Oxfendazole induces protein catabolism and gluconeogenesis in experimental neurocysticercosis

Neurocysticercosis (NCC) is an endemic public health disease of the central nervous system highly related to epilepsy and seizures. Taenia crassiceps is an experimental model used for NCC and biochemical studies of the host-parasite relationship. For the past 50 years the NCC therapeutic treatment is performed with albendazole (ABZ) and praziquantel which opens a gap for new therapies due to parasitic resistance and other adverse effects of the drugs. Oxfendazole (OXF) is an albendazole derivative with efficacy against tissue cestodes of veterinary importance. The aim of this study was to determine the metabolic impact of OXF on T. crassiceps cysticerci intracranially inoculated in Balb/C mice. The animals were intracranially inoculated with T. crassiceps cysticerci and 30 days later received single dose oral treatment of OXF, ABZ and NaCl 0.9% (control group). The metabolic impact was quantified through the detection of metabolites from glycolysis, anaerobic fermentation of lactate and propionate, tricarboxylic acid cycle, protein catabolism, fatty acids oxidation. The differences observed in the concentrations of metabolites from the OXF treated group showed that the drug induced gluconeogenesis, increase in protein catabolism, fatty acids oxidation and propionate fermentation in comparison to the ABZ and control treated groups. In conclusion, OXF induced greater metabolic impact in T. crassiceps cysticerci than the standard NCC treatment, ABZ, showing that it may represent an alternative drug for its treatment.

In vitro metabolic stress induced by nitazoxanide and flubendazole combination in Taenia crassiceps cysticerci

Taenia crassiceps is often used as experimental model for T. solium cysticercosis studies. Currently cysticercosis antiparasitic treatment is based on albendazole and praziquantel which may present side effects and parasitic resistance. The search for other antiparasitic drugs is necessary. Nitazoxanide (NTZ) and flubendazole (FLB) are broad spectrum antiparasitic drugs that present anti-cysticercosis effect. Metabolic analyses help to determine the impact of these drugs on parasites. The aim of this study was to determine the impact on the production and excretion of organic metabolites in T. crassiceps cysticerci after in vitro exposure to NTZ and FLB, isolated or in combination. T. crassiceps cysticerci were culture in RPMI medium and exposed to 10μg/mL of NTZ, 10μg/mL of FLB or 10μg/mL of NTZ +10μg/mL of FLB. 24h after exposure, the parasites were chromatographic analyzed to determine the impact of these drugs on glycolysis, homolactic fermentation, tricarboxylic acid cycle, fatty acids oxidation and proteins catabolism. It was possible to determine that the drugs combination induced greater metabolic impact on cysticerci in comparison to the isolated drugs exposure. The drugs combination induced gluconeogenesis, metabolic acidosis, increase in tricarboxylic acid cycle and in proteins catabolism. While the NTZ isolated exposure induced metabolic acidosis and protein catabolism and the FLB isolate exposure induced gluconeogenesis and protein catabolism. These results show that the combination of drugs with different modes of action increase the antiparasitic effect and may be indicated as alternative cysticercosis treatments.

Calcium metabolism, vitamin D and bone mineral density after bariatric surgery

SUMMARY

Lower bone mineral density, vitamin D deficiency, lower lean body mass, greater loss of excess weight, and increased bone turnover are complications found after bariatric surgery correlated in the literature with increased risk of fractures. The prevention and treatment of such complications should begin immediately after surgery.

INTRODUCTION

The aims of the study were to evaluate bone mass in patients undergoing bariatric surgery by the Wittgrove technique after 1 year of the procedure and correlate it with body composition, weight loss, 25OH vitamin D levels, and markers of bone metabolism.

METHODS

The operated group (OG) participated in a clinical consultation; a blood sample taken and a body composition; and bone mineral density assessment by dual energy X-ray absorptiometry (DXA). The results were compared with a control group (CG).

