Timing of Surgical Intervention with Cochlear Implant in Patients with Large Vestibular Aqueduct Syndrome

Objectives

(1) To report the speech perception and intelligibility results of Mandarin-speaking patients with large vestibular aqueduct syndrome (LVAS) after cochlear implantation (CI); (2) to compare their performance with a group of CI users without LVAS; (3) to understand the effects of age at implantation and duration of implant use on the CI outcomes. The obtained data may be used to guide decisions about CI candidacy and surgical timing.

Methods

Forty-two patients with LVAS participating in this study were divided into two groups: the early group received CI before 5 years of age and the late group after 5. Open-set speech perception tests (on Mandarin tones, words and sentences) were administered one year after implantation and at the most recent follow-up visit. Categories of auditory perception (CAP) and Speech Intelligibility Rating (SIR) scale scores were also obtained.

Results

The patients with LVAS with more than 5 years of implant use (18 cases) achieved a mean score higher than 80% on the most recent speech perception tests and reached the highest level on the CAP/SIR scales. The early group developed speech perception and intelligibility steadily over time, while the late group had a rapid improvement during the first year after implantation. The two groups, regardless of their age at implantation, reached a similar performance level at the most recent follow-up visit.

Conclusion

High levels of speech performance are reached after 5 years of implant use in patients with LVAS. These patients do not necessarily need to wait until their hearing thresholds are higher than 90 dB HL or PB word score lower than 40% to receive CI. They can do it “earlier” when their speech perception and/or speech intelligibility do not reach the performance level suggested in this study.     

A possible strategy against head and neck cancer: in silico investigation of three-in-one inhibitors

Overexpression of epidermal growth factor receptor (EGFR), Her2, and uroporphyrinogen decarboxylase (UROD) occurs in a variety of malignant tumor tissues. UROD has potential to modulate tumor response of radiotherapy for head and neck cancer, and EGFR and Her2 are common drug targets for the treatment of head and neck cancer. This study attempts to find a possible lead compound backbone from TCM Database@Taiwan (http://tcm.cmu.edu.tw/) for EGFR, Her2, and UROD proteins against head and neck cancer using computational techniques. Possible traditional Chinese medicine (TCM) lead compounds had potential binding affinities with EGFR, Her2, and UROD proteins. The candidates formed stable interactions with residues Arg803, Thr854 in EGFR, residues Thr862, Asp863 in Her2 protein, and residues Arg37, Arg41 in UROD protein, which are key residues in the binding or catalytic domain of EGFR, Her2, and UROD proteins. Thus, the TCM candidates indicated a possible molecule backbone for evolving potential inhibitors for three drug target proteins against head and neck cancer.

An animated interactive 3D complement (I3DC) is available in Proteopedia at http://proteopedia.org/w/Journal:JBSD:35     

几种常用杀虫剂对蚜虫天敌——瓢虫的影响

作者等就11种常用杀虫剂对蚜虫的重要天敌——瓢虫进行了毒性测定,观察了它们对瓢虫的各个虫态的影响。 供试药剂 20％乐果乳剂、50％敌敌畏乳剂、50％对硫磷乳剂、50％内吸磷乳剂、25％三硫磷乳剂、50％杀螟硫磷乳剂、50％磷胺液剂、20％酚开普敦乳剂、6％丙体六六六乳剂、6％丙体六六六可湿性粉(W、P)、2.5％鱼籐精乳剂。 供试瓢虫 异色瓢虫Leis axyridis,室内饲养;龟纹瓢虫Propylaea japonica,田间采回。     

On the chemical basis of chromosome banding patterns.

A comparative study of the staining characteristics of four reagents for human chromosomes has been carried out. The four reagents are: (I) quinacrine mustard, as an alkylating agent, (II) the dihydroxy derivative of quinacrine mustard, (III) quinacrine, and (IV) 9-amino-6-chloro-2-methoxyacridine. The last reagent does not possess the amino substituted side chain even though it has the same intercalating nucleus. Comparison of the first three compounds in their staining and banding behavior suggested the initial step leading to banding may be the displacement of the nucleoprotein sites in hcromosomes. The Q and G banding could be blocked experimentally by treating the chromosome preparation with dimethylamine solution. This result may suggest that these sites have weaker basic proteins (nonhistone proteins?). The use of compound IV, which does not have the side chain in the molecule but does have the same intercalating chromophore, did not lead to banding and gives indirect support to this hypothesis. A combined use of compound IV and quinacrine may be useful for the determination of total DNA vs. banding DNA.     

An essential tryptophan residue for rabbit muscle creatine kinase

The tryptophan residues in rabbit muscle creatine kinase (ATP:creatine N-phosphotransferase, EC 2.7.3.2) have been modified by dimethyl(2-hydroxy-5-nitrobenzyl) sulfonium bromide after reversible protection of the reactive SH groups. The modification of two tryptophan residues as measured by spectrophotometric titration leads to complete loss of enzymatic activity. Control experiments show that reversible protection of the reactive SH groups as S-sulfonates followed by reduction results in nearly quantitative recovery of enzyme activity. The presence of a 410 nm absorption maximum and the decrease in fluorescence of the modified enzyme indicate the modification of tryptophan residues. At the same time, SH determinations after reduction of the modified enzyme show that the reagent has not affected the protected SH groups. Quantitative treatment of the data (Tsou, C.-L. (1962) Sci. Sin. 11, 1535 1558) shows that among the tryptophan residues modified, one is essential for its catalytic activity. The presence of substrates partially protects the modification of tryptophan residues as well as the inactivation, suggesting that the essential tryptophan residue is situated at the active site of this enzyme.     

Activity change during unfolding of bovine pancreatic ribonuclease A in guanidine

Bovine pancreatic ribonuclease A loses almost completely its activity in 2-3 M guanidine, whereas only very slight conformational changes can be detected when following its unfolding by changes in its intrinsic fluorescence at 305 nm and ultraviolet absorbance at 287 nm. Reactivation on diluting out the denaturant is a time-dependent process, indicating that the inactivation is not due to inhibition by a reversible association of the enzyme with guanidine. The kinetic method of following the substrate reaction, in the presence of the denaturant previously proposed for use in the study of rapid inactivation reactions (Tian, W.X. and Tsou, C.-L. (1982) Biochemistry 21, 1028-1032), is applied to examine the inactivation rates of this enzyme during guanidine denaturation, and these have been compared with the unfolding rates as followed by fluorescence and absorbance changes. It is shown that during the unfolding of this enzyme in guanidine, the inactivation of the enzyme occurs within the dead time of mixing in a stopped-flow apparatus and is at least several orders of magnitude faster than the unfolding reaction as detected by the optical parameters. It appears that, as in the case of creatine kinase reported previously, the active site of a small enzyme stabilized by multiple disulfide linkages, such as ribonuclease A, is also situated in a region which is much more liable to being perturbed by denaturants than is the molecule as a whole.     

1,N6-etheno-2-aza-adenosine 3',5'-monophosphate: a new fluorescent substrate for cycle nucleotide phosphodiesterase

1,N⁶-etheno-2-aza-adenosine 3′,5′-monophosphate (cyclic 2-aza-?-AMP) has been shown to be a sensitive and an efficient substrate for the assay of cyclic-nucleotide phosphodiesterase. The relative activity is 75% compared to cyclic AMP. Two K_m values of 503 and 15 μm were observed with the beef heart enzyme.