Characterization of halotolerant rhizobia isolated from root nodules of Canavalia rosea from seaside areas

Twelve nodule isolates from Canavalia rosea, an indigenous leguminous halophyte growing in the seaside areas of southern Taiwan, were effective symbionts for the original host and able to grow at NaCl concentrations up to 3-3.5% (w/v). The taxonomy of these isolates was investigated using a polyphasic approach, including phenotypic characteristics, banding patterns of total proteins from sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), genomic fingerprint patterns from random amplified polymorphic DNA (RAPD) analysis, pulsed-field gel electrophoresis (PFGE) analysis, amplified 16S rDNA restriction analysis (ARDRA), 16S rRNA gene sequencing, and nifH gene sequencing. Based on the SDS-PAGE, RAPD, PFGE and ARDRA results, the 12 isolates are highly diverse. The 16S rRNA and nifH gene sequences were determined for isolates with distinct ARDRA patterns and compared with other members of the rhizobial species. We propose these isolates should be classified into the genus Sinorhizobium and distinguished from the current species of this genus.

Tai Chi Chuan to improve muscular strength and endurance in elderly individuals: a pilot study

OBJECTIVE

To evaluate the training effect of a Tai Chi Chuan (TCC) program on knee extensor muscular strength and endurance in elderly individuals.

DESIGN

Before-after trial.

SETTING

Community setting.

PARTICIPANTS

Forty-one community dwelling subjects aged 61.1 +/- 9.8 years undertook a TCC program. Nine dropped out during the study. Pretraining and posttraining measurements were obtained from 15 men and 17 women.

INTERVENTION

Subjects participated in a 6-month TCC program. Each session consisted of 20 minutes of warm-up, 24 minutes of structured TCC training, and 10 minutes of cool-down exercises.

MAIN OUTCOME MEASURES

Peak torque of dominant and nondominant knee extensors was tested at speeds of 60 degrees , 180 degrees , and 240 degrees/sec concentrically and eccentrically. Muscular endurance of the knee extensor was tested at the speed of 180 degrees /sec.

RESULTS

In the group of men, concentric knee extensor peak torque increased by 15.1% to 20.0% and eccentric peak torque increased by 15.1% to 23.7%. The group of women also showed increases, ranging from 13.5% to 21.8% in concentric peak torque, and 18.3% to 23.8% in eccentric peak torque. In addition, the knee extensor endurance ratio increased by 9.6% to 18.8% in the men and 10.1% to 14.6% in the women.

CONCLUSION

TCC training may enhance muscular strength and endurance of knee extensors in elderly individuals.

L-arginine during long-term ischemia: effects on cardiac function, energetic metabolism and endothelial damage

BACKGROUND

We have evaluated the addition of L-arginine, a precursor of nitric oxide, to a cardioplegic solution (named CRMBM) designed for long-term heart preservation.

METHODS

Isolated isovolumic-perfused rat hearts (n = 22) were arrested with the CRMBM solution either with (Arg) or without L-arginine (2 mmol/L) (Arg group, n = 12, vs control group n = 10), submitted to 8 hours of cold storage (4 degrees C) in the solution, and then reperfused for 60 minutes at 37 degrees C. In 11 hearts, we evaluated the quality of cardiac preservation with P-31 magnetic resonance spectroscopy and the measure of function and cellular integrity. Endothelium-dependent and independent vasodilatations were measured in 11 other hearts, using 5-hydroxytryptamine and papaverine to assess endothelial and smooth muscle function.

RESULTS

Adding L-arginine to the cardioplegic solution improved functional recovery during reflow, as shown by the rate pressure product (31% +/- 3% for control vs 47% +/- 3% for Arg, p = 0.003) together with higher coronary flow and diminished contracture. Purine release in coronary effluents during reperfusion was lower in the Arg group. During ischemia and reflow kinetics of intracellular pH and high-energy phosphates were similar in both groups. Coronary endothelium-dependent vasodilatation was similarly impaired in both groups, but smooth muscle was less altered with L-arginine.

