Green tea catechins inhibit bacterial DNA gyrase by interaction with its ATP binding site

Catechins are the main ingredients of green tea extracts and have been shown to possess versatile biological activities, including antimicrobial. We determined that the catechins inhibit bacterial DNA gyrase by binding to the ATP binding site of the gyrase B subunit. In the group of four tested catechins, epigallocatechin gallate (EGCG) had the highest activity, followed by epicatechin gallate (ECG) and epigallocatechin (EGC). Specific binding to the N-terminal 24 kDa fragment of gyrase B was determined by fluorescence spectroscopy and confirmed using heteronuclear two-dimensional NMR spectroscopy of the EGCG-15N-labeled gyrase B fragment complex. Protein residues affected by binding to EGCG were identified through chemical shift perturbation. Molecular docking calculations suggest that the benzopyran ring of EGCG penetrates deeply into the active site while the galloyl moiety anchors it to the cleft through interactions with its hydroxyl groups, which explains the higher activity of EGCG and ECG.     

Laser surgery for early to moderately advanced glottic, supraglottic, and hypopharyngeal cancers

Current practice standards for the treatment of early to moderately advanced laryngeal and hypopharyngeal cancer demand both achievement of cure and preservation of laryngeal structure and function to the greatest extent possible. The oncologic and functional results of transoral laser microsurgery (TLM) for early glottic cancer appear to be comparable to those of radiotherapy, with a higher rate of laryngeal preservation and a lower cost. TLM for early and moderately advanced supraglottic and hypopharyngeal cancers offers similar results with regard to survival and local control to those obtained with open surgical approaches. In addition, functional results of TLM are superior to those of open approaches because tracheotomies are usually avoided, rehabilitation of swallowing is faster, and hospital stay is shorter. TLM, when applicable, has become the preferred modality for surgical treatment of most early to moderately advanced cancers of the larynx and selected tumors of the hypopharynx.     

A Custom Designed Chip to Control an Implantable Stimulator and Telemetry System for Control of Paralyzed Muscles

A custom designed chip has been developed for the control of paralyzed muscles. The system is capable of fulfilling the stimulus and telemetry needs of advanced functional neuromuscular stimulation (FNS) applications requiring multiple channels of stimulation and multiple channels for sensor or biopotential sensing. An inductive radiofrequency link provides power to the implant device as well as 2 way transcutaneous communication. An application specific integrated circuit (ASIC) decodes the commands and provides functional control within the implant, and modular circuitry provides specific implant functions. The ASIC chip provides up to 32 independent channels of stimulation with independent control of stimulus pulse duration, pulse amplitude, interphase delay, recharge phase duration, and pulse interval. It can also control up to 8 independent back telemetry analog channels with independent control of sampling rate and pulse powering parameters (amplitude and duration). The mixed analog digital chip has been fabricated in 1.2 microm n-well CMOS technology.     

Distance deviation measure of contouring variability

Background

Several methods that are currently used for contouring analysis have problems providing reliable and/or meaningful results. In this paper a solution to these problems is proposed in a form of a novel measure, which was developed based on requirements defined for contouring studies.

Materials and methods

The proposed distance deviation measure can be understood as an extension of the closest point measures in such a way that it does not measure only distances between points on contours but rather analyse deviation of distances to both/all contours from each image point/voxel. The obtained result is information rich, reliable and provided in a form of an image, enabling detailed topographic analysis. In addition to image representation, results can be further processed into angular representation for compact topographic analysis or into overall scalar estimates for quick assessment of contour disagreement.

Results

Distance deviation method is demonstrated on a multi observer contouring example with complex contour shapes, i.e., with pronounced extremes and void interior. The results are presented using the three proposed methods.

Conclusions

The proposed method can detect and measure contour variation irrespective of contour complexity and number of contour segments, while the obtained results are easy to interpret. It can be used in various situations, regarding the presence of reference contour or multiple test contours.     

MRI-assisted cervix cancer brachytherapy pre-planning,based on application in paracervical anaesthesia: final report

Background

Optimal applicator insertion is a precondition for the success of cervix cancer brachytherapy (BT). We aimed to assess feasibility and efficacy of MRI-assisted pre-planning, based on applicator insertion in para-cervical anaesthesia (PCA).

Patients and methods.

Five days prior to BT, the pre-planning procedure was performed in 18 cervix cancer patients: tandem-ring applicator was inserted under PCA, pelvic MRI obtained and applicator removed. Procedure tolerability was assessed. High risk clinical target volume (HR CTV) and organs at risk were delineated on the pre-planning MRI, virtual needles placed at optimal positions, and dose planning performed. At BT, insertion was carried out in subarachnoidal anaesthesia according to pre-planned geometry. Pre-planned and actual treatment parameters were compared.

Results

Pre-planning procedure was well tolerated. Median difference between the pre-planned and actual needle insertion depth and position were 2 (0–10) mm and 4 (0–30) degrees, respectively. The differences between the pre-planned and actual geometric and dosimetric parameters were statistically non-significant. All actual needles were positioned inside the HR CTV and outside the organs at risk (OAR).

Conclusions

Our pre-planning approach is well tolerated and effective. Pre-planned geometry and dose distribution can be reproduced at BT.     

Postoperative concomitant irradiation and chemotherapy with mitomycin C and bleomycin for advanced head-and-neck carcinoma

PURPOSE: In a prospective randomized clinical study, simultaneous postoperative application of irradiation (RT), mitomycin C, and bleomycin was tested in a group of patients with operable advanced head-and-neck carcinoma. It was expected that the planned combined postoperative therapy would reduce the number of locoregional recurrences and prolong survival. METHODS AND MATERIALS: A total of 114 eligible patients with Stage III or IV squamous cell head-and-neck carcinoma were randomized to receive postoperative RT alone (Group 1) or RT combined with simultaneous mitomycin C and bleomycin (Group 2). Patients were stratified according to the stage and site of the primary tumor and the presence or absence of high-risk prognostic factors. Primary surgical treatment was performed with curative intent in all patients. Patients in both groups were postoperatively irradiated to the total dose of 56-70 Gy. Chemotherapy included mitomycin C 15 mg/m(2) after 10 Gy and 5 mg of bleomycin twice a week during RT to the planned total dose of 70 mg. RESULTS: At 2 years, patients in the radiochemotherapy group had better locoregional control (86%) than those in the RT alone group (69%; p = 0.037). Disease-free survival and overall survival was also better in the radiochemotherapy group compared with the RT-alone group (76% vs. 60%, p = 0.099; and 74% vs. 64%, p = 0.036, respectively). Patients who benefited from chemotherapy were those with high-risk factors. CONCLUSION: The results of the present study indicate that concomitant postoperative radiochemotherapy with mitomycin C and bleomycin improves locoregional control and survival in patients with advanced head-and-neck carcinoma. The patients who benefited from chemotherapy were those with high-risk factors.     

Topical cardiac cooling--computer simulation of myocardial temperature changes

Topical cardiac cooling (TC) is often used in cardiac surgery. We used a computer simulation to study temperature changes in the heart, especially in the right ventricular wall. A three-dimensional computer heart model, derived from Visible Human Data set, National Library of Medicine was used. The model is made from cubes, with spatial resolution of 1mm. Explicit Finite Different method and temperature diffusion equation were used to calculate new temperatures. Three different simulations were performed and simulated temperatures were drawn on a cross-section of heart model in different colors. The results show that areas not immersed into TC solution are less protected against ischemia. It is important not to rely solely on topical cooling but use appropriate method of myocardial protection technique.