyme, tuberculin skin test, chest radiography or CT scan, pulmonary function tests and bronchoalveolar lavage. RESULTS: Only seven of the 230 patients with uveitis had sarcoid granulomas on the minor salivary gland biopsy. All seven of these patients had a granulomatous uveitis and a compatible chest x-ray with sarcoidosis. The profitability of minor salivary gland biopsy can be improved by limiting the procedure to patients having granulomatous uveitis and a compatible chest x-ray. In these conditions, the positivity rate of minor salivary gland biopsy increased from 3% to 24% without loss of sensitivity. CONCLUSION: Minor salivary gland biopsy is most useful for assessing the diagnosis of sarcoid uveitis in a second-line investigation for patients with granulomatous uveitis and a radiologic pattern compatible with sarcoidosis.

Bone marrow-derived mesenchymal cells and MMP13 contribute to experimental choroidal neovascularization.

In this study, we evaluate the potential involvement of collagenase-3 (MMP13), a matrix metalloproteinase (MMP) family member, in the exudative form of age-related macular degeneration characterized by a neovascularisation into the choroid. RT-PCR analysis revealed that human neovascular membranes issued from patients with AMD expressed high levels of Mmp13. The contribution of MMP13 in choroidal neovascularization (CNV) formation was explored by using a murine model of laser-induced CNV and applying it to wild-type mice (WT) and Mmp13-deficient mice (Mmp13 ( -/- ) mice). Angiogenic and inflammatory reactions were explored by immunohistochemistry. The implication of bone marrow (BM)-derived cells was determined by BM engraftment into irradiated mice and by injecting mesenchymal stem cells (MSC) isolated from WT BM. The deficiency of Mmp13 impaired CNV formation which was fully restored by WT BM engraftment and partially rescued by several injections of WT MSC. The present study sheds light on a novel function of MMP13 during BM-dependent choroidal vascularization and provides evidence for a role for MSC in the pathogenesis of CNV.

Frosted branch angiitis with undiagnosed Hodgkin lymphoma.

PURPOSE: To report the case of a patient with bilateral frosted branch angiitis and undiagnosed Hodgkin lymphoma. METHODS: Review of clinical history, laboratory findings, histology of supraclavicular lymph node biopsy, and follow-up. RESULTS: A 22-year-old man presented with a sudden, bilateral visual loss. Fundus examination and fluorescein angiography disclosed a bilateral frosted branch angiitis that was dramatically responsive to systemic corticosteroid therapy. Laboratory tests were unremarkable but radiologic studies showed extensive mediastinal and supraclavicular lymphadenopathy. A supraclavicular lymph node biopsy led to the diagnosis of nodular sclerosis Hodgkin lymphoma. CONCLUSIONS: The occurrence of frosted branch angiitis in combination with classical Hodgkin lymphoma, although possibly coincidental, raises the possibility of a paraneoplastic syndrome. Thus, we suggest that, for patients with frosted branch angiitis, Hodgkin lymphoma should be considered in the diagnostic workup.

Tumoral and choroidal vascularization: differential cellular mechanisms involving plasminogen activator inhibitor type I.

An adequate balance between serine proteases and their plasminogen activator inhibitor-1 (PAI-1) is critical for pathological angiogenesis. PAI-1 deficiency in mice is associated with impaired choroidal neovascularization (CNV) and tumoral angiogenesis. In the present work, we demonstrate unexpected differences in the contribution of bone marrow (BM)-derived cells in these two processes regulated by PAI-1. PAI-1(-/-) mice grafted with BM-derived from wild-type mice were able to support laser-induced CNV formation but not skin carcinoma vascularization. Engraftment of irradiated wild-type mice with PAI-1(-/-) BM prevented CNV formation, demonstrating the crucial role of PAI-1 delivered by BM-derived cells. In contrast, the transient infiltration of tumor transplants by local PAI-1-producing host cells rather than by BM cells was sufficient to rescue tumor growth and angiogenesis in PAI-1-deficient mice. These data identify PAI-1 as a molecular determinant of a local permissive soil for tumor angiogenesis. Altogether, the present study demonstrates that different cellular mechanisms contribute to PAI-1-regulated tumoral and CNV. PAI-1 contributes to BM-dependent choroidal vascularization and to BM-independent tumor growth and angiogenesis.

Wegener's granulomatosis and posterior ischemic optic neuropathy: Atypical associated conditions.

We report the atypical course of two patients with posterior ischemic optic neuropathy (PION) and Wegener's granulomatosis (WG). The first case suggests that the optic nerve could be the primary and unique localization of WG. The second case suggests retrobulbar neuritis as another manifestation of WG, secondary to the autoimmune diathesis underlying this disease.

The challenge of measuring quality of care at health centre level in Africa: the example of Tsholotsho health district in Matabeleland North, Zimbabwe.

