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Biomedical subjects

R Ma

Publications and source records attributed to R Ma.

At least 73 records · Page 4Linked to original sources
PubMed1998

Clinical features of the femoral head necrosis caused by gross teres ligament after reduction for the developmental dislocation of the hip.

OBJECTIVE: To observe the clinical features of the femoral head necrosis caused by a gross teres ligament after reduction of developmental dislocation of the hip and study its pathological causes. METHODS: Ten hips with necrosis of the femoral head after reduction of developmental dislocation of the hip were observed. X-ray images of the hip were retrospectively reviewed with regard to the acetabular index, the acetabular-head index, the shapes and the development of the femoral heads. The operative findings were analyzed. RESULTS: No growth or delayed growth of the femoral head and the acetabular index was found after reduction. The recovery of acetabulum was very slow. All of the cases showed the same features: femoral head necrosis, subluxation, and acetabular dysplasia. A gross teres ligament was proved during surgical operation. The femoral head recovered gradually after the operation. CONCLUSIONS: The gross tissue interposed (a gross teres ligament) is another important pathogenesis of femoral head necrosis after the reduction of developmental dislocation of the hip. It is necessary to recognize it before reduction by imaging examinations.

Acetabulum↗
PubMed1998

[Clinical study on effect of Fuzheng Kangbai Granule on long-term survival of patients with acute leukemia].

OBJECTIVE: To observe the effect of Fuzheng Kangbai Granule (FZKBG) on event free interval (EFI) and over survival (OS) of patients with acute leukemia, and to study the mechanism of FZKBG. METHODS: FZKBG was used in 90 cases of completely remitted acute leukemia, immune functions of patients before and after using FZKBG were measured. RESULTS: Five year EFI and OS were 64.2% and 77.2% of 90 cases of completely remitted acute leukemia, and the immune functions after using FZKBG have improved significantly. CONCLUSIONS: FZKBG could increase the EFI and OS of patients with acute leukemia, and the improved immune functions may play a role in increasing 5 year EFI and OS.

Adolescent↗
PubMed1998

[Application of multistage evaluation scale in subjective assessment of mental workload].

The efficiency of multistage evaluation scale (MES) based on the fuzzy set theory as used in subjective assessment of mental workload was studied, and the results were compared with those of tracking performance and category scale (CS). It was found that error (ER) significantly increased when task became more difficult (P < 0.01) and the scalings of MES and CS also increased, but that of MES was significantly different in tasks of all the three difficulties (P<0.01) while those of CS was significant only between tasks 1 and 3 as well as tasks 2 and 3 (P <0.01), but not between tasks 1 and 2. These show that the result of MES is more agreeable with that of ER. So it might be a better subjective assessment measure of mental workload.

Adult↗
PubMed1998

[Effects of task load level and input modality format on P3 wave of event related brain potential].

With different task load levels and input modality formats, P3 wave of event related brain potential (ER-P) were recorded and analyzed in eighteen healthy young man performing six dual tasks. The dual task was made up of visual tracking primary task (T) and Sternberg additional task (S) or Oddball additional task (O) (TS and TO). Its difficulty was controlled by changing the velocity and dimension of movement of target in primary task. The results showed that P3 latency (LAT) prolonged when the primary task was more difficult and its changes of amplitude(AMP) depended on the input modality formats of primary task and additional task. AMP of TO dual task with different formats decreased when the primary task was more difficult and that of TS with same formats increased. It suggests that task load level and input modality format may influent P3 wave of event related brain potential.

Acoustic Stimulation↗
PubMed1998

[Exfoliative cancer cells in the surgical field of breast cancer].

OBJECTIVE: To study the relationship between exfoliative cancer cells in the surgical field and pathological stages of breast cancer and provide a theoretical basis for killing or removing of the exfoliative cancer cells in the surgical field. METHOD: Cytological examination of surgical field washings was performed in 104 patients with breast cancer. The results and pathological stages were compared and analysed. RESULT: Exfoliative cancer cells were found in the surgical field washings in 36 of 104 (34.6%). Stage I, II and III showed a positive rate of 3.8%, 29.8% and 85.7%. The positive rate of T(1), T(2) and beyond T(3) were 10.8%, 33.3% and 77.3%, respectively. When the number of axillary metastatic lymph nodes was over four, the positive rate of exfoliative cancer cell was 76.0% and only 13.5% if no axillary lymph node metastasis. CONCLUSION: Killing or removing of the exfoliative cancer cells in the surgical field of breast cancer is necessary.

Biopsy↗
PubMed1998

[Application of time-frequency filter of wavelet to single-trail ERP extracting].

A new approach to extracting single-trail event-related potential(ERP) in combination with the correlation analysis has been proposed. This approach, called time-frequency filter, is based on the concept that multiresolution wavelet transforms. At first, an investigation of the properties in time and frequency domain was carried out on the ERP. On the basis of the findings, the time-frequency filter of wavelet was designed and used for single-trail ERP extracting. The results and related discussion are presented in this paper.

Adult↗
PubMed1997

Effects of maternal oral administration of monosodium glutamate at a late stage of pregnancy on developing mouse fetal brain.

