Time-frequency analysis of heart murmurs. Part II: Optimisation of time-frequency representations and performance evaluation

The basic parameters of the spectrogram, the Choi-Williams, and the Bessel distributions are adjusted to provide the best time-frequency representations (TFRs) of the simulated murmur signals of mitral stenosis, mitral regurgitation, aortic stenosis, aortic regurgitation, and of two musical murmurs. The initial adjustment of the parameters of each TFR technique is performed by computing and minimising the relative averaged absolute error between the frequency contours at −3dB and −10dB of each TFR of the simulated murmurs and those of the theoretical distribution of the same signals. The results show that the spectrogram generally provides very good to excellent performance in representing the TFRs of stenotic and regurgitant murmurs. Improvements provided by the Choi-Williams and the Bessel distributions are minor but not systematic for the two signal-to-noise ratios tested (0 and 30 dB) and for the two frequency contours estimated. The Bessel and the Choi-Williams distributions provide the best performance for the musical murmurs. The study shows that although a single technique cannot be optimal for all six murmurs, the spectrogram using a Hamming window of 30 ms is an acceptable compromise to detect the six simutated heart murmurs.     

Rectus muscle flap for repair of refractory bladder fistula following renal transplantation: a case report

We report a case of refractory bladder fistula in a diabetic renal allograft recipient that recurred shortly after conventional operative repair without any detectable external cause. After reoperation and use of a vascularized rectus muscle flap the fistula closed and the patient has retained excellent graft function. It is suggested that this technique should be considered as the primary repair modality for bladder fistulas in diabetic recipients, when wound healing is impaired seriously as a consequence of the combined effects of diabetic microangiopathy and steroid therapy.     

A method of portalizing the venous blood flow of the left adrenal gland

The authors, having studied the long-term results of the operation of creating the renoportal venous anastomoses in patients with severe and malignant course of arterial hypertension, revealed anastomotic thrombosis in presence of hypotensive effect. Developed in the experiment and employed in 7 patients was the technique of dosaged narrowing the central left adrenal vein with the aim of achieving its thrombosis, inclusion of the collateral routes of the left adrenal blood outflow into the system of the portal vein and inactivation of aldosterone in the liver.     

Injury of the rotator cuff. I. Morphological and patho-physiological basis

Authors summarize the basic features of the functional anatomy and pathogenesis of the rotator cuff tears, essential for clinical practice. On the basis of literary data and own experiences a new classification of the rotator cuff tears was elaborated that can be reliably used in operative indications.     

Surgical treatment of myasthenia gravis in children

Thymectomy was included in the complex of therapeutic measures in the management of generalized myasthenia in 41 children. Much attention was given to preoperative management in which plasmapheresis was applied along with the traditional methods. As a result, maximum compensation of the myasthenic disorders was achieved and spontaneous respiration was restored in 9 patients who were given artificial ventilation of the lungs before the operation. The authors describe the techniques of thymectomy and the changes found in the thymus during histological study. No complications occurred. All of the children were discharged from the clinic in an improved condition. The late-term results were studied in 38 children in follow-up periods of 6 months to 4 years. Marked stable improvement was recorded in 31 (77.5%) patients.     

Biochemical markers of compliance in the Physicians' Health Study

The Physicians' Health Study is a randomized, double-blind, placebo-controlled trial using a 2 x 2 factorial design to test the effects of low-dose aspirin on risk of cardiovascular disease and beta-carotene supplementation on the incidence of cancer. To evaluate self-reported compliance with assigned treatment, we measured serum thromboxane B2, which is decreased after aspirin use, and plasma beta-carotene in samples of study participants drawn from three geographic locations in three different time periods. Thromboxane B2 levels were markedly lower in those assigned to aspirin (median = 63.5 pg/mL) than in those given aspirin placebo (median = 3,600 pg/mL, P less than .0001). Similarly, those assigned to beta-carotene had significantly higher levels (median = 1,176 ng/mL) than those given placebo (median = 306 ng/mL, P less than .0001). In addition, there was a highly significant positive correlation between levels of these biochemical markers and the self-reports of compliance (r = 0.65 for thromboxane B2 and r = 0.69 for beta-carotene, P less than .0001). These findings support the validity of the self-reported compliance in the Physicians' Health Study.     

Acetabular protrusion in thalassemia. A report of four cases

Four female patients with thalassemia intermedia developed secondary acetabular protrusion. These cases could be the first reported cases of nontraumatic acetabular protrusion in patients with thalassemia. The rarified pelvic bone may be due to medullary hyperplasia, iron overload, or disordered calcium metabolism in conjunction with osteomalacia. The fact that currently patients with beta-thalassemia have a longer life expectancy may explain the recent observation of this entity, which should become more familiar to orthopedic surgeons who treat thalassemia patients in the future.     

十名志愿者口服维拉帕米缓释片药代动力学和心电图研究

对10名男性受试者单剂量po240mgVer缓释片药代动力学及心电图变化进行研究。血药浓度—时间数据用零级吸收过程的一室模型拟合,其药代动力学参数:T_max5.9±1.6h;C_max118.9±37.2μg·L^-1;T₁ 5.4±1.5h;k₀30.5±17.5μg·L^-1·h^-1;T_1/210.8±4.9h。PR间期延长有显著意义,血药浓度与PR间期变化满足S 型模型,其药效学参数:EC₅₀ 64.6±16.9μg·L^-1; E_max54±11ms;s 1.68±0.66。     

Internal and external information processing by lateral hypothalamic glucose-sensitive and insensitive neurons during bar press feeding in the monkey

Single neuron activities in the lateral hypothalamic area (LHA) were recorded during bar press feeding task in the monkey. First registered neurons were sorted into 2 groups, glucose-sensitive (GS) and glucose-insensitive (GIS) neurons, depending on their glucose sensitivity. Then firing variations to feeding, electrophoretically applied catecholamines and opiate, and to odor and taste stimuli were investigated. GS neurons responded to dopamine, noradrenaline and morphine more often than GIS neurons. In feeding task GS neurons responded during bar press (BP) and reward (RW) periods with long-lasting inhibition of firing and at cue tone (CT) with transient inhibition, while GIS neurons responded during BP and RW periods mainly with excitation and at cue light (CL) with excitation. A majority of GS neurons responded to both odor and taste stimuli more often than GIS neurons. Data suggest that these two kinds of neurons in the LHA may be involved in different functional aspects of feeding: GS neurons, mainly in internal information processing and reward mechanism, and GIS neurons, in external information processing and motor aspects.