This study is on the evaluation of quality of health care within first line health services in rural Zimbabwe. It took place between 2001 and 2002, and consisted of a cross-sectional survey designed to compare the quality of health care on offer at a newly created health centre with that provided by the district hospital's outpatient department. The hypothesis to be tested was that the health centre offered better quality of care. A comprehensive quality of care evaluation framework was designed. The concept of patient enablement was incorporated into the study's assessment of health care delivery outcomes. The results did not provide conclusive evidence that the care offered at the health centre was better than the care on offer at the hospital OPD. The reasons for these unexpected findings are discussed in depth. They are related to the limited understanding amongst local health workers of the organisational changes introduced by the District Health Executive (DHE), together with a (European) cultural bias in the quality of care model under test. An important lesson of this study is that the notion of enablement, notwithstanding the need to put into context the tools used to measure it, was considered by the DHE as relevant in the organisation and evaluation of health care.

Spontaneous recovery in phacolytic glaucoma.

We report a case of phacolytic glaucoma in which spontaneous absorption of the hypermature lens allowed a patient who refused surgery to recover a normal pressure and satisfactory visual acuity.

Measuring unmet obstetric need at district level: how an epidemiological tool can affect health service organization and delivery.

A national retrospective survey on the unmet need for major obstetric surgery using the Unmet Obstetric Need Approach was carried out in Mali in 1999. In Koutiala, the district health team decided to carry on the monitoring of the met need for several years in order to assess their progress over time. The first prospective study, for 1999, estimated that more than 100 women in need of obstetric care never reached the hospital and probably died as a consequence. This surprising result shocked the district health team and the resulting increased awareness of service deficits triggered operational measures to tackle the problem. The Unmet Obstetric Need study in Koutiala district was implemented without financial support and only limited external technical back-up. The appropriation of the study by the district team for solving local problems of access to obstetric care may have contributed to the success of the experience. Used as a health service management tool, the study and its results started a dialogue between the hospital staff and both health centre staff and community representatives. This had not only the effect of triggering consideration of coverage, but also of quality of obstetric care.

Pilfering for survival: how health workers use access to drugs as a coping strategy.

BACKGROUND: Coping strategies have, in some countries, become so prevalent that it has been widely assumed that the very notion of civil services ethos has completely - and possibly irreversibly - disappeared. This paper describes the importance and the nature of pilfering of drugs by health staff in Mozambique and Cape Verde, as perceived by health professionals from these countries. Their opinions provide pointers as to how to tackle these problems. METHODS: This study is based on a self-administered questionnaire addressed to a convenience sample of health workers in Mozambique and in Cape Verde. RESULTS: The study confirms that misuse of access to pharmaceuticals has become a key element in the coping strategies health personnel develop to deal with difficult living conditions. Different professional groups (mis)use their privileged access in different ways, but doctors diversify most. The study identifies the reasons given for misusing access to drugs, shows how the problem is perceived by the health workers, and discusses the implications for finding solutions to the problem.Our findings reflect, from the health workers themselves, a conflict between their self image of what it means to be an honest civil servant who wants to do a decent job, and the brute facts of life that make them betray that image. The manifest unease that this provokes is an important observation as such. CONCLUSION: Our findings suggest that, even in the difficult circumstances observed in many countries, behaviours that depart from traditional civil servant deontology have not been interiorised as a norm. This ambiguity indicates that interventions to mitigate the erosion of proper conduct would be welcome. The time to act is now, before small-scale individual coping grows into large-scale, well-organized crime.

An unusual case of death: suffocation caused by leaves of common ivy (Hedera helix). Detection of hederacoside C, alpha-hederin, and hederagenin by LC-EI/MS-MS.

We report one fatal case of asphyxia caused by leaves of common ivy. Macroscopic examination of the corpse during the autopsy disclosed an incredible quantity of leaves of Hedera helix in the mouth and throat of the decedent. In order to rule out the possibility of poisoning by the toxic saponins contained in the plant, we have developed an efficient LC-EI/MS-MS assay of hederacoside C, alppha-hederin, and hederagenin in biological fluids and plant material. Sample cleanup involved solid-phase extraction of the toxins on C18 cartridges followed by LC analysis under reversed-phase conditions in the gradient elution mode. Solute identification was performed using full scan MS-MS spectrum of the analytes. Oleandrine was used as internal standard. Under these conditions, saponins in powdered dried leaves of Hedera helix were measured at a concentration of 21.83 mg/g for hederacoside C, 0.41 mg/g for alpha-hederin and 0.02 mg/g for hederagenin. No toxin was detected in cardiac blood, femoral blood, or urine of the deceased, but hederacoside C was quantitated at 857 ng/mL in the gastric juice. These findings led us to conclude that the man committed suicide and that the death was caused by suffocation by leaves of common ivy.