Vitamin D status modulates mitochondrial oxidative capacities in skeletal muscle: role in sarcopenia.

Skeletal muscle mitochondrial function is the biggest component of whole-body energy output. Mitochondrial energy production during exercise is impaired in vitamin D-deficient subjects. In cultured myotubes, loss of vitamin D receptor (VDR) function decreases mitochondrial respiration rate and ATP production from oxidative phosphorylation. We aimed to examine the effects of vitamin D deficiency and supplementation on whole-body energy expenditure and muscle mitochondrial function in old rats, old mice, and human subjects. To gain further insight into the mechanisms involved, we used C2C12 and human muscle cells and transgenic mice with muscle-specific VDR tamoxifen-inducible deficiency. We observed that in vivo and in vitro vitamin D fluctuations changed mitochondrial biogenesis and oxidative activity in skeletal muscle. Vitamin D supplementation initiated in older people improved muscle mass and strength. We hypothesize that vitamin D supplementation is likely to help prevent not only sarcopenia but also sarcopenic obesity in vitamin D-deficient subjects.

Intra-Ocular Pressure Response to Dexamethasone Implant Injections in Patients with a History of Filtering Surgery: The TRABEX Study.

Patients with both macular edemas, of various etiologies such as diabetes and glaucoma, may suffer serious loss of vision if either disease goes untreated. Where no effective alternative therapies are available, dexamethasone implant (DEX-I) injections may be the only choice of treatment, despite the risk of a possible increase in intraocular pressure (IOP) when using steroids. Although many studies have reported on IOP evolution in eyes treated with DEX-I, little is known specifically about eyes with a history of filtering surgery. The aim of this observational series was to evaluate the IOP response following DEX-I injection in eyes presenting conventional filtering surgeries or microinvasive glaucoma surgeries (MIGS). Twenty-five eyes were included in this study. A total of 64% of the eyes did not experience OHT during follow-up. Additional IOP-lowering therapy was needed for 32% of eyes, and 20% of eyes (all showing bleb fibrosis) required further filtering surgery: 50% of eyes in the MIGS group and 10.5% of eyes in the conventional filtering surgery group. A significant positive correlation was found between IOP at baseline and the maximum IOP throughout follow-ups after DEX-I (r = 0.45, p = 0.02). In conclusion, if DEX-I is used when there are no alternative therapies for treating macular edema, IOP in eyes with a history of filtering surgery is generally manageable. Those eyes which previously underwent conventional therapy with effective blebs obtained better IOP control after DEX-I injections and mostly did not require any additional IOP-lowering therapy or surgery.

Unexpected amaurosis occurring after peribulbar anesthesia: Exploring the causes in two cases.

Peribulbar anesthesia (PB) is known to be safer than retrobulbar (RB) anesthesia. To our knowledge, no amaurosis has been described after PB. We report here the cases of two patients who underwent PB before membrane peeling. The injections were administered with a 25-gauge, 22-mm bevel disposable needle. The anesthetic used was ropivacaine 1% with a volume of 8 ml and 75 µg of clonidine as an adjuvant (7.5 µg/ml). Given that complete akinesia was not achieved, a second injection of 2 ml was administered in the supero-medial injection site. Thirty minutes after the PB, the first patient experienced amaurosis with no light perception (LP). The ophthalmic examination was normal. Visual acuity recovered after 1 day. Regarding the second patient, the loss of VA was observed 20 min after the PB. IOP was 20 mmHg. The anterior segment and fundus exam were normal. Rubin found the PB technique to be as effective and safer than RB injection, as the needles are not supposed to enter the RB space and Davis and Mandel found no amaurosis after PB. PB is administered via the extraconal injection of an anesthetic agent. These amaurosis might be explained by the fact that some anesthetic may have penetrated the RB space. In cases where two PB injections are administered, the anatomy is expected to change due to the volume effect of the first injection. The second injection is higher risk as it is administered closer to the optic nerve.

Fast digestive, leucine-rich, soluble milk proteins improve muscle protein anabolism, and mitochondrial function in undernourished old rats.