CONCLUSIONS

As an additive to the CRMBM cardioplegic solution, L-arginine provides a protective effect for long-term heart preservation. Our data do not show coronary endothelial protection as the prominent mechanism.

Dietary fish oil promotes positive inotropy of ouabain in the rat heart

We tested the hypothesis that a fish oil (FO) diet promotes positive inotropy of ouabain without increased toxicity. For 2 mo, two groups of adult male rats were fed 1) a regular food diet supplemented with dietary long-chain polyunsaturated fatty acid from FO or 2) a regular food diet (control). The responsiveness to ouabain was evaluated for the two groups in Langendorff-perfused hearts, by (31)P nuclear magnetic resonance spectroscopy, and on purified membrane-bound Na-K-ATPase. The maximum positive inotropy achieved with ouabain was nearly two times higher in the FO than in the control group and was not associated with significant changes in energetics. Alteration of function and energetic metabolism and inhibition of Na-K-ATPase in response to 3 x 10(-4) M ouabain were delayed in the FO group. This study demonstrates that dietary FO, by a cardiac membrane incorporation of n-3 polyunsaturated fatty acid, promotes positive inotropy of ouabain without toxicity and changes in cardiac metabolism.

Optimized cardiac graft preservation: a comparative experimental study using P-31 magnetic resonance spectroscopy and biochemical analyses

BACKGROUND

The University of Wisconsin (UW), St. Thomas (ST) and Broussais (B) solutions were compared to the CRMBM solution, that we developed for long term heart preservation.

METHODS

Isolated isovolumic rat hearts were arrested with each cardioplegic solution (n = 5) to 8 hearts in each group), submitted to 12 hours of cold storage (4 degrees C) in the same solution and then reperfused for 60 minutes at 37 degrees C. Function was measured during control and reflow. High energy phosphates and intracellular pH were monitored by P-31 magnetic resonance spectroscopy. Analyses were performed by biochemical assays and HPLC in coronary effluents (CK, Pi, lactate, purines) and in freeze-clamped hearts (amino acids, nucleotides, CK, LDH) at the end of reperfusion.

RESULTS

Functional recovery was significantly improved with the new cardioplegic solution (50+/-12% recovery for the rate pressure product at the end of reflow vs 8+/-3% with UW, 0% with B and with ST). This result was correlated with the best metabolic and cellular protection as assessed in particular by higher PCr levels during reflow (30+/-3% vs 10+/-3% with UW, 8+/-4% with B, and 7+/-1% with ST) as well as reduced creatine kinase leakage during reflow (110+/-15 IU/60 minute vs 270 +/- 57 IU/60 minute with UW, 323+/-36 IU/60 minute with Broussais solution and 237+/-18 IU/60 minute with ST).

CONCLUSION

This new solution is more effective in prolonged myocardial protection than the three most widely used solutions.

Metabolic and functional effects of low-potassium cardioplegic solutions for long-term heart preservation

Cardioplegic solutions used to arrest the heart during open heart surgery and cardiac transplantation are based on potassium as a cardioplegic agent in a concentration range of 15-35 mM. However, high to moderate K+ concentrations increase Ca2+ influx and impair endothelial function. We have therefore evaluated the possible advantage of a lower potassium concentration in a new cardioplegic solution (named CRMBM solution) designed for long-term heart preservation. Nine isolated perfused rat hearts were submitted to 8 h of hypothermic ischemia after cardioplegic arrest, followed by 60 min of reflow at 37 degrees C. Two cardioplegic solutions were compared: (1) the CRMBM solution with 10 mM potassium (K-10 group), and (2) the CRMBM solution with 4 mM potassium (K-4 group). The quality of heart preservation was assessed by a metabolic study using P-31 magnetic resonance spectroscopy (energy metabolism and intracellular pH) combined to a functional evaluation and a measure of cellular integrity (biochemical assays in effluents and tissues). Decreasing the potassium concentration to 4 mM improved heart preservation, as shown by a higher functional post-ischemic recovery represented by the rate pressure product and a better preservation of cellular integrity. The evolutions of intracellular pH and high energy phosphate levels during ischemia and reflow were similar in both groups.

