Muscle spindle and fusimotor activity in locomotion

Mammals may exhibit different forms of locomotion even within a species. A particular form of locomotion (e.g. walk, run, bound) appears to be selected by supraspinal commands, but the precise pattern, i.e. phasing of limbs and muscles, is generated within the spinal cord by so-called central pattern generators. Peripheral sense organs, particularly the muscle spindle, play a crucial role in modulating the central pattern generator output. In turn, the feedback from muscle spindles is itself modulated by static and dynamic fusimotor (gamma) neurons. The activity of muscle spindle afferents and fusimotor neurons during locomotion in the cat is reviewed here. There is evidence for some alpha–gamma co-activation during locomotion involving static gamma motoneurons. However, both static and dynamic gamma motoneurons show patterns of modulation that are distinct from alpha motoneuron activity. It has been proposed that static gamma activity may drive muscle spindle secondary endings to signal the intended movement to the central nervous system. Dynamic gamma motoneuron drive appears to prime muscle spindle primary endings to signal transitions in phase of the locomotor cycle. These findings come largely from reduced animal preparations (decerebrate) and require confirmation in freely moving intact animals.     

Sensitivity and specificity of screening tools and smear microscopy in active tuberculosis case finding

Setting

Community based five pulmonary tuberculosis (PTB) surveys among adults.

Factors associated with poor self-reported function and quality of life in patients with end-stage knee or hip osteoarthritis immediately prior to total joint arthroplasty

IntroductionThe aim was to evaluate patients’ perception of function and physical and mental dimensions of health-related quality of life (HRQoL) in patients with end-stage knee or hip osteoarthritis (OA) immediately prior to surgery and to identify the factors associated with the outcomes.Material and methodsThe study included 200 patients with end-stage OA (100 knee OA and 100 hip OA patients). Self-reported physical function was assessed using the Oxford Knee Score or Oxford Hip Score. Physical and mental dimensions of HRQoL were assessed using the physical and mental component summary scores of the 36-Item Short-Form Health Survey. Multivariate linear regression analysis was used to identify the sociodemographic, clinical and psychological factors associated with self-reported function and physical and mental dimensions of HRQoL.ResultsEnd-stage knee or hip OA patients had poor function and physical dimension of HRQoL, while the mental dimension of HRQoL was not impaired. In knee OA, pain, flexion range of motion (ROM), catastrophizing, and anxiety were significantly associated with self-reported function (explained 56% of the variance), whereas catastrophizing explained 10% of the variance of the physical dimension of HRQoL. In hip OA, flexion ROM, catastrophizing and being employed were significantly associated with self-reported function (explained 44% of the variance), whereas catastrophizing and flexion ROM explained 34% of the variance of the physical dimension of HRQoL.ConclusionsMany investigated factors were associated with poor self-reported function and HRQoL in knee and hip OA. However, the most important factors for both knee and hip OA were catastrophizing and flexion ROM.     

Potential hepatoprotective effects of fullerenol C60(OH)24 in doxorubicin-induced hepatotoxicity in rats with mammary carcinomas

The aim of this study was to investigate the potential protective role of fullerenol C60(OH)24 on doxorubicin-induced liver toxicity using in vivo (female Sprague-Dawley rats) and in vitro (human hepatocellular carcinoma - HepG2; colorectal adenocarcinoma cell lines - Caco-2) approaches. The first (healthy control) and second (control with chemically induced mammary carcinomas) group received saline only. The third, fourth and fifth group (all with breast cancer) were injected (i.p.) with a single dose of doxorubicin (8mg/kg), doxorubicin/fullerenol (100mg/kg of fullerenol 30min before administration of 8mg/kg doxorubicin) and fullerenol (100mg/kg), respectively. Two days after treatment, the rats were sacrificed. Results showed that treatment with doxorubicin alone caused significant changes in the serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH) and alpha-hydroxybutyrate dehydrogenase (alpha-HBDH), as well as in the levels of malondialdehyde (MDA), glutathione (GSH), glutathione peroxidase (GSH-Px), total antioxidant status (TAS), glutathione reductase (GR), catalase (CAT) and superoxide dismutase (SOD) in the liver tissue. These effects were significantly reduced for all investigated parameters by pre-treatment with fullerenol but not for the MDA and GSH level. The HepG2 and Caco-2 cell lines were continuously treated with fullerenol for 12h, 24h, 48h and 96h at concentrations of 10microg/mL and 44microg/mL. With the aim of evaluating the modulating activity of fullerenol on doxorubicin-induced hepatotoxicity, the cell lines were simultaneously treated with doxorubicin (1microm; 5microm) and fullerenol (10microg/mL; 44microg/mL) in different combinations. When the cells are treated with 5microm doxorubicin along with the fullerenol, we can see a significant improvement of the cell capability during the entire time-line. We can conclude that fullerenol has cytotoxic effects on HepG2 by itself, but when the oxidative stress is too high the cytotoxic effects of fullerenol are overcome by its protective role as a strong antioxidant compound.