SCOPE: One strategy to manage malnutrition in older patients is to increase protein and energy intake. Here, we evaluate the influence of protein quality during refeeding on improvement in muscle protein and energy metabolism. METHODS AND RESULTS: Twenty-month-old male rats (n = 40) were fed 50% of their spontaneous intake for 12 weeks to induce malnutrition, then refed ad libitum with a standard diet enriched with casein or soluble milk proteins (22%) for 4 weeks. A 13C-valine was infused to measure muscle protein synthesis and expression of MuRF1, and MAFbx was measured to evaluate muscle proteolysis. mTOR pathway activation and mitochondrial function were assessed in muscle. Malnutrition was associated with a decrease in body weight, fat mass, and lean mass, particularly muscle mass. Malnutrition decreased muscle mTOR pathway activation and protein FSR associated with increased MuRF1 mRNA levels, and decreased mitochondrial function. The refeeding period partially restored fat mass and lean mass. Unlike the casein diet, the soluble milk protein diet improved muscle protein metabolism and mitochondrial function in old malnourished rats. CONCLUSIONS: These results suggest that providing better-quality proteins during refeeding may improve efficacy of renutrition in malnourished older patients.

Vitamin D supplementation restores the blunted muscle protein synthesis response in deficient old rats through an impact on ectopic fat deposition.

We investigated the impact of vitamin D deficiency and repletion on muscle anabolism in old rats. Animals were fed a control (1 IU vitamin D3/g, ctrl, n=20) or a vitamin D-depleted diet (VDD; 0 IU, n=30) for 6 months. A subset was thereafter sacrificed in the control (ctrl6) and depleted groups (VDD6). Remaining control animals were kept for 3 additional months on the same diet (ctrl9), while a part of VDD rats continued on a depleted diet (VDD9) and another part was supplemented with vitamin D (5 IU, VDS9). The ctr16 and VDD6 rats and the ctr19, VDD9 and VDS9 rats were 21 and 24 months old, respectively. Vitamin D status, body weight and composition, muscle strength, weight and lipid content were evaluated. Muscle protein synthesis rate (fractional synthesis rate; FSR) and the activation of controlling pathways were measured. VDD reduced plasma 25(OH)-vitamin D, reaching deficiency (<25 nM), while 25(OH)-vitamin D increased to 118 nM in the VDS group (P<.0001). VDD animals gained weight (P<.05) with no corresponding changes in lean mass or muscle strength. Weight gain was associated with an increase in fat mass (+63%, P<.05), intramyocellular lipids (+75%, P<.05) and a trend toward a decreased plantaris weight (-19%, P=.12). Muscle FSR decreased by 40% in the VDD group (P<.001), but was restored by vitamin D supplementation (+70%, P<.0001). Such changes were linked to an over-phosphorylation of eIF2α. In conclusion, vitamin D deficiency in old rats increases adiposity and leads to reduced muscle protein synthesis through activation of eIF2α. These disorders are restored by vitamin D supplementation.

Long-term dietary supplementation with cystathionine improves tissue glutathione in ageing rats.

BACKGROUND: Ageing is associated with decrease in tissue glutathione that can be reduced by food fortification with the amino acid cysteine. However, cysteine is not stable in solution and generates bad taste. Cystathionine, the direct precursor of cysteine, could be a valuable alternative. AIMS: This study aimed to determine whether long-term dietary supplementation with cystathionine induces an increase in glutathione pools. METHODS: Aged rats (20.5-month-old) were fed ad libitum during 29 weeks with either a cystathionine-supplemented diet (7.3 g/kg, n = 90 rats) or a control iso-nitrogenous alanine-supplemented diet (2.9 g/kg, n = 90 rats). RESULTS: Cystathionine was detected in the plasma of the cystathionine-supplemented rats but not in the control alanine-supplemented rats. Cystathionine increased glutathione concentrations in liver, small intestine and gastrocnemius muscle (P < 0.03). No adverse effect was observed. CONCLUSION: Cystathionine supplementation being able to increase moderately glutathione in healthy old rats could be considered as a candidate for nutritional supports aiming to revert the stronger glutathione depletions occurring in unhealthy elderly.

Bee pollen improves muscle protein and energy metabolism in malnourished old rats through interfering with the Mtor signaling pathway and mitochondrial activity.

Although the management of malnutrition is a priority in older people, this population shows a resistance to refeeding. Fresh bee pollen contains nutritional substances of interest for malnourished people. The aim was to evaluate the effect of fresh bee pollen supplementation on refeeding efficiency in old malnourished rats. Male 22-month-old Wistar rats were undernourished by reducing food intake for 12 weeks. The animals were then renourished for three weeks with the same diet supplemented with 0%, 5% or 10% of fresh monofloral bee pollen. Due to changes in both lean mass and fat mass, body weight decreased during malnutrition and increased after refeeding with no between-group differences (p < 0.0001). Rats refed with the fresh bee pollen-enriched diets showed a significant increase in muscle mass compared to restricted rats (p < 0.05). The malnutrition period reduced the muscle protein synthesis rate and mTOR/p70S6kinase/4eBP1 activation, and only the 10%-pollen diet was able to restore these parameters. Mitochondrial activity was depressed with food restriction and was only improved by refeeding with the fresh bee pollen-containing diets. In conclusion, refeeding diets that contain fresh monofloral bee pollen improve muscle mass and metabolism in old, undernourished rats.