The effect of Tai Chi on cardiorespiratory function in patients with coronary artery bypass surgery

PURPOSE

This study prospectively evaluated the training effect of a 1-yr Tai Chi Chuan (TCC) program for low-risk patients with coronary artery bypass surgery (CABS) after a postoperative outpatient (phase II) cardiac rehabilitation program.

METHODS

Twenty patients with mean age of 56.5+/-7.4 yr completed this study. The TCC group included nine men who practiced classical Yang TCC with an exercise intensity of 48-57% heart rate range (HRR). The control group included 11 men whom were recommended to do a home-based self-adjusted exercise program with similar intensity of phase II cardiac rehabilitation. Graded exercise tests were performed before and after 1 yr of training for all subjects.

RESULTS

Mean attendance of the TCC group was 3.8+/-1.5 times weekly in contrast to 1.7+/-1.1 times for the control group. During the follow-up examination, the TCC group increased 10.3% in VO2peak (from 26.2+/-4.4 to 28.9+/-5.0 mL x kg(-1) min(-1), P<0.01) and increased 11.9% in peak work rate (from 135+/-26 W to 151+/-28 W, P<0.01). However, the control group showed slight decrease in VO2peak from 26.0+/-3.9 to 25.6+/-4.6 mL x kg(-1) x min(-1) and in peak work rate from 131+/-23 W to 128+/-32 W. At the ventilatory threshold, the TCC group also showed significant increase in VO2 and work rate (P<0.05). The control group did not significantly change in these variables.

CONCLUSIONS

The study demonstrated that a 1-yr TCC program for low-risk patients with CABS could favorably enhance cardiorespiratory function.

Cardiorespiratory response of heart transplantation recipients to exercise in the early postoperative period

In this study, we evaluated the cardiorespiratory function of orthotopic heart transplantation (OHT) recipients during exercise. Seventeen male OHT recipients, ranging in age from 22 to 60 years, participated in this study 47 +/- 21 days after surgery. The control group consisted of 17 sedentary healthy men. Breath-by-breath measurement of cardiorespiratory function was obtained during the incremental exercise of leg cycling. At peak exercise, the oxygen (O2) uptake (16.5 +/- 3.3 vs 33.9 +/- 8.2 mL.kg-1.min-1), work rate (82 +/- 19 vs 169 +/- 42 watts), heart rate (HR), O2 pulse, and blood lactate level of the OHT recipients were significantly lower than the respective values of the control group. At the ventilatory threshold, the OHT group also showed a significantly lower O2 uptake (10.7 +/- 1.6 vs 18.3 +/- 5.1 mL.kg-1.min-1), work rate (39 +/- 12 vs 89 +/- 33 watts), HR, O2 pulse, ventilatory equivalent for O2, and ventilatory equivalent for carbon dioxide. The OHT recipients showed a high resting HR (97 +/- 7 beats/min) and a low peak HR (123 +/- 14 beats/min) during exercise, and their HR continued to increase for 1 to 3 minutes after cessation of exercise. Our data revealed a low level of cardiorespiratory endurance in OHT recipients during the early postoperative stage. A multidisciplinary cardiac rehabilitation program should be considered to enhance physical functional capacity and quality of life, and promote return to work.

