Gerardo Bosco

Ketogenic diet in neuromuscular and neurodegenerative diseases.

An increasing number of data demonstrate the utility of ketogenic diets in a variety of metabolic diseases as obesity, metabolic syndrome, and diabetes. In regard to neurological disorders, ketogenic diet is recognized as an effective treatment for pharmacoresistant epilepsy but emerging data suggests that ketogenic diet could be also useful in amyotrophic lateral sclerosis, Alzheimer, Parkinsons disease, and some mitochondriopathies. Although these diseases have different pathogenesis and features, there are some common mechanisms that could explain the effects of ketogenic diets. These mechanisms are to provide an efficient source of energy for the treatment of certain types of neurodegenerative diseases characterized by focal brain hypometabolism; to decrease the oxidative damage associated with various kinds of metabolic stress; to increase the mitochondrial biogenesis pathways; and to take advantage of the capacity of ketones to bypass the defect in complex I activity implicated in some neurological diseases. These mechanisms will be discussed in this review.

Hyperbaric oxygen therapy in femoral head necrosis.

We evaluated hyperbaric oxygen (HBO) therapy on a cohort of patients with femoral head necrosis (FHN). This double-blind, randomized, controlled, prospective study included 20 patients with unilateral FHN. All were Ficat stage II, treated with either compressed oxygen (HBO) or compressed air (HBA). Each patient received 30 treatments of HBO or HBA for 6 weeks. Range of motion, stabilometry, and pain were assessed at the beginning of the study and after 10, 20, and 30 treatments by a blinded physician. After the initial 6-week treatment, the blind was broken; and all HBA patients were offered HBO treatment. At this point, the study becomes observational. Pretreatment, 12-month. and 7 year-follow-up magnetic resonance images were obtained. Statistical comparisons were obtained with nonparametric Mann-Whitney U test. Significant pain improvement for HBO was demonstrated after 20 treatments. Range of motion improved significantly during HBO for all parameters between 20 and 30 treatments. All patients remain substantially pain-free 7 years later: none required hip arthroplasty. Substantial radiographic healing of the osteonecrosis was observed in 7 of 9 hips. Hyperbaric oxygen therapy appears to be a viable treatment modality in patients with Ficat II FHN.

Propofol reduces infarct size and striatal dopamine accumulation following transient middle cerebral artery occlusion: a microdialysis study

Acute cerebral ischemia is associated with an increased extracellular dopamine accumulation. Attenuation or prevention of excessive dopamine accumulation alleviates the cerebral ischemic damage. Propofol, an intravenous anesthetic, has been suggested to have neuroprotective properties. The effect of propofol on dopaminergic neurotransmitters is unclear. The in vivo microdialysis technique was used in this study to examine the effect of propofol on infarct size and striatal dopamine accumulation in rat model of temporary middle cerebral artery occlusion. Sixteen rats were fitted with a right striatal microdialysis probe. Ischemia was induced by inserting a 4-0 monofilament nylon suture into the middle cerebral artery. Propofol was intravenously infused in eight rats during ischemia (60 min) and reperfusion (60 min) at an average dose of 36 mg/kg/h. Control rats (n=8) received vehicle infusion. The infarct size was determined at the end of the experiment. Propofol significantly reduced infarct size, the median (interquatile range) value was 6.84% (7.68%), significantly lower than that in the control group, which was 28.04% (32.28%) (p<0.01). The middle cerebral artery occlusion significantly increased dopamine accumulation in the striatum. Propofol infusion significantly attenuated this middle cerebral artery occlusion-induced dopamine accumulation. The data demonstrate that propofol, when administered during ischemia and reperfusion, provides neuroprotection in our middle cerebral artery occlusion in rat model. The data also suggest that attenuated dopamine accumulation may be one of the factors contributing to the neuroprotective property of propofol.

Ketosis, ketogenic diet and food intake control: a complex relationship

Though the hunger-reduction phenomenon reported during ketogenic diets is well-known, the underlying molecular and cellular mechanisms remain uncertain. Ketosis has been demonstrated to exert an anorexigenic effect via cholecystokinin (CCK) release while reducing orexigenic signals e.g., via ghrelin. However, ketone bodies (KB) seem to be able to increase food intake through AMP-activated protein kinase (AMPK) phosphorylation, gamma-aminobutyric acid (GABA) and the release and production of adiponectin. The aim of this review is to provide a summary of our current knowledge of the effects of ketogenic diet (KD) on food control in an effort to unify the apparently contradictory data into a coherent picture.

