New insights into tryptophan and its metabolites in the regulation of bone metabolism.

Osteoporosis, a debilitating disease caused by an imbalance between the action of osteoblasts and osteoclasts, is becoming an increasing problem in today's aging population. Although many advances in this field have addressed certain aspects of disease progression and pain management, new approaches to treatment are required. This review focuses on the influence of tryptophan, its metabolites and their influence on bone remodeling. Tryptophan is a precursor to serotonin, melatonin, kynurenines and niacin. Changes of tryptophan levels were noticed in bone metabolic diseases. Moreover, some works indicate that tryptophan plays a role in osteoblastic differentiation. Serotonin can exert different effects on bones, which depend on site of serotonin synthesis. Gut-derived serotonin inhibits bone formation, whereas brain-derived serotonin enhances bone formation and decreases bone resorption. Melatonin, increased differentiation of human mesenchymal stem cells into the osteoblastic cell lineage. Results of melatonin action on bone are anabolic and antiresorptive. Activation of the second tryptophan metabolic pathway, the kynurenine pathway, is associated with osteoblastogenesis and can be implicated in the occurrence of bone diseases. Oxidation products like kynurenine stopped proliferation of bone marrow mesenchymal stem cells. This may result in inhibition of osteoblastic proliferation and differentiation. Kynurenic acid acts as an antagonist at glutamate receptors, which are expressed on osteoclasts. Quinolinic acid activates N-methyl-D-aspartate receptors. 3-hydroxyanthranilic acid exhibits pro-oxidant and antioxidant activity. Decreased concentration of 3-hydroxyanthranilic acid can be one of the causes of osteoporosis. 3-hydroxykynurenine reduced the viability of osteoblast-like cells. Picolinic acid exerted osteogenic effect in vitro. Kynurenine derivatives exert various effects on bones. Discovery of the exact mechanism of action of tryptophan metabolites on bones may take us a step closer to understanding the complicated mechanism of bone metabolism, which in turn may result in finding a new, effective therapy for treating bone diseases.

Leptin and ghrelin concentrations and weight loss in Parkinson's disease.

OBJECTIVES: To investigate the role of leptin, ghrelin, GH and IGF-1 in energy balance disturbances in Parkinson's disease (PD). MATERIALS AND METHODS: Thirty-nine patients were included: 11 PD patients with unintentional weight loss, 16 PD patients without weight loss and 12 controls. UPDRS, MMSE, MADRS, appetite scale, BMI, adipose tissue content, plasma leptin and active ghrelin concentrations and serum GH, IGF-1, TSH, T3 and T4, concentrations were evaluated. RESULTS: A lower plasma leptin concentration and a higher serum IGF-1 concentration were found in PD patients with weight loss. BMI and the content of adipose tissue were positively correlated with leptin concentration in all PD patients. Paradoxically, the lower BMI was, the lower plasma active ghrelin concentration was in PD patients with the weight loss. CONCLUSION: These findings confirm that changes of plasma leptin concentration occur in PD patients with loss of weight.

The antibodies against Bordetella pertussis in sera of patients with Parkinson's disease and other non-neurological diseases.

OBJECTIVES: It has been reported that the prevalance of parkinsonism might be associated with exposure to whooping cough. METHODS: Examination of levels of antibodies against Bordetella pertussis in serum using enzyme-linked immunosorbent assay (ELISA) tests [presence of IgG antibodies against filamentous hemagglutinin and pertussis toxin (PT)] were performed in 81 persons (including 45 patients with controls) (age-matched groups). RESULTS: Positive results were found in patients with Parkinson's disease (PD), patients with other non-inflammatory diseases, and controls (about 40-45% in each group). A detailed examination of separate responses (IgG and IgA antibodies against PT, and a whole cell immune response) and of the serum level of immunoglobulins IgG, IgA and IgM was also performed. CONCLUSION: Our results demonstrate numerous cases of whooping cough serum antibodies among the adult population (also among PD patients). The results of our research, i.e. a common occurrence of Bordetella pertussis infection do not provide evidence of relationship between PD and the above-mentioned infection.

[Anaplastic oligoastrocytoma of the spinal cord: diagnostic difficulties. Case report]. / Oligoastrocytoma anaplasticum rdzenia kregowego: trudnosci diagnostyczne. Opis przypadku.

The authors report a rare case of 49-years old woman with rapidly progressing anaplastic oligoastrocytoma primarily localized in the spinal cord. Increasing spastic paresis of the right lower limb was concomitant with decrease in superficial sensibility in this limb and the right side of the trunk below Th10 level, suggested a lesion within the spinal cord. However, it was the difficult confirming the diagnosis by spinal MR imaging, and the negative result of the first MR examination (performed 5 weeks after manifestation of first clinical symptoms of the disease) delayed surgical treatment. During the next 3 weeks the neurological syndrome increased to spastic paraparesis with sphincters dysfunction and decrease in superficial and vibratory sensibility within the lower limbs and the trunk below the Th10 level. The second MR examination of the spine revealed an intraspinal tumour at Th8-Th10 levels. Surgical (partial excision of the tumour) and radiation treatment was given. Histopathological examination of tumour tissue showed the presence of anaplastic oligoastrocytoma. During the follow-up of our patient we found cerebral foci, probably of metastatic origin ascending with cerebrospinal fluid. More than 5 months after the diagnosis was established the patient died of primary disease. The imaging parameters of both spinal MR examinations were similar, however, on second examination narrower field of vision was used. In both cases Magnevist was administered. Discussing factors which might be responsible for the false-negative result of spinal MR examination--the examination of choice for detection of proliferative transformation--the authors take artefacts connected with respiratory and circulatory function, peristaltic movements, and with field of vision into consideration.