Normal standards for cardiopulmonary responses to exercise using a cycle ergometer test

The purpose of the study was to establish standards for cardiopulmonary responses to exercise in healthy Chinese subjects in Taiwan. One hundred and five sedentary healthy subjects, 55 men and 50 women aged between 20 and 75 years, were tested. They pedalled a cycle ergometer with the work rate increased by 10 W every minute until they were exhausted. Expiratory gas volume, oxygen concentration, carbon dioxide concentration, and heart rate were measured during the exercise test. Work rate (WRmax), oxygen consumption (VO2max), oxygen consumption divided by body weight (VO2max/BW), heart rate (HRmax), and ventilation (VEmax) at maximal exercise, and oxygen consumption at anaerobic threshold (VO2AT) were determined. These parameters were regressed by age (A, in year), height (H, in cm), body weight (G, in kg), and gender (S, 0 = women, and 1 = men), and the following predictive equations were obtained: 1) WRmax (W) = -1.2 A + 1.1 H + 0.7 G + 28 S - 56, R = 0.90; 2) VO2max (ml/min) = -20 A + 9.5 H + 16 G + 461 S - 237, R = 0.90; (3) VO2max/BW (ml/kg/min) = -0.31 A + 0.14 H - 0.14 G - 7.2 S + 22, R = 0.87; 4) HRmax (beat/min) = -0.81 A + 209, R = 0.61; 5) VEmax (L/min) = -0.74 A - 0.04 H + 0.93 G + 22.2 S + 42, R = 0.83; 6) VO2AT (ml/min) = -9.5 A + 3.5 H + 9.4 G + 140 S - 122, R = 0.79. Our results provide normal standards for cardiopulmonary responses to exercise during cycle ergometer testing in Taiwan.

12-month Tai Chi training in the elderly: its effect on health fitness

PURPOSE

The objective of this study was to evaluate the effect of Tai Chi Chuan (TCC) on health fitness in older individuals.

METHODS

Thirty-eight community-dwelling persons aged 58 to 70 yr completed this study. The TCC group included 9 men and 11 women; the control group included 9 men and 9 women. The TCC group practiced TCC for 11.2+/-1.4 months, with the attendance of 4.6+/-1.3 times x wk(-1). Each session included 20 min of warm-up, 24 min of TCC practice, and 10 min of cooldown. The exercise intensity was 52-63% of the heart rate range. Cardiorespiratory function, strength, flexibility, and percent of body fat were evaluated before and at the end of this study.

RESULTS

The male TCC group showed 16.1% increase in VO2max (P < 0.01), 11 degrees increase in thoracic/lumbar flexibility (P < 0.05), 18.1% increase in muscle strength of knee extensor (P < 0.01), and 15.4% increase of knee flexor (P < 0.05). The female TCC group showed 21.3% increase in VO2max (P < 0.01), 8.8 degrees increase in flexibility (P < 0.05), 20.3% increase in muscle strength of knee extensor (P < 0.05), and 15.9% increase of knee flexor (P < 0.05). The control group showed no significant change in these variables.

CONCLUSIONS

The results indicate that a 12-month Tai Chi Chuan program is effective for improving health fitness of the elderly.

Cardiorespiratory function, flexibility, and body composition among geriatric Tai Chi Chuan practitioners

OBJECTIVE

To evaluate the health-related fitness of geriatric Tai Chi Chuan (TCC) practitioners.

DESIGN

Case-control study of a TCC group and a group of sedentary controls.

SETTING

Research project at a hospital-based exercise physiology laboratory.

PARTICIPANTS

Seventy-six community-dwelling senior persons (mean age 69.3 +/- 3.9 yr), a TCC group that included 22 men and 19 women and a control group of sedentary subjects that included 18 men and 17 women with matched age and body size.

INTERVENTION

The TCC group had practiced TCC regularly for 11.8 +/- 5.6 years, with an exercise frequency of 4.3 +/- 1.3 times per week. Each session included 20 minutes of warm-up, 24 minutes of TCC training, and 10 minutes of cool-down. Exercise intensity was estimated to exceed 70% of maximal heart rate (HRmax).