Beneficial effect of hyperbaric oxygen pretreatment on lipopolysaccharide-induced shock in rats.

1. We investigated the effect of hyperbaric oxygenation (HBO2) pretreatment on the production of exhaled nitric oxide (ENO) and the expression of lung inducible nitric oxide synthase (iNOS) by Escherichia coli lipopolysaccharide (LPS)‐induced shock in an experimental rat model.

Effects of Hypoxia on the Circadian Patterns in Men

We tested the hypothesis that acute hypoxia may alter the circadian pattern of body temperature in adult humans. Six healthy subjects were studied in normoxia, hypoxia (approximately 13% inspired O(2)), and again normoxia, each session lasting >24 h and spaced a few days apart, with a constant routine protocol of sustained wakefulness and minimal activity. Some parameters (e.g., tympanic and abdominal temperatures, heart rate) were recorded continuously; others (e.g., oxygen consumption and pulmonary ventilation) were monitored for approximately 10 min every 2 h. The amplitudes of the circadian oscillation of tympanic, abdominal, and calf skin temperatures were reduced in hypoxia, averaging, respectively, 61%, 80% and 50% of the normoxic amplitude. Oxygen consumption and pulmonary ventilation, which presented a circadian pattern in normoxia, had no longer significant oscillations during hypoxia, whereas the opposite was the case for heart rate and diastolic pressure. Therefore, acute hypoxia can disturb the normal circadian patterns and, specifically, depress those of body temperature. These effects, qualitatively similar to those observed in chronically hypoxic animals and humans, could contribute to sleep disturbances at high altitude.

EFFECTS OF HYPERBARIC OXYGEN ON GLUCOSE, LACTATE, GLYCEROL AND ANTI‐OXIDANT ENZYMES IN THE SKELETAL MUSCLE OF RATS DURING ISCHAEMIA AND REPERFUSION

1 Hyperbaric (HBO2) and topical oxygen represent two accepted options to oxygenate tissues. The aim of the present study was to investigate the effect of HBO2 on energy metabolism and anti‐oxidant enzymes in a rat model of ischaemia–reperfusion (IR) skeletal muscle injury. 2 In the first study, 16 rats were randomized to a HBO2‐treated group (Group 1; n = 8) and an untreated group (Group 2; n = 8). Under general anaesthesia, right hind limb ischaemia was produced by application of a rubber‐band tourniquet for 3 h. After 2 h ischaemia, Group 1 rats received HBO2 during the last hour of ischaemia. The HBO2 consisted of 100% oxygen delivered at 282.8 kPa absolute pressure. Group 2 rats were not treated. Following the ischaemic period, the tourniquet was released for 1 h. A microdialysis probe was used to sample lactate, glucose and glycerol concentrations in the muscle extracellular tissue every 15 min throughout each experiment. 3 In the second study, 24 rats were randomized into four groups (n = 6 each). The first two groups were subjected to the IR injury protocol outlined above and either treated (Group 1) or untreated (Group 2) with HBO2. Group 3 rats were anaesthetized, did not undergo IR injury, but underwent HBO2 treatment. Group 4 rats were anaesthetized but did not undergo either IR injury or HBO2 treatment. At end of each experiment, the biceps femoris muscle was removed and assayed for superoxide dismutase (SOD) and catalase (CAT) activity. Malondialdehyde (MDA) was measured to estimate the extent of membrane lipid peroxidation. 4 Three hours of skeletal muscle ischaemia resulted in a gradual decrease in the glucose concentration and a gradual increase in the lactate concentration within the extracellular fluid of the affected skeletal muscle tissue. Treatment with HBO2 had no effect on the glucose concentration; however, HBO2 significantly attenuated the ischaemia‐induced increase in lactate and glycerol. In both groups, glucose concentration increased rapidly during reperfusion; glucose concentration returned to pre‐ischaemic levels 15 min after reperfusion both with and without HBO2. 5 Catalase activity and MDA increased significantly after 1 h of reperfusion. The HBO2 attenuated the reperfusion‐induced increase in CAT activity and MDA. 6 The results of the study suggest that HBO2 may have some beneficial effect by decreasing lactate and glycerol levels and modulating anti‐oxidant enzyme activity in postischaemic skeletal muscle in our rat model of tourniquet‐induced IR skeletal muscle injury.

