Jones matrix for round-trip wave propagation in nonreciprocal media

Using a communication channel model, we prove the known theorem that the Jones matrix of a system for backward propagation is the transpose of that for forward propagation. This result, together with the transformation of a coordinate system for opposite propagation directions, is shown to be useful for analyzing the round-trip wave propagation in nonreciprocal media.

Binary encoding of gray-scale nonlinearly transformed filters for optical pattern recognition

A binary-encoded nonlinear matched filter for optical correlation is described. The gray-scale matchedfilter function, transformed by a general type of nonlinearity, is represented in a binary format by a threshold function that changes as a function of the spatial frequency. The output correlation term of the binary-encoded filter is equivalent to the output correlation term of the gray-scale nonlinear matched filter.

Sensitivity of the nonlinear joint transform correlator: experimental investigations

Experiments are provided to investigate nonlinear joint transform correlator sensitivity to scaling and rotation changes of input objects for various degrees of nonlinearity applied to the joint power spectrum. The experimental results for the images used here show that a severe nonlinear transformation of the joint power spectrum increases the sensitivity of the correlation peak intensity to scaling and rotation changes of input objects. However, the correlation peak-to-sidelobe ratio of the nonlinear joint transform correlator remains higher than the linear joint transform correlator. These experiments indicate that, in the presence of input signal rotation or scale changes, the performance of the nonlinear joint transform correlator may be better than the linear joint transform correlator. The effect of the modulation transfer function of the spatial light modulator on the nonlinear joint transform correlator performance in the presence of multiple input targets is discussed.

Multiple-object binary joint transform correlation using multiple-level threshold crossing

We investigate the performance of the binary joint transform correlator (JTC) in the presence of multiple objects for two types of thresholding that are used to binarize the joint power spectrum. The first method uses the median of the joint power spectrum of the reference image and the input scene as the threshold value. The second method is a two-dimensional thresholding technique used to maximize the light intensity of the correlation peak, and it eliminates the even-order harmonic terms. The correlation performance of the binary JTC is determined for both thresholding methods. The binary JTC output is determined analytically in terms of multiple input targets. The separation requirements of the binary JTC and the conventional JTC in the presence of multiple targets are computed. Computer simulation and experiments are presented for a limited number of multiple-target images to determine the correlation peak-to-sidelobe ratio and the correlation width for both thresholding techniques. In the experiments, a hybrid optical processor with an optically addressed spatial light modulator is used to implement the binary JTC. The results indicate that, using both thresholding methods, the binary JTC produces a large peak-to-sidelobe ratio and a narrow peak for the multiple-target images used in the tests. The two-dimensional threshold function produces better correlation performance compared with the median thresholding.

Experiments on nonlinear joint transform correlator using an optically addressed spatial light modulator in the Fourier plane

Correlation experiments for the images used in the proposed setup indicate that nonlinear compression of the joint power spectrum may be necessary to produce good correlation performance and a peak-to-sidelobe ratio of larger than unity.

Binary encoding of gray scale nonlinear joint transform correlators

A nonlinear joint transform correlator is described where the joint power spectrum, transformed by various degrees of nonlinearity, is represented in a binary format using a multiple level threshold function.

Induction of 8-hydroxydeoxyguanosine but not initiation of carcinogenesis by redox enzyme modulations with or without menadione in rat liver

Inducibility of oxidative stress in rat liver in vivo by menadione-associated redox cycling activation under redox enzyme modulating conditions was examined by monitoring hepatocyte injury and 8-hydroxydeoxyguanosine (8-OHdG) levels of liver DNA. In addition, the treatment-associated liver tumor initiating activity was assessed in terms of development of gamma-glutamyl-transpeptidase (GGT)- and glutathione S-transferase placental form (GST-P)-positive foci and hyperplastic nodules. With or without following menadione treatment (50 mg/kg, i.g.), redox enzyme modulations of increased cytochrome P450 reductase activity induced by phenobarbital (PB)-Na (100 mg/kg, i.p. for 5 days), inhibition of DT-diaphorase by dicumarol (25 mg/kg, i.p.) and depletion of glutathione by phorone (200 mg/kg, i.p.), with or without further supplement of iron EDTA-Na-Fe(III) (70 mg/kg, i.p.), caused both substantial hepatocyte necrosis and 8-OHdG production in Fischer 344 male rats. Subsequent feeding with a 0.05% PB diet for 64 weeks resulted in slightly increased development of GGT-positive foci but not GST-P positive lesions or hyperplastic nodules, suggesting a lack of tumor-initiating activity of the oxidative DNA damage associated with redox enzyme modulations with or without menadione.