MAIN OUTCOME MEASURE

Breath-by-breath measurement of cardiorespiratory function was obtained during the incremental exercise of leg cycling. Flexibility of thoracic/lumbar spine was measured by an electronic inclinometer. Percentages of body fat was calculated from biceps and subcapsular skinfolds.

RESULTS

In the peak exercise, men in the TCC group showed 19% higher peak oxygen uptake (VO2peak) in comparison with their sedentary counterparts (26.9 +/- 4.7 mL/kg/min vs 21.8 +/- 3.1 mL/kg/min). Women in the TCC group also showed 18% higher VO2peak than in the sedentary group (20.1 +/- 2.9 mL/kg/ min vs 16.5 +/- 2.0 mL/kg/min). The TCC group also showed higher oxygen uptake at the ventilatory threshold. In addition, the TCC practitioners were characterized by greater flexibility and lower percentage of body fat in comparison with their sedentary counterparts.

CONCLUSION

It is concluded that TCC training has benefits for health-related fitness, and it may be prescribed as a suitable conditioning exercise for the elderly.

[Quadrant pattern visual evoked potential in normal eyes]

OBJECTIVE

The study was designed to approach the difference in pattern visual evoked potential (PVEP) among quadrants of the normal eye.

METHODS

Quadrant transient PVEP method was used to record quadrant PVEP for 70 eyes of 35 normal subjects.

RESULTS

The latency of P100 in lower temporal and lower nasal fields was significantly shorter than that in upper temporal and upper nasal fields; the amplitude of P100 in lower temporal and lower nasal fields was significantly higher than that in upper temporal and upper nasal fields. Generally, in lower field, the P100's latency is shorter and its amplitude higher.

CONCLUSION

The difference in P100 between upper and lower field of normal person is possibly related to the fact that the lower field is used more frequently than the upper in ordinary human or animal life, and to the differences in distribution of retinal ganglion cells and in retina-cortex pathway between the upper and lower retina.

Two-year trends in cardiorespiratory function among older Tai Chi Chuan practitioners and sedentary subjects

OBJECTIVE

To evaluate the training effects of Chinese shadow boxing, Tai Chi Chuan (TCC), on the maintenance of cardiorespiratory function in older individuals.

DESIGN

Prospective study of a cohort of TCC practitioners and a group of sedentary controls examined 2 years after initial examination.

SETTING

Research project at a hospital-based exercise physiology laboratory.

PARTICIPANTS

Eighty-four community-dwelling older adults (mean age: 64 +/- 9 years) with no significant cardiovascular, pulmonary, and musculoskeletal disease completed this study. The TCC group, 23 male and 22 female subjects, had been practicing TCC regularly for 6.7 +/- 3.3 years. The control group included 21 male and 18 female sedentary subjects with age and body size matched to the TCC group.

INTERVENTION

During the period of the study, the TCC practitioners practiced TCC 5.0 +/- 1.1 times per week. Each session included 20 minutes of warm up, 24 minutes of TCC training, and 10 minutes of cool down. The baseline cardiorespiratory function was recorded in the initial exercise test. The same measurements were repeated 2 years later to determine the rate of decline of cardiorespiratory function. Furthermore, heart rates (HR) were monitored in 18 men and 16 women during the performance of TCC to determine the exercise intensity of TCC.

MAIN OUTCOME MEASURE

The study measured 2-year trends of cardiorespiratory function in both groups.

RESULTS

In the TCC group, the males showed a 2.8% decrease in maximal oxygen uptake (VO2max) from 31.6 +/- 7.6 mL x kg-1 x min-1 to 30.7 +/- 7.1 mL x kg-1 x min-1; the females showed a 2.9% decrease in VO2 max from 20.7 +/- 2.3 mL x kg-1 x min-1 to 20.1 +/- 2.5 mL x kg-1 x min-1. In contrast, the male control group showed a 6.6% decrease in VO2max from 24.4 +/- 4.4 mL x kg-1 x min-1 to 22.8 +/- 4.4 mL x kg-1 x min-1; the females showed a 7.4% decrease in VO2max from 16.2 +/- 2.3 mL x kg-1 x min-1 to 15.0 +/- 2.7 mL x kg-1 x min-1. At the ventilatory threshold (VeT), the sedentary group also showed a significant decrease in VO2. During the steady-state performance of TCC, subjects' mean HR was approximately the HR at the VeT (53-57% of HRmax reserve).

