A previous study has demonstrated that the soleus H reflex is facilitated in association with voluntary teeth clenching in proportion with biting force in humans. The present study tried to elucidate the functional significance of this facilitation of the soleus H reflex, by examining 1) whether the facilitation of the H reflex is reciprocal or nonreciprocal between the ankle extensors and flexors and 2) whether the reciprocal Ia inhibition of crural muscles is facilitated or depressed in association with voluntary teeth clenching. The H reflex of the pretibial muscles was evoked by stimulation of the common peroneal nerve in seven healthy subjects with no oral dysfunction. The pretibial H reflex was facilitated in association with voluntary teeth clenching in a force-dependent manner. The facilitation started preceding the onset of electromyographic activity of the masseter muscle. Stimulation of the common peroneal nerve at low intensities subthreshold for evoking the M wave of the pretibial muscles inhibited the soleus H reflex after a short latency corresponding with a disynaptic inhibition, indicating that the reciprocal Ia inhibition was depressed in association with voluntary teeth clenching. Thus, the present study has shown that voluntary teeth clenching evokes a nonreciprocal facilitation of ankle extensor and flexor muscles and attenuated reciprocal Ia inhibition from the pretibial muscles to the soleus muscle. It is concluded that voluntary teeth clenching contributes to improve stability of stance rather than smoothness of movements.
To develop novel therapeutic and diagnostic methods for esophageal cancer, it is important to understand the precise biological mechanism. Micro-RNAs (miRNAs) seem to be crucial factors in diverse regulation pathways. In this study, we analyzed the expression of mature miRNAs in esophageal squamous cell carcinoma (ESCC). The expression of 73 miRNAs was quantified by qRT-PCR in 30 primary ESCC specimens. We examined the correlation between miRNA expressions and the clinicopathological factors and prognosis of ESCC. The Kaplan-Meier survival curves showed that the high expression levels of 6 of the 72 miRNAs correlated with significantly lower patient survival rates. The overexpression of miR-129 was identified as a significant and independent prognostic factor (P = 0.031) in surgically treated ESCC patients. The hazard ratio for the prediction of early death was 18.11 for high versus low expression levels of miR-129. Similar results were obtained from an analysis performed on an additional 19 patients (test cohort) (P = 0.0057, for training cohort; P = 0.011, for test cohort; log-rank test). This experiment supports the notion that the high miR-129 expression levels, as observed in this study, might play a important role in the development of esophageal cancer.
Aims. Vagus nerve stimulation (VNS) is an established option of adjunctive treatment for patients with drug-resistant epilepsy, however, evidence for long-term efficacy is still limited. Studies on clinical outcomes of VNS in Asia are also limited. We report the overall outcome of a national, prospective registry that included all patients implanted in Japan. Methods. The registry included patients of all ages with all seizure types who underwent VNS implantation for drug-resistant epilepsy in the first three years after approval of VNS in 2010. The registry excluded patients who were expected to benefit from resective surgery. Efficacy analysis was assessed based on the change in frequency of all seizure types and the rate of responders. Changes in cognitive, behavioural and social status, quality of life (QOL), antiepileptic drug (AED) use, and overall AED burden were analysed as other efficacy indices.Results. A total of 385 patients were initially registered. Efficacy analyses included data from 362 patients. Age range at the time of VNS implantation was 12 months to 72 years; 21.5% of patients were under 12 years of age and 49.7% had prior epilepsy surgery. Follow-up rate was >90%, even at 36 months. Seizure control improved over time with median seizure reduction of 25.0%, 40.9%, 53.3%, 60.0%, and 66.2%, and responder rates of 38.9%, 46.8%, 55.8%, 57.7%, and 58.8% at three, six, 12, 24, and 36 months of VNS therapy, respectively. There were no substantial changes in other indices throughout the three years of the study, except for self/family-accessed QOL which improved over time. No new safety issues were identified. Conclusions. Although this was not a controlled comparative study, this prospective national registry of Japanese patients with drug-resistant epilepsy, with >90% follow-up rate, indicates long-term efficacy of VNS therapy which increased over time, over a period of up to three years. The limits of such trials, in terms of AED modifications and during follow-up and difficulties in seizure counting are also discussed.
Dopa decarboxylase (DDC; aromatic-Lamino-acid decarboxylase; aromatic-L-amino-acid carboxylyase, EC 4.1.1.28) was purified from rat liver and its partial sequence was determined. Synthetic oligonucleotides were used to construct and screen rat liver cDNA libraries, and three clones were isolated and sequenced. The 2 kilobases of DDC cDNA cloned consisted of a 5'-noncoding segment of 78 nucleotides, a coding region of 1440 nucleotides, and a 3'-noncoding region of 438 nucleotides. The encoded protein of 480 amino acid residues had a molecular weight of 54,000. A special feature of the primary structure of rat DDC was a repeating structure consisting of 29 amino acid residues. A sequence of 58 amino acid residues, including this repeating structure of rat DDC, was found to show homologies with those of rat tyrosine hydroxylase, human dopamine j3-hydroxylase, and bovine phenylethanolamine N-methyltransferase, other mammalian enzymes that synthesize catecholamines. These results indicate that catecholamine biosynthetic enzymes are structurally related and suggest that their homologous domains are important for catechol-protein interactions.The biosynthetic pathway of catecholamines has been well established and four enzymes-tyrosine hydroxylase [TH; tyrosine 3-monooxygenase; L-tyrosine, tetrahydropteridine: oxygen oxidoreductase (3-hydroxylating), EC 1.14.16.2], dopa decarboxylase (DDC; aromatic-L-amino-acid decarboxylase; aromatic-L-amino-acid carboxy-lyase, EC 4.1.1.28), dopamine P-hydroxylase [DBH; dopamine f3-monooxygenase; 3,4-dihydroxyphenethylamine, ascorbate: oxygen oxidoreductase (P-hydroxylating), EC 1.14.17.1], and phenylethanolamine N-methyltransferase (PNMT; S-adenosyl-L-methionine:phenylethanolamine N-methyltransferase, EC 2.1.1.28)-are known to be involved in biosynthesis of epinephrine from tyrosine. Recently, three of these enzymes (all but DDC) were cloned (1-3) and it became possible to investigate the regulation of these steps of catecholamine synthesis at the molecular level. DDC catalyzes decarboxylation not only of dopa to dopamine but also of 5-hydroxytryptophan to serotonin (4-7), and it is the sole enzyme necessary in both catecholamine and indoleamine biosynthesis. The enzyme is found in neural tissues and also in peripheral organs, especially liver and kidney. But there are no reports concerning the regulation of DDC expression in neural tissue, nor is it known why high activity of DDC is expressed in liver and kidney. Recently, the DDC gene of Drosophila was cloned and sequenced (8), but in Drosophila >90% ofthe DDC is concerned with cuticle sclerotization (9).We have purified rat liver DDC, obtained polyclonal and monoclonal antibodies to it, and determined some of its enzymological properties (10). We have also studied the difference between rat DDC and rat histidine decarboxylase (L-histidine carboxy-lyase, EC 4.1.1.22), which synthesizes histamine (11). Molecular cloning and sequencing of rat DDC cDNA should be useful in understanding the regulation of the mammalian DDC gene,...
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