Evaluation of the visual function of patients with locked-in syndrome: Report of 13 cases

Although visual function is thought to be preserved in patients with locked-in syndrome (LIS), enabling them to communicate through vertical or lateral eye movements or blinking of the upper eyelid, nothing is known about the actual visual function of patients with LIS. The goal of this study is to evaluate the visual function of patients with LIS which may enable better evaluation of the state of consciousness of these patients. Patients with LIS seen in a single neurovascular unit of a tertiary center between 1997 and 2013 were retrospectively reviewed. Each patient had a specialized neuro-ophthalmological evaluation under optimal environmental conditions (light, contrast, examination distance, head position, best ergonomic adaptation, and establishment of a means of communication with help from the patient's friends/family). Visual acuity, extraocular eye movements, confrontational visual field, slit lamp and fundus examination were performed. Thirteen patients (6M/7F) were included in this study. Mean visual acuity was 20/60. Oculomotor examination was abnormal in 77%. Forty-six percent of patients presented binocular diplopia mainly related to a VIth nerve palsy. One patient presented complete ophthalmoplegia. Forty-six percent of patients had nystagmus responsible for oscillopsia (oculopalatal tremor). An abnormal visual field was observed in 17% of patients, and abnormal pupillary light response leading to photophobia was present in 22% of patients. Keratitis or dry eye syndrome was present in most patients and was a major cause of pain and visual impairment. Our results suggest that the visual function is impaired in all patients with LIS. This impairment is multifactorial including mostly binocular diplopia or oscillopsia but also refractive errors, dry eye syndrome, keratitis or visual field defect. This altered visual function may alter the ability of the patient to interact with his environment and lead to underestimation of their state of consciousness. An ophthalmologic evaluation would allow for improvement of these patients' comfort, their ability to communicate, and the assessment of their state of consciousness.

[Comparison of early management of central retinal vein occlusion with ranibizumab versus hemodilution]

PURPOSE

This study was designed to evaluate and compare the efficacy of early treatment of CRVO with either hemodilution by erythrocytopheresis or intravitreal (IVT) ranibizumab, or both.

MATERIAL AND METHODS

A multicentric prospective randomized study including patients with CRVO for less than 1 month was designed. Patients were randomized into 3 treatment groups: hemodilution (HD group), 3 monthly intravitreal injections of ranibizumab followed by PRN treatment (IVT group), or combined treatment (IVT+HD group). A monthly evaluation during a 6-month follow-up included best-corrected visual acuity (BCVA) and macular thickness measurements with OCT. Fluorescein angiography was performed at baseline, month 2 and month 6. Local and systemic tolerability of the different treatments were also compared.

RESULTS

Forty-four CRVO patients were included between February 2010 and June 2013: 20 in the IVT group, 13 in the HD group and 11 in the HD+IVT group. The mean duration of CRVO at baseline was 10 days and 16 days at the time of treatment without any significant difference between groups. Retinal ischemia was present at baseline in 40% of eyes in each group. After a 6-month follow-up, no difference between the 3 groups was observed in BCVA (10.5 ETDRS letters, 14.6 and 14.1 in the IVT group, HD group and IVT+HD group respectively, P=0.726) or in macular thickness (398 μ, 440 μ and 379 μ respectively, P=0.465). The time until treatment from CRVO onset, ranging from 1 to 35 days, was not correlated to final outcomes. No significant difference in the mean number of IVT (3.2 in the IVT+HD group vs 3.7 in the IVT group) was observed at 6 months.

CONCLUSION

No difference in BCVA nor in macular thickness was seen at M6 between the study groups. The duration of CRVO at the time of the initiation of the treatment was not correlated to better visual outcomes. Therefore, etiologic treatment with HD can still be proposed as a first-line treatment in young patients, which allows delaying or avoiding the IVT treatment and its potential side effects. Anti-VEGF IVT still remains an effective option in every case and can be started one month after the beginning of the CRVO.

Statins and fibrates for preventing melanoma

BACKGROUND

Effective treatment for advanced melanoma is lacking. While no drug therapy currently exists for prevention of melanoma, in vitro, case-control, and animal model evidence suggest that lipid-lowering medications, commonly taken for high cholesterol, might prevent melanoma.

OBJECTIVES

To assess the effects of statin or fibrate lipid-lowering medications on melanoma outcomes.

SEARCH STRATEGY

We searched the Cochrane Skin Group Specialised Register (February 2003), CENTRAL (The Cochrane Library Issue 1, 2005), MEDLINE (to March 2003), EMBASE (to September 2003), CANCERLIT (to October 2002), Web of Science (to May 2003), and reference lists of articles. We approached study investigators and pharmaceutical companies for additional information (published or unpublished studies).