CONCLUSION

The data substantiate that practicing Tai Chi Chuan regularly may delay the decline of cardiorespiratory function in older individuals. In addition, TCC may be prescribed as a suitable aerobic exercise for older adults.

Breathing-coordinated exercise improves the quality of life in hemodialysis patients

Breathing-coordinated exercise is a traditional Chinese exercise. These exercise maneuvers consist of slow diaphragmatic breathing, end-inspiratory pause, and Kegel's exercise. A total of 30 patients were enrolled in this study, with 12 patients as controls, to evaluate its effect on hemodialysis patients. Exercise was performed for 25 to 30 min twice a day for at least 3 months. Results from the exercise group showed a subjective improvement in appetite and physical strength, and an increase in the frequency of bowel movements, in addition to enhanced sexual activity and a significant increase in Karnofsky scores. Six patients in the exercise group underwent bicycle ergometry and demonstrated a stable maximal oxygen consumption, whereas the control group revealed a decline in maximal oxygen consumption. Photoelectric plethysmography and laser-Doppler flowmetry demonstrated a pulsatile enhancement of the peripheral microcirculation. Abdominal sonography revealed an oscillatory change in the diameter of the inferior vena cava. It was concluded that these gentle exercise maneuvers may improve the quality of life in hemodialysis patients, especially weak dialysis patients. The mechanism may be partly related to an improvement in microcirculation.

Social aspects of malaria in Heping, Hainan

This paper presents findings from a study conducted in Heping Town, Qiongzhong County, Hainan Province, China. The study, conducted in 1992, used qualitative as well as quantitative methods to gather social, cultural and behavioural data associated with the acquisition, transmission and prevention of malaria, and the diagnosis and treatment of disease. These methods included focus groups, key informant and other in-depth interviews, and observations, a household survey and tests of school children of knowledge of malaria. The study is among the first to our knowledge that has utilized this broad mix of methods for tropical disease research in China.

Cardiorespiratory responses of Tai Chi Chuan practitioners and sedentary subjects during cycle ergometry

Tai Chi Chuan (TCC; shadow boxing) is a traditional Chinese conditioning exercise. To evaluate its beneficial effect on cardiorespiratory function, 21 male and 20 female TCC practitioners, ranging in age from 50 to 64 years, voluntarily participated in this study. The control group comprised 23 male and 26 female sedentary subjects. Breath-by-breath measurement of the cardiorespiratory function was obtained during the incremental exercise of leg cycling. At the maximal exercise level, the oxygen uptake (VO2), O2 pulse and work rate of the TCC group were significantly higher than the respective values of the control group (p < 0.01). At the ventilatory threshold, the TCC group also showed a higher VO2, O2 pulse and work rate (p < 0.05). The results imply that TCC training may be beneficial to the cardiorespiratory function of older individuals. To estimate the exercise intensity of TCC, heart rate (HR) was monitored in 15 men and 15 women while they performed the classical Yang TCC. During the steady-state performance of TCC, the mean HR was 130 +/- 14 bpm for men and 127 +/- 13 bpm for women. The mean HR during TCC exceeded 70% of their HRmax. Our data substantiate that TCC is aerobic exercise of moderate intensity, and it may be prescribed as a suitable conditioning exercise for the elderly.

