Distribution of paresthesias in Carpal Tunnel Syndrome reflects the degree of nerve damage at wrist.

OBJECTIVE: To verify whether the distribution of paresthesias in patients with Carpal Tunnel Syndrome (CTS) is related to the degree of the neurophysiological involvement. METHODS: We performed a cross-sectional study and retrospectively evaluated 163 patients who referred to our electromyography lab and to which a clinical and electrophysiological diagnosis of CTS was made. We divided the patients into two groups: (1) patients complaining of paresthesias at the hand as a whole and (2) patients with paresthesias in the territory of the median nerve. We referred to the distribution of paresthesias at the hand as GLOVE and to the distribution in the territory of the median nerve as MEDIAN. We compared the neurophysiological impairment in GLOVE and MEDIAN distributions. Moreover, we performed multiple regression analysis to evaluate which clinical-neurophysiological variables determined GLOVE and MEDIAN distribution. RESULTS: In our sample, 70.4% of patients had GLOVE distribution and 29.6% of patients MEDIAN distribution. The risk of presenting MEDIAN distribution increases about twice (OR = 2.07; 95% IC: 1.51-2.83) for each unitary increment of neurophysiological class. CONCLUSIONS: The distribution of paresthesias reflects the degree of nerve damage at wrist; patients suffering of SEV/EXT CTS present MEDIAN distribution. SIGNIFICANCE: Our data have important clinical implications because they strongly suggest that we have to consider the possibility of a severe neurophysiological involvement of the median nerve at wrist in patients complaining of MEDIAN distribution.     

Cause-specific mortality in professional flight crew and air traffic control officers: findings from two UK population-based cohorts of over 20,000 subjects

Objective  

Flight crew are exposed to several potential occupational hazards. This study compares mortality rates in UK flight crew to those in air traffic control officers (ATCOs) and the general population.     

Parametric uncertainty and disturbance attenuation in the suboptimal control of a non‐linear electrochemical process

The optimal control of the hydrogen evolution reactions is attempted for the regulation and change of set‐point problems, taking into account that model parameters are uncertain and I/O signals are corrupted by noise. Bilinear approximations are constructed, and their dimension eventually increased to meet accuracy requirements with respect to the trajectories of the original plant. The current approximate model is used to evaluate the optimal feedback through integration of the Hamiltonian equations. The initial value for the costate is found by solving a state‐dependent algebraic Riccati equation, and the resulting control is then suboptimal for the electrochemical process. The bilinear model allows for an optimal Kalman–Bucy filter application to reduce external noise. The filtered output is reprocessed through a non‐linear observer in order to obtain a state‐estimation as independent as possible from the bilinear model. Uncertainties on parameters are attenuated through an adaptive control strategy that exploits sensitivity functions in a novel fashion. The whole approach to this control problem can be applied to a fairly general class of non‐linear continuous systems subject to analogous stochastic perturbations. All calculations can be handled on‐line by standard ordinary differential equations integration software. Copyright © 2007 John Wiley & Sons, Ltd.     

Ages at Initiation of Cigarette Smoking and Quit Attempts Among Women: A Generation Effect

OBJECTIVES: This study sought to determine whether the age at initiation of regular cigarette smoking and the likelihood of quitting smoking through age 35 differ among women from younger versus older generations. METHODS: Annual population-based, random surveys (total of 3676 female residents of Geneva, Switzerland, aged 35-74 years) were conducted from 1992 to 1998. RESULTS: Women younger than 55 years were more likely to be past or current smokers, began smoking earlier (median age < 20 years), and smoked more cigarettes per day than older women, yet attempted to quit smoking more often before age 35 (log-rank P <.001). CONCLUSIONS: Young female smokers have a higher propensity to quit smoking compared with older women. Encouraging young smokers to quit-in addition to preventing nonsmokers from starting-may be an important facet of reducing cigarette smoking prevalence among adolescents.     

Feasibility of universal screening mammography. Lessons from a community intervention

It is estimated that 44,500 American women will die of breast cancer in 1991. The breast cancer screening guidelines of the American Cancer Society and the National Cancer Institute calling for annual mammography for all women older than 50 years have been endorsed by numerous professional groups. Third-party reimbursement for screening mammography is becoming more prevalent, and payment for screening mammography is now a Medicare benefit. Our studies, conducted as part of a National Cancer Institute grant to increase the routine use of screening mammography and clinical breast examination in women 50 to 75 years of age, have uncovered a number of significant barriers to the implementation of screening guidelines among women, primary care physicians, and providers of mammography services. These barriers, as well as methods to assure the quality of mammography, need to be addressed before universal screening is feasible.     

Effectiveness of telephone counseling for mammography: results from five randomized trials.

BACKGROUND: Women over age 50 continue to be underscreened for breast cancer. The purpose of this report is to compare the effectiveness of a barrier-specific telephone counseling intervention across the five study sites of the Breast Cancer Screening Consortium (BCSC). METHODS: Each of the BCSC projects was a randomized study of the effectiveness of telephone counseling (TC) in comparison to a control condition. Eligible underusers were identified and surveyed by telephone before and after the implementation of the interventions. Data from a total of 3,461 underusers were analyzed. We tested whether significantly more women randomized to TC than to control were regular mammography users at the follow-up survey. Data were analyzed separately by site. RESULTS: Overall, TC was not significantly more effective than control in encouraging regular mammography. The pooled consortium-wide odds ratio was 1.08 (95% confidence interval: 0.91 to 1.27). CONCLUSIONS: TC has the potential to support maintenance of mammogram use. Modifications are needed to maximize this potential and additional methods should be used in conjunction with TC to reach women who are underusers of mammography.     

A variable stiffness mechanism for steerable percutaneous instruments: integration in a needle

Needles are advanced tools commonly used in minimally invasive medical procedures. The accurate manoeuvrability of flexible needles through soft tissues is strongly determined by variations in tissue stiffness, which affects the needle-tissue interaction and thus causes needle deflection. This work presents a variable stiffness mechanism for percutaneous needles capable of compensating for variations in tissue stiffness and undesirable trajectory changes. It is composed of compliant segments and rigid plates alternately connected in series and longitudinally crossed by four cables. The tensioning of the cables allows the omnidirectional steering of the tip and the stiffness tuning of the needle. The mechanism was tested separately under different working conditions, demonstrating a capability to exert up to 3.6 N. Afterwards, the mechanism was integrated into a needle, and the overall device was tested in gelatine phantoms simulating the stiffness of biological tissues. The needle demonstrated the capability to vary deflection (from 11.6 to 4.4 mm) and adapt to the inhomogeneity of the phantoms (from 21 to 80 kPa) depending on the activation of the variable stiffness mechanism.

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