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1.
We have investigated the effect of methylprednisolone on the intracellular activity of erythromycin and clindamycin in vitro. An assay system was developed for the determination of intracellular activity of antibiotics against Legionella pneumophila using guinea pig resident alveolar macrophages. Erythromycin at a concentration of 0.625 mg/L (5 x MIC) and clindamycin at a concentration of 8 mg/L (MIC) inhibited the growth of a single strain of L. pneumophila in macrophages, whilst ceftizoxime at a concentration of 0.625 mg/L (5 x MIC) did not. Methylprednisolone at therapeutic concentrations did not affect the intracellular antibacterial activity of either erythromycin or clindamycin against L. pneumophila. We found no direct effect of methylprednisolone on the intracellular antibacterial activity of either erythromycin or clindamycin.  相似文献   
2.
PURPOSE: To determine whether infiltrative lung, airway, or vascular disease can be differentiated as the cause of mosaic attenuation on thin-section computed tomographic (CT) scans of the lung. MATERIALS AND METHODS: Thin-section CT scans were reviewed in 70 patients examined at three institutions. A mosaic attenuation pattern and pathologic or clinical proof of a specific type of disease were demonstrated. Causes of the mosaic pattern included infiltrative lung disease (n = 37), airway disease (n = 22), and vascular disease (n = 11). Thin-section CT findings were assessed independently by two observers blinded to clinical findings. RESULTS: The type of disease was identified correctly at CT in 58 (83%) of 70 patients by observer 1 and 57 (81%) of 70 patients by observer 2. Infiltrative lung disease was diagnosed correctly by both observers in 34 (92%) of 37 cases. Observer 1 identified 21 (95%) of 22 cases of airway disease and three (27%) of 11 cases of vascular disease. Observer 2 identified 19 (86%) of 22 cases of airway disease and four (36%) of 11 cases of vascular disease. CONCLUSION: Infiltrative lung disease and airway disease may be differentiated reliably as the cause of mosaic attenuation on lung CT scans, whereas vascular disease is often misinterpreted as infiltrative lung disease or airway disease.  相似文献   
3.
A 0.3-μm sub-10-ns ECL 4-Mb BiCMOS DRAM design is described. The results obtained are: (1) a Vcc connection limiter with a BiCMOS output circuit is chosen due to ease of design, excellent device reliability and layout area; (2) a mostly CMOS periphery with a specific bipolar use provides better performances at high speed and low power; (3) the direct sensing scheme of a single-stage MOS preamplifier combined with a bipolar main amplifier offers high speed; and (4) the strict control of MOS transistor parameters has been proven to be more important in obtaining high speed DRAMs, based on the 4-Mb design  相似文献   
4.
The AE method is an effective technique for inspecting corrosion damage of mild steel, such as tank bottom floors. However, the correlation between AE signals and corrosion behaviour for mild steel has not yet been fully clarified. In the present study, the authors considered that the corrosion regions of bottom floors become a strong acid environment by Cl, as reported in a previous study. Thus, the polarization resistance for the test pieces of mild steel was measured with an AC impedance method under a strong acid environment. It was clear that the polarization resistance indicated the corrosion rate for a test piece of mild steel in the experiments. While measuring the AE signals, the corrosion rate was monitored with a test piece. As a result, the AE signal showed good correlation with the corrosion rates of the test pieces. The corrosion behaviour of the test pieces was then discussed with the corrosion potential measured during the experiments. Furthermore, the cathode current was changed to control the generated hydrogen gas volume. The volume of the hydrogen gas generated from the cathode reaction was correlated to the AE signals.  相似文献   
5.
A 29-ns (RAS access time), 64-Mb DRAM with hierarchical array architecture has been developed. For consistent high yields and high speed, a CMOS segment driver circuit is used as a hierarchical word line scheme. To achieve high speed, precharge signal (PC) drivers for equalizing the bit lines pairs, and shared sense amplifier signal (SHR) drivers are distributed in the array. To enhance sense amplifiers speed in low array voltage, an over driven sense amplifier is adopted. A hierarchical I/O scheme with semidirect sensing switch is introduced for high speed data transfer in the I/O paths. By combining these proposed circuit techniques and 0.25-μm CMOS process technologies with phase-shift optical lithography, an experimental 64-Mb DRAM has been designed and fabricated. The memory cell size is 0.71×1.20 μm 2, and the chip size is 15.91×9.06 mm2. A typical access time under 3.3 V power supply voltage is 29 ns  相似文献   
6.