Long-term cysteine fortification impacts cysteine/glutathione homeostasis and food intake in ageing rats.

PURPOSE: Healthy ageing is associated with higher levels of glutathione. The study aimed to determine whether long-term dietary fortification with cysteine increases cysteine and glutathione pools, thus alleviating age-associated low-grade inflammation and resulting in global physiological benefits. METHODS: The effect of a 14-week dietary fortification with cysteine was studied in non-inflamed (NI, healthy at baseline) and in spontaneously age-related low-grade inflamed (LGI, prefrail at baseline) 21-month-old rats. Fifty-seven NI rats and 14 LGI rats received cysteine-supplemented diet (4.0 g/kg of free cysteine added to the standard diet containing 2.8 g/kg cysteine). Fifty-six NI rats and 16 LGI rats received a control alanine-supplemented diet. RESULTS: Cysteine fortification in NI rats increased free cysteine (P < 0.0001) and glutathione (P < 0.03) in the liver and the small intestine. In LGI rats, cysteine fortification increased total non-protein cysteine (P < 0.0007) and free cysteine (P < 0.03) in plasma, and free cysteine (P < 0.02) and glutathione (P < 0.01) in liver. Food intake decreased over time in alanine-fed rats (r² = 0.73, P = 0.0002), whereas it was constant in cysteine-fed rats (r² = 0.02, P = 0.68). Cysteine fortification did not affect inflammatory markers, mortality, body weight loss, or tissue masses. CONCLUSION: Doubling the dietary intake of cysteine in old rats increased cysteine and glutathione pools in selected tissues. Additionally, it alleviated the age-related decline in food intake. Further validation of these effects in the elderly population suffering from age-related anorexia would suggest a useful therapeutic approach to the problem.

Nutritional, lifestyle and environmental factors in ocular hypertension and primary open-angle glaucoma: an exploratory case-control study.

PURPOSE: To evaluate known and potential risk factors, including nutritional, lifestyle and environmental factors, differentiating patients with high-tension primary open-angle glaucoma (POAG) from control subjects with ocular hypertension (OHT). METHODS: In 2006-2007, 111 French ophthalmologists prospectively enrolled 339 cases of POAG and 339 age-matched controls with OHT. After a clinical examination with assessment of ocular risk factors, the ophthalmologist filled, during face-to-face interview, a detailed questionnaire developed by nutritionists and epidemiologist on lifestyle and environmental risk factors, including socio-demographic variables, dietary habits related to omega-3 fatty acids intake, smoking and alcohol drinking and professional exposure to pesticides and other chemicals. Associations of POAG with risk factors were estimated using conditional logistic regression, with adjustment for age, gender and duration of disease. RESULTS: In the final multivariate model, by comparison with OHT, POAG was significantly associated with more frequent use of pesticides during the professional life [OR = 2.65, 95% confidence interval (CI): 1.04-6.78, p = 0.04] and with low consumption of fatty fish (OR = 2.14, 95% CI: 1.10-4.17, p = 0.02) and walnuts (OR = 2.02, 95% CI: 1.18-3.47, p = 0.01). POAG was also associated with higher frequency of heavy smoking (40 pack-years or more, OR = 3.93, 95% CI: 1.12-13.80, p = 0.03) but not with moderate (20-40 pack-years) and light smoking (<20 pack-years). CONCLUSIONS: These exploratory observations suggest a protective effect of omega-3 fatty acids and a deleterious effect of heavy smoking and professional exposure to pesticides in POAG. This will need to be confirmed in future studies.

Gastric electrical stimulation in medically refractory nausea and vomiting.

INTRODUCTION: High-frequency gastric electrical stimulation is a new therapeutic option to improve refractory nausea and vomiting, in gastroparetic patients. Its effects on gastric emptying are, however, inconstant and limited. Therefore, we have hypothesized that high-frequency gastric electrical stimulation could be also effective in patients suffering from refractory vomiting and nausea with normal gastric emptying, and we have compared the symptomatic efficacy of high-frequency gastric electrical stimulation between patients with delayed and normal gastric emptying. PATIENTS AND METHODS: Fifteen patients with chronic, severe and medically resistant nausea and vomiting were included in the study. Gastric emptying was delayed in eight patients (Group 1) and normal in seven patients (Group 2). At inclusion and at 6 months after the start of the stimulation, symptoms (nausea and vomiting, bloating, regurgitations, abdominal pain and appetite) and quality of life were prospectively evaluated using the Gastrointestinal Quality of Life Index score whereas gastric emptying was assessed by scintigraphy and/or octanoic acid breath test. RESULTS: Age, sex, symptoms and quality of life were not different at baseline between the two groups. At 6 months, Gastrointestinal Quality of Life Index and nausea/vomiting scores had significantly improved in both groups. Other symptoms (bloating, regurgitations, abdominal pain and appetite) had improved at 6 months in Group 1 but not in Group 2. Six months after the start of stimulation, gastric emptying was normal in 4/8 Group 1 patients and 5/7 Group 2 patients but was not significantly different from that calculated before the implantation of the stimulator. CONCLUSION: Our results suggest that high-frequency gastric electrical stimulation could be an effective therapy for treating chronic, severe vomiting and nausea whether gastric emptying is delayed or not.