Long Term Successful Weight Loss with a Combination Biphasic Ketogenic Mediterranean Diet and Mediterranean Diet Maintenance Protocol

Weight loss protocols can only be considered successful if they deliver consistent results over the long term—a goal which is often elusive, so much so that the term “yo-yo” is used to describe the perennial weight loss/weight regain battle common in obesity. We hypothesized that a ketogenic Mediterranean diet with phytoextracts (KEMEPHY) combined with the acknowledged health benefits of traditional Mediterranean nutrition may favor long term weight loss. We analysed 89 male and female obese subjects, aged between 25 and 65 years who were overall healthy apart from being overweight. The subjects followed a staged diet protocol over a period of 12 months: 20 day of KEMEPHY; 20 days low carb-non ketogenic; 4 months Mediterranean normocaloric nutrition; a second 20 day ketogenic phase followed by 6 months of Mediterranean normocaloric nutrition. For the majority of subjects (88.25%) there was significant loss of weight (from 100.7 ± 16.54 to 84.59 ± 9.71 kg; BMI from 35.42 ± 4.11 to 30.27 ± 3.58) and body fat (form 43.44% ± 6.34% to 33.63% ± 7.6%) during both ketogenic phases followed by successful maintenance, without weight regain, during the 6 month stabilization phase with only 8 subjects failing to comply. There were also significant and stable decreases in total cholesterol, LDLc, triglycerides and glucose levels over the 12 month study period. HDLc showed small increases after the ketogenic phases but over the full 12 months there was no significant change. No significant changes were observed in ALT, AST, Creatinine or BUN. The combination of a biphasic KEMEPHY diet separated by longer periods of maintenance nutrition, based on the traditional Mediterranean diet, led to successful long term weight loss and improvements in health risk factors in a majority of subjects; compliance was very high which was a key determinant of the results seen.

Hyperbaric Oxygenation Ameliorates Indomethacin-Induced Enteropathy in Rats by Modulating TNF-α and IL-1β Production

The effect of hyperbaric oxygenation (HBO2) was investigated in a rat model of indomethacin-induced enteropathy. Enteropathy was induced by two subcutaneous injections of indomethacin (7.5 mg/kg) 24 hr apart. Six groups of rats (n=8) were treated with and without HBO2 (100% oxygen at 2.3 atm absolute) for 1 hr once or twice a day for 2 or 5 days. Disease activity index (DAI) and total ulcer length were measured. Other rats were randomized into two groups (n=16) with and without HBO2 (1 hr once a day) and four rats were killed in each group at 12, 24, 48, and 72 hr after the final injection of indomethacin. Serum and intestinal mucosal TNF-α, IL-1β, myeloperoxidase (MPO), and iNOS expression was measured. HBO2 treatment significantly attenuated indomethacin -induced intestinal ulceration and improved DAI. Indomethacin increased MPO activity and iNOS expression, and these were reduced by HBO2 treatment, with a concomitant reduction in TNF-α and IL-1β. Our data suggest that HBO2 treatment has a beneficial effect on indomethacin-induced enteropathy and this effect is possibly mediated by decreased production of TNF-α and IL-1β.

Effects of n-3 Polyunsaturated Fatty Acids (ω-3) Supplementation on Some Cardiovascular Risk Factors with a Ketogenic Mediterranean Diet

Background: the ketogenic diet (KD) has become a widely used nutritional approach for weight loss. Some of the KD’s positive effects on metabolism and cardiovascular risk factors are similar to those seen after n-3 polyunsaturated fatty acids (ω-3) supplementation. We hypothesized that a ketogenic Mediterranean diet with phytoextracts combined with ω-3 supplementation may have increased positive effects on cardiovascular risk factors and inflammation. Methods: We analyzed 34 male overweight subjects; aged between 25 and 65 years who were overall healthy apart from overweight. The subjects followed a ketogenic diet protocol for four weeks; with (KDO3) or without (KD) ω-3 supplementation. Results: All subjects experienced a significant loss of body weight and body fat and there was no significant differences between treatment (body weight: KD—4.7 kg, KDO3—4.03 kg, body fat KD—5.41 kg, KDO3—5.86 kg). There were also significant decreases in total cholesterol, LDL-c, and glucose levels. Triglycerides and insulin levels decreased more in KDO3 vs. KD subjects, with a significant difference. All the investigated inflammatory cytokines (IL-1β, IL-6, TNF-α) decreased significantly in KDO3 subjects whilst only TNF-α showed a significant decrease in KD subjects over the 12 month study period. No significant changes were observed in anti-inflammatory cytokines (IL-10 and IL-1Ra), creatinine, urea and uric acid. Adiponectin increased significantly only in the KDO3 group. Conclusions: ω-3 supplementation improved the positive effects of a ketogenic Mediterranean diet with phytoextracts on some cardiovascular/metabolic risk factors and inflammatory state.