A 44-year-old man suspected of having transitional cell carcinoma (TCC) of the prostate was referred to our hospital. He had a painful semi-erect penis at his first visit. Then needle biopsy of the corpus cavernosum histologically revealed metastatic TCC. CT of the pelvis showed bilateral ureteral obstruction caused by the advanced tumor but no lymph node swelling was found. Under the diagnosis of prostatic TCC with penile metastasis, bilateral percutaneous nephrostomy followed by two courses of combination chemotherapy (IFEP regimen) was carried out, which resulted in the disappearance of priapism. Radical cystectomy with total penectomy was performed. The final pathological diagnosis was corrected to TCC of the urinary bladder with invasion to the prostate and metastasis of the corpus cavernosum and the right obturator lymph node. Enlargement of the prostate proved to be caused by glandular hyperplasia with atypical hyperplasia of the prostate gland. Three courses of adjvent IFEP chemotherapy was given post-operatively and he has been alive with no evidence of the disease for 10 months.  相似文献   
7.
The Simple and Patlak models for estimating myocardial blood flow with 13N-ammonia have become attractive for clinical applications with PET because of their simplicity and ease of implementation. However, these models are sensitive to factors such as the data acquisition times and data integration times, which can cause errors in the estimation of myocardial blood flow, as demonstrated in this study. Limiting the application of these models to specific conditions can minimize the errors. METHODS: Dynamic PET images of the uptake of 13N-ammonia in the heart were obtained in seven humans under rest and dipyridamole stress. Myocardial blood flow was estimated using the Simple and Patlak models for different data acquisition times and data integration times. Blood flow values were compared to flow values computed with the two-compartment model as a reference. RESULTS: Blood flow values calculated with the Simple and Patlak models during the first 2 min of data acquisition were closely correlated to the two-compartment model values. Longer acquisition times resulted in significant underestimation of blood flow for the Simple model. Long integration times of greater than 60 sec also resulted in significant underestimation of blood flow for both models. CONCLUSION: The Simple and Patlak models produce estimates of myocardial blood flow that are well correlated with the two-compartment model estimated blood flows for the integration time of 60 sec from 60 to 120 sec postinjection. Because of the errors associated with longer data acquisition times and longer integration times, use of these models should be limited to a well-documented data acquisition paradigm.  相似文献   
8.
A temperature-compensation circuit technique for a dynamic random-access memory (DRAM) with an on-chip voltage limiter is evaluated using a 1-Mb BiCMOS DRAM. It was found that a BiCMOS bandgap reference generator scheme yields an internal voltage immune from temperature and Vcc variation. Also, bipolar-transistor-oriented memory circuits, such as a static BiCMOS word driver, improve delay time at high temperatures. Furthermore, the BiCMOS driver proves to have better temperature characteristics than the CMOS driver. Finally, a 1-Mb BiCMOS DRAM using the proposed technique was found to have better temperature characteristics than the 1-Mb CMOS DRAM which uses similar techniques, as was expected. Thus, BiCMOS DRAMs have improved access time at high temperatures compared with CMOS DRAMs  相似文献   
9.
A high-resolution PET system for small animals was tested for its applicability to the investigation of regional myocardial blood flow (MBF) in rabbits. METHODS: Nineteen measurements were performed in 10 closed-chest anesthetized rabbits at baseline and during infusions of adenosine (0.2 mg/kg/min) and propranolol (0.20-1.20 mg slow infusion) to obtain a wide range of MBF. Myocardial blood flow was assessed both by dynamic 13N-ammonia PET and by colored microspheres. Blood was withdrawn directly from the femoral artery, and arterial 13N activity was measured by coincidence type gamma detection system for the input function. Nitrogen-13 myocardial uptake was calculated by dividing the myocardial 13N activity by the integral value of the input function. RESULTS: Three or four contiguous cross-sectional myocardial images were obtained after 13N-ammonia injection. The left ventricular wall and cardiac cavity were clearly visualized. Moreover, initial passage of the tracer through the heart was obtained with serial 10-sec PET images. Nitrogen-13 myocardial uptake correlated well with flow measured with microspheres (r = 0.88). CONCLUSION: Our cardiac PET system can be used for in vivo imaging and quantitation of MBF in small animals and may play an important role in the future study of animal models of cardiovascular diseases.  相似文献   
10.
N-glycosylation allows newly synthesized glycoproteins to interact with a lectin-based chaperone system in the endoplasmic reticulum. Binding to the lectins calnexin and calreticulin is mediated by monoglucosylated oligosaccharides that are produced transiently by the deglucosylation and reglucosylation of substrate glycoproteins during their maturation process. In mammalian cells, calnexin, calreticulin and associated factors promote the correct folding and oligomerization of many glycoproteins, providing unique quality control and chaperone functions specific for glycoproteins in the endoplasmic reticulum.  相似文献   
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