Traumatic spinal cord injuries in the rural region of Taiwan: an epidemiological study in Hualien county, 1986-1990

In order to survey the epidemiological characteristics of traumatic spinal cord injuries (SCI) in Hualien county, a retrospective study was conducted from January 1986 to December 1990 in four local general hospitals. During this period, 135 traumatic SCI patients were identified and 99 of them were residents of Hualien county. The estimated annual incidence of traumatic SCI in Hualien county was 56.1 per million population. As a result of injury 36 patients were tetraparetic, 33 tetraplegic, 12 paraparetic and 18 paraplegic. The male/female ratio was 4:1. The mean age of onset for male patients was 44 years, and that for female patients was 46 years. The major causes of SCI were traffic accident (61.6%) followed by accidental falls (23.3%). The average duration of hospitalisation ranged from 62 days in paraparetics to 132 days in tetraplegics. Ten patients died of respiratory failure or sepsis, and the mortality rate was 10.1%. Our data revealed that traumatic SCI was prevalent in Hualien county in comparison with epidemiological studies elsewhere. The special population composition of Hualien county and the preponderance of the motorcycle as a transportation vehicle in this area might result in its unique epidemiological characteristics.

[Progressive supranuclear palsy: clinical report on 7 cases and review of literature]

Progressive supranuclear palsy is sufficiently rare and difficult to diagnose that it escaped clinical recognition until 1964, when Steele, Richardson, and Olszewski clarified it as a pathologic entity. From January 1981 to June 1989, 7 patients who fulfilled the Golbe's criteria of progressive supranuclear palsy were admitted to the neurological department of National Taiwan University Hospital. The mean age at onset was 60 years (range: 53-69 years), and the mean age at diagnosis was 63 years), and the mean age at diagnosis was 63 years (range: 55-71 years). The study failed to identify any specific risk factors associated with progressive supranuclear palsy. Unsteady gait, vertical gaze palsy, pseudobulbar palsy, parkinsonian features and dementia were noted in all cases. The brain computed tomography revealed mild cortical atrophy and ventricular dilatation in 5 patients. Additionally, electroencephalography revealed diffuse theta waves in 4 patients and temporal theta waves in 2 patients, but these findings were nonspecific. Nystagmograms were performed in 3 patients, and hypometric saccades were noted in all of these patients, and uninhibited neurogenic bladder was proven by cystometry in 2 of these patients. All patients were treated with levodopa, but none of the patients showed any beneficial effects. Two patients died of aspiration pneumonia; the average duration from onset to death was about 4 years.

A pseudoinverse filter for limited-angle diffraction tomography involving objects with planar structure

A reconstruction technique for limited-angle diffraction tomography is described in which a special pseudoinverse filter is applied to the back-propagation. Using this approach, it is possible to reconstruct a ten-layered object with only 19 projections having angles ranging from -10 degrees to +10 degrees . It is concluded that the algorithm proposed here offers an efficient and computationally easy method for reconstructing an object with planar structure. Even when the number of layers is large and the range of incident angle is limited, the method will give good images.

Involvement of descending inhibition in the effect of acupuncture on the splanchnically evoked potential in the orbital cortex of cat

The possible involvement of descending inhibition in the effect of acupuncture on the transmission of visceral afferent impulses has been investigated. Averaged splanchnically evoked potentials were recorded in the orbital cortex of the unanesthetized immobilized cat. The evoked orbital potentials could be inhibited by electroacupuncture. Section of the descending inhibitory pathway which is known to be located in the dorsolateral funiculi of the spinal cord produced marked diminution of the acupuncture inhibitory effect on the evoked cortical potentials with needles either inserted in the hindlimb or in the forelimb. Since the afferent impulses from the forelimb entered the cord above the level of section (T3-4), the ascending pathway for acupuncture signals to the supraspinal structure was thus left intact. Destruction of the pontobulbar reticular formation including mainly the nucleus raphe magnus produced the same diminution of the acupuncture effect. The results indicate that the ascending visceral afferent impulses are blocked at the level of the spinal cord by the acupuncture-induced descending impulses from the supraspinal center, probably the nucleus raphe magnus.