[Prevention and treatment of emphysema in the guinea pig with ligustrazine]

This study demonstrated that ligustrazine possesses inhibitory effect obviously on elastic enzyme in vitro, and it can be used to prevent and treat emphysema instead of serum. Using light microscope and electron microscope, the authors observed morphological indexes and analyzed the indexes with stereology and statistics in lung tissues of guinea pigs. The results showed that there was no obvious difference between the ligustrazine administration group and the saline control group as pathological changes were not found in the ligustrazine administration group under microscope. The shapes of elastic proteins were the same under electron microscope observation. Aerosol inhalational method induced emphysema model of elastic enzyme in guinea pig could be improved with ligustrazine treatment.

Catecholamine induced cardiac hypertrophy

Cardiac hypertrophy was induced in adult female Wistar rats by daily subcutaneous injections of isoproterenol (0.3 mg/kg body weight). Heart weight increased 39% after eight days of treatment. Left ventricular pressure development (positive dP/dt) in hearts four days after hypertrophy induction was significantly increased, while negative dP/dt remained unchanged. RNA polymerase activity in isolated myocyte and nonmyocyte nuclei was stimulated 29 and 23%, respectively 24 h after a single isoproterenol injection. In the myocyte fraction, RNA polymerase activation progressively increased up to four days of treatment and then returned to control values after eight days. In the nonmyocyte nuclear subset, RNA polymerase activity showed no further stimulation and gradually returned to control values after eight days of treatment. Chromatin template function was substantially stimulated in the early stage (one to four days) of hypertrophy in both myocyte and nonmyocyte fractions. Titration of chromatin against a fixed amount of RNA polymerase (5 micrograms) in the presence of rifampicin and heparin showed that less chromatin from hypertrophied hearts was required to saturate the enzyme. These results indicate that both myocyte and nonmyocte chromatin from hypertrophied hearts can support greater enzyme binding than normal chromatin. The alkaline sucrose density centrifugation profile of DNA in myocyte and nonmyocyte chromatin from day 4 hypertrophied hearts was less fragmented. These observations suggest that during the early phase of isoproterenol-induced cardiac hypertrophy, enhanced RNA polymerase activity and chromatin template function play a coordinated role in RNA synthesis. The increased template activity could be due to alterations in chromatin composition which was indicated by the change in their enzyme binding capacity and DNA fragmentation profile.

Myocyte and nonmyocyte RNA polymerase activity and chromatin template function

Myocardial and nonmyocardial cell nuclei were isolated from ventricles of adult male Wistar rats by means of sucrose density centrifugation. RNA polymerase activity in myocyte nuclei was approximately 80-90% higher than in nonmyocytes. Total myocyte chromatin template activity using Escherichia coli RNA polymerase was linear and about onefold greater than the nonmyocyte fraction over a fivefold range of chromatin concentrations. Preincubation time required for RNA polymerase to form a stable binding complex with chromatin was at least 40 min for myocyte and 30 min for nonmyocyte nuclear subsets. Titration of chromatin against a fixed amount of RNA polymerase (5 micrograms) showed that 5 micrograms of myocyte chromatin (as DNA) and 8 micrograms of nonmyocyte chromatin (as DNA), respectively, were required to saturate the enzyme. These results indicate that myocyte chromatin can support greater enzyme binding than can nonmyocyte chromatin. The distribution of DNA fragments from isolated myocyte and nonmyocyte nuclei were similar when alkaline sucrose density centrifugation was used. Chromatin prepared from these nuclear subsets showed no difference in degree of DNA fragmentation. These observations indicate that compared with nonmuscle cells, myocytes from adult rat hearts have higher RNA polymerase activity, greater overall chromatin template function, and higher binding capacity for RNA polymerase. Collectively, these data suggest that adult cardiac muscle cells should have a larger potential for RNA synthesis than nonmuscle cells.