SELECTION CRITERIA

Trials involving random allocation of study participants, where experimental groups used statins or fibrates and participants were enrolled for at least four years of therapy.

DATA COLLECTION AND ANALYSIS

Three authors screened 109 abstracts of articles with titles of possible relevance. We then thoroughly examined the full text of 72 potentially relevant articles. We requested unpublished melanoma outcomes data from the corresponding author of each qualifying trial.

MAIN RESULTS

We identified 16 qualifying randomised controlled trials (RCTs) (seven statin, nine fibrate). Thirteen of these trials (involving 62,197 participants) provided data on incident melanomas (six statin, seven fibrate). A total of 66 melanomas were reported in groups receiving the experimental drug and 86 in groups receiving placebo or other control therapies. For statin trials this translated to an odds ratio of 0.90 (95% confidence interval 0.56 to 1.44) and for fibrate trials an odds ratio of 0.58 (95% confidence interval 0.19 to 1.82). Subgroup analyses failed to show statistically significant differences in melanoma outcomes by gender, melanoma occurrence after two years of participation in trial, stage or histology, or trial funding. Subgroup analysis by type of fibrate or statin also failed to show statistically significant differences, except for the statin subgroup analysis which showed reduced melanoma incidence for lovastatin, based on one trial only (odds ratio 0.52, 95% confidence interval 0.27 to 0.99).

AUTHORS' CONCLUSIONS

The melanoma outcomes data collected in this review of RCTs of statins and fibrates does not exclude the possibility that these drugs prevent melanoma. There was a 10% and 42% reduction for participants on statins and fibrates, respectively, however these results were not statistically significant. Until further evidence is established, limiting exposure to ultraviolet radiation remains the most effective way to reduce the risk of melanoma.

Bioavailability of US commercial magnesium preparations

Magnesium deficiency is seen with some frequency in the outpatient setting and requires oral repletion or maintenance therapy. The purpose of this study was to measure the bioavailability of four commercially-available preparations of magnesium, and to test the claim that organic salts are more easily absorbed. Bioavailability was measured as the increment of urinary maginesium excretion in normal volunteers given approximately 21 mEq/day of the test preparations. Results indicated relatively poor bioavailability of magnesium oxide (fractional absorption 4 per cent) but significantly higher and equivalent bioavailability of magnesium chloride, magnesium lactate and magnesium aspartate. We conclude that there is relatively poor bioavailability of magnesium oxide, but greater and equivalent bioavailability of magnesium chloride, lactate, and aspartate. Inorganic magnesium salts, depending on the preparation, may have bioavailability equivalent to organic magnesium salts.

Alcoholysis catalyzed by Candida antarctica lipase B in a gas/solid system obeys a Ping Pong Bi Bi mechanism with competitive inhibition by the alcohol substrate and water

The kinetics of alcoholysis of methyl propionate and n-propanol catalyzed by Candida antarctica lipase B supported onto silanized Chromosorb P was studied in a continuous solid/gas reactor. In this system the solid phase is composed of a packed enzymatic sample and is percolated by nitrogen as carrier gas, which simultaneously carries substrates to the enzyme while removing reaction products. In this reactor the thermodynamic activity of substrates and effectors can be perfectly adjusted allowing kinetic studies to be performed under different operating conditions. The kinetics obtained for alcoholysis were suggested to fit a Ping Pong Bi Bi mechanism with dead-end inhibition by the alcohol. The values of all apparent kinetic parameters were calculated and the apparent dissociation constant of enzyme for gaseous ester was found very low compared with the one obtained for liquid ester in organic medium, certainly due to the more efficient diffusion in the gaseous phase. The effect of water thermodynamic activity was also investigated. Water was found to act as a competitive inhibitor, with a higher inhibition constant than n-propanol. Thus alcoholysis of gaseous methyl propionate and n-propanol catalyzed by C. antarctica lipase B was found to obey the same kinetic mechanism as in other non-conventional media such as organic liquid media and supercritical carbon dioxide, but with much higher affinity for the substrates.

Isolation, purification and partial amino acid sequence of a highly hydrophobic new microcin named microcin L produced by Escherichia coli

We report here the production, by an Escherichia coli strain, of two microcins, microcin J25 and a new one that we designated microcin L. The active peptides were separated by solid phase extraction on C(18) cartridges. Microcin L was then purified to homogeneity by cationic-exchange high-performance liquid chromatography. Its molecular mass, determined by mass spectrometry, is 8899 Da. The amino acid composition and the sequence of the first 40 N-terminal residues indicate that microcin L is a hydrophobic peptide, which exhibits high homology to gassericin and lactacin F which both belong to the class II bacteriocins.