RESULTS

Fifty-six subjects in the OG and 27 in the CG were included. The bone mineral density (BMD), after the surgery, at the lumbar spine (LS) was lower in the OG than in the CG. There was a positive correlation between total body (TB) BMD with 25OHD, body mass index (BMI), and lean mass and an inverse correlation with percentage of excess weight loss (%EWL). Vitamin D deficiency was seen in 60.41% (OG) and in 16.6% (CG). PTH was higher in the OG, with secondary hyperparathyroidism in 41.7%. In 26.5% and 14.2% of the OG, ALP and OC levels were above the reference values. In <50 years, elevated values of carboxy-terminal telopeptide (CTX) were found in 66.7% of patients. A difference was observed in the variation of CTX between 12 and 18 months when compared to over 24 months.

CONCLUSIONS

Lower BMD was observed, correlated with lower lean body mass and greater loss of excess weight. Vitamin D deficiency with high prevalence of secondary hyperparathyroidism and high bone turnover was detected. The prevention of bone loss should be initiated in the first months after surgery, which is a period associated with severe muscle loss and increased bone turnover.

Differential effects of aging on spatial contrast sensitivity to linear and polar sine-wave gratings

Changes in visual function beyond high-contrast acuity are known to take place during normal aging. We determined whether sensitivity to linear sine-wave gratings and to an elementary stimulus preferentially processed in extrastriate areas could be distinctively affected by aging. We measured spatial contrast sensitivity twice for concentric polar (Bessel) and vertical linear gratings of 0.6, 2.5, 5, and 20 cycles per degree (cpd) in two age groups (20-30 and 60-70 years). All participants were free of identifiable ocular disease and had normal or corrected-to-normal visual acuity. Participants were more sensitive to Cartesian than to polar gratings in all frequencies tested, and the younger adult group was more sensitive to all stimuli tested. Significant differences between sensitivities of the two groups were found for linear (only 20 cpd; P<0.01) and polar gratings (all frequencies tested; P<0.01). The young adult group was significantly more sensitive to linear than to circular gratings in the 20 cpd frequency. The older adult group was significantly more sensitive to linear than to circular gratings in all spatial frequencies, except in the 20 cpd frequency. The results suggest that sensitivity to the two kinds of stimuli is affected differently by aging. We suggest that neural changes in the aging brain are important determinants of this difference and discuss the results according to current models of human aging.

Taenia crassiceps: host treatment alters glycolisis and tricarboxilic acid cycle in cysticerci

Human cysticercosis by Taenia crassiceps is rare although it is considered of zoonotic risk, especially to immunocompromised individuals. Albendazole and praziquantel are widely used and effective in its treatment. Their active forms inhibit the glucose uptake by the parasite and induce muscle contractions that alter its glycogen levels interfering in the energetic metabolism of the parasite and leading to its death. The aim of this study was to evaluate alterations in glycolysis, the tricarboxylic acid cycle and glucose concentrations caused by low dosage treatments of the hosts with albendazole and praziquantel. Therefore, T. crassiceps intraperitoneally infected mice were treated by gavage feeding with 5.75 or 11.5 mg/kg of albendazole and 3.83 or 7.67 mg/kg of praziquantel. The treated mice were euthanized after 24 h and the cysticerci collected were morphologically classified into initial, larval or final phases. Concentrations of the organic acid produced and glucose were evaluated to detect alterations into the glycolysis and the tricarboxylic acid cycle pathways through chromatography and spectrophotometry. The low dosage treatment caused a partial blockage of the glucose uptake by the cysticerci in spite of the non significant difference between its concentrations. An activation of the tricarboxylic acid cycle was noted in the cysticerci that received the treatment due to an increase in the production of citrate, malate and α-ketoglutarate and the consumption of oxaloacetate, succinate and fumarate. The detection of α-ketoglutarate indicates that the cysticerci which were exposed to the drugs after host treatment present different metabolic pathways than the ones previously described after in vitro treatment.