Protein synthesis in compensatory hypertrophy of rat plantaris

Protein synthesis in rat plantaris muscle undergoing surgically induced hypertrophy was studied using a perfused hindquarter preparation. The tissue mass of the hypertrophied muscle increased 11, 33, 33, and 104% at 2, 5, 15, and 50 days postsurgery. Total tissue protein synthesis was unchanged during the early phase but was significantly elevated after 15 and 50 days of work overload. Myosin synthesis was also significantly elevated after 15 and 50 days of hypertrophic growth. Increases in muscle protein content (milligrams per muscle) for each protein fraction examined were temporally in step with the altered synthetic rates. The shift in muscle fibre-type profile from approximately 10% alkaline-labile fibres in the control muscle to about 25% alkaline-labile fibres in the hypertrophied muscle also followed a similar time course. These data suggest that during compensatory hypertrophy, enhanced protein synthesis may be the dominant mechanism for the massive accumulation of muscle protein. However, its contribution to muscle growth does not become evident until about 15 days after the initial growth stimulus.

Regression of isoproterenol-induced cardiac hypertrophy

Cardiac hypertrophy was induced in adult female Wistar rats after 8 days of daily subcutaneous injections of isoproterenol (ISO). Regression from hypertrophy was studied following 1, 2, 4, 8, 12, and 20 days of ISO withdrawal. After 8 days of treatment cardiac mass increased 40%. Following ISO withdrawal, ventricular regression occurred during the first 8 days. After 12-20 days of recovery, a new steady-state heart weight to body weight ratio was established that was 12-13% above the controls. The half-time recovery for heart weight was 3.8 days. Ventricular RNA content was stimulated 76% after 8 days of ISO-induced hypertrophy. During regression RNA content decreased rapidly during the first 8 days with a half-time of 3.4 days. Following 20 days of recovery ventricular RNA was still 31% above the controls. However, myocyte RNA was stimulated 86% following 8 days of ISO treatment and returned to control level after 12 days of regression. Myocardial DNA was increased 23% in the hypertrophied hearts and did not change during the recovery period. Hydroxyproline was increased in the ISO-treated hearts and decreased only slightly during the recovery interval. These data indicate that ISO-induced hypertrophy was reversible while ventricular RNA content only partially recovered. Nevertheless, myocyte RNA showed a large stimulation that was completely reversible at least after 12 days of recovery.

Development of isoproterenol-induced cardiac hypertrophy

The development of cardiac hypertrophy was studied in adult female Wistar rats following daily subcutaneous injections of isoproterenol (ISO) (0.3 mg/kg body weight). A time course was established for the change in tissue mass, RNA and DNA content, as well as hydroxyproline content. Heart weight increased 44% after 8 days of treatment with a half time of 3.4 days. Ventricular RNA content was elevated 26% after 24 h of a single injection and reached a maximal level following 8 days of therapy. The half time for RNA accumulation was 2.0 days. The total content of hydroxyproline remained stable during the first 2 days of treatment but increased 46% after 4 days of therapy. Ventricular DNA content was unchanged during the early stage (1-4 days) of hypertrophic growth but increased to a new steady-state level 19% above the controls after 8 days of treatment. Intraventricular pressures and coronary flow measures were similar for control and experimental animals following 4 days of developed hypertrophy. However, dP/dt in the ISO-treated hearts was slightly but significantly (P less than 0.05) elevated. These data indicate that the adaptive response to ISO shows an early hypertrophic phase (1-4 days) characterized by a substantial increase in RNA content and cardiac mass in the absence of changes in DNA. However, prolonged stimulation (8-12 days) appears to represent a complex integration of both cellular hypertrophy and hyperplasia within the heart.