Sacral nerve stimulation in fecal incontinence: are there factors associated with success?

PURPOSE: Sacral nerve stimulation has been used successfully in treating fecal incontinence. This study was designed to evaluate the proportion of patients with unsuccessful implantation despite positive test stimulation and to examine and compare factors associated with the success of the transitory and permanent sacral nerve stimulation. METHODS: A total of 61 patients (55 females; median age, 56 (range, 33-77) years) with refractory fecal incontinence underwent temporary stimulation. A 50 percent or greater improvement in the number of episodes of fecal incontinence or urgency was required to proceed to permanent implantation and was the criteria of success of permanent sacral nerve stimulation at the last follow-up visit in implanted patients. The factors compared between the success and the failure groups during temporary and permanent stimulation were patients' age and gender, diagnosis and characteristics of fecal incontinence, previous surgery, quality of life scores, anorectal manometry, endoanal ultrasound, and electrophysiologic tests performed before stimulation. RESULTS: Temporary stimulation was successful in 35 patients (57.4 percent). A permanent neurostimulation device was implanted in 33 patients. Age was the only factor related to success of the temporary stimulation (P=0.03). After permanent implantation, 31 percent of patients did not attain screening phase results for the number of episodes of fecal incontinence or urgency. A neurologic disorder was more frequently the origin of fecal incontinence in the success group compared with others (P=0.03). The left bulbocavernosus reflex was more frequently delayed in the success group than in the others (P=0.03), and a prolonged or absent bulbocavernosus reflex was more frequent in the success group than in the failure group (P=0.03). CONCLUSIONS: Patients with fecal incontinence from neurologic origins could be good candidates for sacral nerve stimulation.

Anal incontinence: the role of medical management.

BACKGROUND AND AIMS: Consensus recommendations suggest that patients with anal incontinence (AI) should be managed by medical treatment when indicated. Our aims were to prospectively evaluate from two different populations of patients: (1) the proportion of incontinent patients referred to a specialized center who were candidates for first line medical treatment (study 1); (2) the results of medical treatment in incontinent patients (study 2). METHODS: In study 1, standardized management of AI based on an algorithmic decision tree was applied to 287 incontinent patients (209 women, ranging from 16 to 84 years old). In study 2, 36 other incontinent patients with transit disorders (28 women, ranging from 29 to 86 years old) seen consecutively, were treated by a medical treatment of their transit disorders. The result of the medical treatment was objectively and subjectively evaluated after 2 months. RESULTS: Study 1: medical treatment was indicated in 126 of 287 patients (43.9%) (62 for diarrhea and 64 for constipation) while biofeedback was indicated in 52 patients (18.1%) and surgery specific for AI in 99 patients (34.5%). Eighty percent of the patients who were proposed conservative medical treatment were referred by their gastroenterologist or their general practitioner. Study 2: the continence score decreased from a median of 12 to 6.5 (P<0.001). 61% of patients regarded themselves as cured or improved after medical treatment. CONCLUSION: Conservative treatment can be proposed as a first line treatment in more than 50% of patients with anal incontinence referred to a specialized center. Medical treatment for anal incontinence associated with transit disorders improves continence.

Beneficial effect of amino acid supplementation, especially cysteine, on body nitrogen economy in septic rats.

