Sex-related differences of bone properties of pelvic limb and bone metabolism indices in 14-month-old ostriches (Struthio camelus).

1. Sex-related differences of long pelvic limb bones and serum bone metabolism indices were evaluated in 14-month-old female (N = 7) and male (N = 7) ostriches of similar body weights. 2. Densitometric parameters of femur, tibia and tarsometatarsus were determined using quantitative computed tomography (volumetric bone mineral density, calcium hydroxyapatite density and mean volumetric bone mineral density) and dual energy X-ray absorptiometry (bone mineral density and bone mineral content) methods. Geometrical parameters such as cortical bone area, cross-sectional area, second moment of inertia, mean relative wall thickness and cortical index were determined in the midshaft of bones. Mechanical properties of bones (maximum elastic strength and ultimate strength) were evaluated using three-point bending test. Serum concentrations of free amino acids, osteocalcin, N-terminal propeptide of type I procollagen, C-terminal telopeptides of type II collagen and total antioxidative capacity were also determined. 3. Bone weight and relative bone weight of all bones were significantly higher in males than in females. Significantly lower values of trabecular bone mineral density and calcium hydroxyapatite density were found in the trabecular bone of tibia in males. The highest number of the sex-related differences was observed in the tarsometatarsus where bone length, bone mineral content, cortical bone area, cross-sectional area and ultimate strength were higher in males. Serum concentrations of taurine, hydroxyproline, valine and isoleucine were significantly higher in males. 4. Higher loading of the tarsometatarsus in comparison to femur and tibia may be an important factor interacting with sex hormones in regulation of bone formation and mineralisation processes. Sex-related differences of bone properties were associated with increased serum concentration of selected amino acids in males.

Effect of riluzole (Rilutek) treatment on plasma amino acid percentages in amyotrophic lateral sclerosis patients.

The aim of the study was to investigate the effect of riluzole (Rilutek) treatment on plasma amino acids (AA) percentage capacity in amyotrophic lateral sclerosis (ALS) patients. Excitatory AA may be important in the pathogenesis of ALS. Riluzole is a neuroprotective drug that blocks glutamatergic neurotransmission in the central nervous system. The study was conducted at the Department of Neurology, University School of Medicine in Lublin. The study comprised 20 ALS patients. Plasma AA were measured by automated ion-exchange chromatography before and after 3 months of riluzole treatment. The study has shown a significant decrease in serine percentage capacity and a significant increase in isoleucine percentage capacity in the plasma of the ALS patients, however the plasma excitatory AA percentage capacity was not significantly changed after 3 months of the riluzole treatment. Our investigations revealed that riluzole does not significantly influence the majority of plasma AA percentage capacity in ALS patients.

Plasma amino acids percentages in amyotrophic lateral sclerosis patients.

The aim of the study was to examine plasma amino acids (AA) percentages in amyotrophic lateral sclerosis (ALS) patients. Altered metabolism of AA, especially excitatory AA in ALS, has been reported. The investigation was conducted at the Department of Neurology, University School of Medicine in Lublin. The study comprised 50 patients; 20 persons with ALS and 30 controls. Plasma AA were measured by automated ion-exchange chromatography. The results show significantly lower percentages of plasma tyrosine, valine, methionine, leucine, and isoleucine and significantly higher percentages of plasma glutamine and serine in ALS than in controls. The clinical state significantly influenced the percentage of plasma phenylalanine and alanine. Our study shows significant changes in some plasma AA percentages in ALS; however, excitatory AA percentages did not differ from the control subjects.

Plasma amino acids concentration in amyotrophic lateral sclerosis patients.

Previous investigations showed an impairment of amino acids (AA) metabolism in amyotrophic lateral sclerosis (ALS). It was hypothesized that excitatory AA may play an important role in the etiopathogenesis of this disease. The aim of the study was to determine plasma AA concentrations in ALS patients, and to examine the relationship between AA and the clinical state of ALS patients, the type of ALS onset and the duration of the disease. The study involved 20 ALS patients and 30 control group people. The AA analysis was performed by ion - exchange chromatography on an automatic AA analyser. The results showed significantly decreased concentrations of valine, isoleucine, leucine, tyrosine and aspartate in the plasma of the whole group of ALS patients compared to the control group, and a significantly decreased concentration of arginine in the patients with a long duration of ALS compared to the patients with a short duration. The clinical state of ALS patients significantly influenced only plasma alanine concentration. Other plasma AA concentrations were not significantly associated with clinical parameters of the disease. Our study confirms that metabolic abnormalities concerning AA exist in ALS patients. However, the normal plasma glutamate concentration observed in this study in the whole group of ALS patients compared to the controls does not exclude that this excitatory AA may play a role in neurodegeneration in ALS.