Optogenetic stimulation of the cochlear nucleus using channelrhodopsin-2 evokes activity in the central auditory pathways

Optogenetics has become an important research tool and is being considered as the basis for several neural prostheses. However, few studies have applied optogenetics to the auditory brainstem. This study explored whether optical activation of the cochlear nucleus (CN) elicited responses in neurons in higher centers of the auditory pathway and whether it elicited an evoked response. Viral-mediated gene transfer was used to express channelrhodopsin-2 (ChR2) in the mouse CN. Blue light was delivered via an optical fiber placed near the surface of the infected CN and recordings were made in higher-level centers. Optical stimulation evoked excitatory multiunit spiking activity throughout the tonotopic axis of the central nucleus of the inferior colliculus (IC) and the auditory cortex (Actx). The pattern and magnitude of IC activity elicited by optical stimulation was comparable to that obtained with a 50 dB SPL acoustic click. This broad pattern of activity was consistent with histological confirmation of green fluorescent protein (GFP) label of cell bodies and axons throughout the CN. Increasing pulse rates up to 320 Hz did not significantly affect threshold or bandwidth of the IC responses, but rates higher than 50 Hz resulted in desynchronized activity. Optical stimulation also evoked an auditory brainstem response, which had a simpler waveform than the response to acoustic stimulation. Control cases showed no responses to optical stimulation. These data suggest that optogenetic control of central auditory neurons is feasible, but opsins with faster channel kinetics may be necessary to convey information at rates typical of many auditory signals

Waiting time for treatment of women with breast cancer in Podlaskie Voivodeship (Poland) in view of place of residence. A population study

Introduction: Treatment delay is a major problem of contemporary oncology. Knowing the time interval between diagnosis and initiation of treatment, together with monitoring this adverse prognostic factor, is an important element of the treatment planning process in the population and can contribute to the improvement of patients’ curability. Objective: To assess the waiting time for first treatment of women diagnosed with breast cancer in 2001-2002 in Podlaskie Voivodeship. Materials and methods: During 2001-2002, there were 709 cases of women with breast cancer who reported to the Voivodeship Cancer Registry in Bialystok. 659 women were diagnosed with a primary invasive breast tumour. A cohort of 499 women who were treated with a curative intent was selected from this group. The waiting time in the created cohort was calculated as the number of days between the date of the breast cancer diagnosis and date of the first treatment. Results: The average time between the date of diagnosis and date of the first treatment was 38 days. The median was 14 days. 28.6% of patients from the selected cohort waited longer than 28 days. The treatment of rural women was initiated faster than the treatment of urban patients

Investigation of the Intervertebral Disc and Fused Joint Dynamics Through Experimental Modal Analysis and the Receptance Coupling Method

Identification of intervertebral disc (IVD) dynamics is important in understanding the spine mechanism and behavior. This paper experimentally identifies the dynamics of the bovine caudal IVD using experimental modal analysis and the inverse receptance coupling method. Experimental modal analysis was performed on free-free mounted bovine caudal vertebrae joined by an IVD and a fused IVD joint. Shear, rotational, and axial dynamics of the joints are identified by curve fitting of the frequency response functions, and identifying the damping ratio, stiffness, and modal frequency in each axis. The identified dynamics are compared with the IVD joints with and without fusion. Results provide important insight into IVD dynamics and fused IVD dynamics. This method can be extended to identify human IVD joint dynamics.</jats:p

The breast-conserving surgery of women with breast cancer in Podlaskie voivodship (Poland). Population study

Introduction. The results of breast cancer treatment depend mainly on better detection in mammography screening and, consequently, a higher proportion of women with early stage of the disease. They depend also on a better access to health care services and the effectiveness of oncological treatment. One of the methods of breast cancer control is a breastconserving surgery. With a proper patients’ classification for the treatment, the results of the breast-conserving surgery do not differ in relation to mastectomy. That’s why, the availability of breast-conserving surgical methods is particularly important, especially in a population in which a population screening is conducted. Objective. The analysis of the selected aspects of the breast cancer treatment’s standard in Podlaskie Voivodeship. Patients and methods. In years 2001–2002, 709 cases of women with breast cancer were reported to the Voivodeship Cancer Registry in Bialystok. 659 women were diagnosed with a primary invasive breast cancer. Based on a cohort of 499 women treated with radical methods the following indicators, recommended by WHO for the evaluation of the breastconserving surgery’s availability, were calculated: a percentage of patients with whom breast-conserving surgery was used, a proportion of breast cancer cases receiving post-operative breast radiotherapy after breast-conserving surgery and a proportion of breast-conserving surgery in pT1 cases. Results. The breast-conserving surgery has been used much less frequently in Podlaskie Voivodeship than in Western Europe, but more frequently than in Poland in general. Conclusion. It should be aimed to provide a surgical treatment with the use of breast-conserving surgical methods to the highest possible percentage of patients. The increase of the percentage of patients treated with breast-conserving surgery methods can be a result of an effective screening realisation

Differences in results of breast cancer curative treatment between urban/rural female population in Podlaskie Voivodship of Poland before introduction of the National Cancer Control Programme

The aim of the study was to evaluate differences in the results of the curative treatment received by women with breast cancer in urban and rural area in Podlaskie Voivodship in 2001-2002 before the introduction of the National Cancer Control Programme. The analysis was based on 449 women with breast cancer, who received curative treatment in years 2001-2002. Relative 5-year survival rates as function of age and stage among urban and rural women population were calculated. The results showed that survival rates in Podlaskie Voivodship among curatively treated women with breast cancer were 81.9% but they differed between urban and rural areas. Patients living in rural areas had much lower survivals than those living in urban areas at local and regional stage of disease. In all age groups considered in the study survivals in rural areas were lower than in urban ones in which survivals were higher in 55-64 age group. These results indicated the necessity intervention in order to increase the access to the health care system and effectiveness of early detection and also improved treatment standards for more disadvantaged rural areas. These results should be also considered in monitoring of the National Cancer Control Programme introduction in Poland in 2006