BACKGROUND AND AIMS: Muscle wasting and increased synthesis of proteins and compounds involved in host defense characterize severe injury. The aims of the studies reported were to determine which amino acids exhibited an increased tissue content linked to anabolic processes in infected rats by comparison with healthy pair-fed controls, and to explore whether diets supplemented with these amino acids attenuate the catabolic response to infection. METHODS: Total amino acid content of the liver and the rest of the body were measured in control well-fed rats, in infected rats and their pair-fed controls 2 days after infection. In the nutritional protocols, infected rats were fed with a diet supplemented with alanine (basal diet), or threonine, serine, aspartate, asparagine and arginine (AA) or AA+cysteine (complete diet). RESULTS: Infection significantly increased liver total amino acid content by 38% for most amino acids. In contrast, the percentage increase was cysteine 79.3, threonine 45.3, aspartate-asparagine 46.3 and serine 46.5. Whole body without liver content of most amino acids decreased after infection due to the catabolic response, while the content of cysteine increased by 6% (P<0.05) and those of threonine and arginine did not decrease. After infection, animals fed the complete diet lost less weight than animals fed the basal diet (P<0.05). Furthermore, AA plus cysteine supplementation reduced significantly urinary nitrogen excretion and muscle wasting. CONCLUSIONS: The results provide evidence that diet supplementation with cysteine, threonine, serine, aspartate-asparagine and arginine supports the synthesis of vital proteins to spare body protein catabolism during infection.

Effects of enteral feeding on antroduodenal motility in healthy volunteers with 2 different fiber-supplemented diets: a 24-hour manometric study.

BACKGROUND: Antroduodenal motility during enteral nutrition remains poorly understood. The aim of the study was to evaluate antroduodenal motor activity during intermittent intragastric feeding and between enteral solutions supplemented with new recommended soluble or standard insoluble fibers. METHODS: Two 24-hour antroduodenal manometric studies were performed with a interval of 1 week in 8 healthy volunteers. Two similar enteral diets except for fiber (soluble vs insoluble) were separately assessed in random order at 2 intervals (lunch and dinner) for 2 hours each. Phase III was studied during three 6 hour-periods (after lunch, after dinner, and at night). The other quantitative manometric parameters were studied before (1 hour), during (2 hours), and after (2 hours) lunch and dinner. RESULTS: During the 2-hour postinfusion period, phase III reoccurred in 14 cases during the day and in 16 cases during the night. Phase III was always interrupted during feeding, which reoccurred in 14 cases during the 2-hour postinfusion period and in 16 cases during the after-dinner period. Nocturnal phase III was more frequent, lasted longer, with a lower amplitude than the diurnal phase. Addition of either soluble or insoluble fiber did not appear to have an influence on phase III or on the antroduodenal motor activity. CONCLUSIONS: Intragastric feeding interrupted phase III at the antroduodenal stage during infusion but was correlated with interdigestive motility. Antroduodenal motility did not significantly change either during or after intragastric feeding. The addition of either soluble or insoluble fiber does not seem to have an influence on gastroduodenal motor response to intermittent intragastric feeding.

Efficacy of indomethacin 0.1% and fluorometholone 0.1% on conjunctival inflammation following chronic application of antiglaucomatous drugs.

BACKGROUND: Subclinical conjunctival inflammation has been shown to have a deleterious effect on the outcome of filtering surgery. The study was designed to assess the efficacy and safety of a non-steroidal anti-inflammatory ophthalmic solution (preservative-free indomethacin 0.1%) on conjunctival inflammation following chronic application of antiglaucomatous drugs, in comparison with a steroidal ophthalmic solution (preserved fluorometholone). METHODS: Eighty-nine glaucomatous patients were included in a randomised, multicentre study comparing two parallel groups of treatment given on the basis of 1 drop 4 times daily for 1 month before filtering surgery. Patients had been treated with one or more antiglaucomatous drugs for at least 3 years. The routine antiglaucomatous treatment was continued during the study. Evaluations were carried out at baseline and after 30 days of treatment. Conjunctival inflammation was assessed under masked conditions by means of conjunctival impression analysis which determined the percentage of cells expressing HLA-DR. The ocular surface was also examined using the fluorescein test and lissamine green staining. RESULTS: Paired conjunctival impression specimens available both on day 0 (D0) and day 30 (D30) involved 49 patients. Among them, 34 eyes had a positive expression of HLA-DR at inclusion. On D30, in patients positive to HLA-DR on D0, the percentage of cells expressing HLA-DR had significantly decreased in both treatment groups: the mean reduction was 29.7% from a baseline value of 51.4% in the indomethacin group ( P=0.019) and 32.5% from a baseline value of 48.7% in the fluorometholone group ( P<0.001). There was no significant difference between groups. Seven cases of drug-related superficial punctate keratitis were observed on D30 by means of a fluorescein test: one in the indomethacin group and six in the fluorometholone group. CONCLUSION: Both anti-inflammatory eyedrops were effective in reducing subclinical conjunctival inflammation before filtering surgery. Regarding superficial punctate keratitis, the corneal tolerance of preservative-free indomethacin 0.1% eyedrops seemed to be better than that of preserved fluorometholone eyedrops.