Monosodium glutamate (MSG) was shown to penetrate placental barrier and to distribute to embryonic tissues using [3H]glutamic acid ([3H]Glu) as a tracer. However, the distribution is not even; the uptake of MSG in the fetal brain was twice as great as that in the maternal brain in Kunming mice. Other maternal mice were given per os MSG (2.5 mg/g or 4.0 mg/g body weight) at 17-21 days of pregnancy, and their offspring behaviors studied. The results showed that maternal oral administration of MSG at a late stage of pregnancy decreased the threshold of convulsion in the litters at 10 days of age. Y-maze discrimination learning was significantly impaired in the 60-day-old filial mice. On the other hand, no significant difference in spatial learning or tail flick latency was measured between the experimental animals and the controls. The filial mice of MSG-treated mothers could either not grasp a rope tightly, or grasped the rope tightly but could not crawl along the rope at the beginning of the training. However, such mice, after training, could grasp and crawl along the rope as well as controls. Obvious neuronal damage was not detected in the periventricular organs or the hypothalamus under a light microscope. The rate of weight gain for experimental animals was greater than for controls throughout the period from 20 to 90 days. Mating of treated males with treated females resulted in pregnancies and normal offspring, indicating that oral administration of MSG at a late stage of pregnancy did not affected the reproductive capacity of the offspring. The possible differences and relationship between MSG-induced damage to developing human and rodent brain are discussed.

Administration, Oral↗
PubMed1997

Anthropometrics do not influence dual X-ray absorptiometry (DXA) measurement of fat in normal to obese adults: a comparison with in vivo neutron activation analysis (IVNA).

Dual-energy X-ray absorptiometry (DXA) is now a commonly used method for the determination of bone mineral status and body composition in humans. The purposes of this study were to compare fat mass by in vitro neutron activation analysis (FMIVNA) with that by DXA (FMDXA) in an anthropometrically heterogeneous sample of healthy adult men (n = 33) and women (n = 36) (19 < or = BMI < or = 39), and to determine whether differences in fat mass estimates between the two methods (delta FM) were attributable to subject anthropometry as defined by several circumference (waist, iliac crest, thigh) and skinfold thickness (umbilical, suprailiac, abdominal) measurements. No significant differences between FMDXA and FMIVNA were observed in men (p = 0.46) or women (p = 0.09). The two methods were very highly correlated in both sexes (women r2 = 0.97, p < 0.001, men r2 = 0.91, p < 0.001), although the regression line for men was significantly different from the line of identity (p = 0.043). These results suggest modest trends toward underestimation of FMDXA in men when FMIVNA < 18 kg, and overestimation in men when FMIVNA > 18 kg. delta FM (IVNA-DXA) was not significantly related to any combination of skinfold thickness and circumferences in either gender. Age explained 27% of the variance in delta FM for the men (p = 0.008). Furthermore, delta FM was not significantly related to inter-method disparity in total-body bone mineral measurements in men or women (p < 0.05). The present study demonstrates strong correlation in fat measurements between IVNA and DXA in men and women ranging from normal to markedly obese. Correction for subject anthropometry does not significantly improve this relationship.

Absorptiometry, Photon↗
PubMed1997

Comparison of body composition in black and white premenopausal women.

We examined 23 pairs of black and white premenopausal women to determine whether there were ethnic differences in body composition. The pairs were matched on weight and height. Each woman had measurements of total body water taken by a tritiated water dilution technique, total body nitrogen, and total body carbon by neutron-activation, mineral ash by dual x-ray absorptiometry, and body potassium by whole body counting. Differences between blacks and whites were compared with the use of both the two-compartment and four-compartment models. The two-compartment model showed that in premenopausal black and white women of similar age, heights, and weights, blacks had significantly more lean mass. The four-compartment model resulted in similar conclusions. The black women had larger protein, mineral, and water compartments and less fat than whites. It may be that body weight measurements as an indicator of obesity should be adjusted for black versus white women.

Absorptiometry, Photon↗
PubMed1997

A multi-center comparison of dual energy X-ray absorptiometers: in vivo and in vitro soft tissue measurement.

OBJECTIVE: To assess intra- and inter-site soft tissue variability by dual energy X-ray absorptiometry (DXA). DESIGN: Cross-sectional trial. SETTING: Three medical research institutions. SUBJECTS: Five humans (in vivo) and four phantoms (in vitro), configured from two whole body phantoms with artificial skeletons and thickness overlays. INTERVENTIONS: Duplicate total-body DXA scans were performed on all subjects at each institution within a 15 d period. RESULTS: All intra-site coefficients of variation (CV) were < 0.5% for total tissue mass, but in vitro and in vivo Cvs were 7.2% and 2.3% for fat mass (FM) and 2.5% and 0.9% for lean mass (LM), respectively. Several total-body and regional FM and LM measurements were significantly different between sites (P < 0.05), with percent differences between sites ranging from 2.6-13.3% for FM and from 1.6-13.6% for LM. Site 2 was consistently lower for FM and Site 3 was consistently lower for LM. CONCLUSIONS: These results stress the need for both rigorous and standardized cross-calibration procedures for soft tissue measurement by DXA.

Absorptiometry, Photon↗
PubMed1997

A modified bottle manikin phantom for in vivo neutron activation analysis.

An artificial skeleton was designed and placed inside a bottle manikin absorber phantom to provide a new reference standard for measurements of total body calcium by in vivo neutron activation analysis at Brookhaven National Laboratory. The composition of the epoxy-based calcium and phosphorus mixture used to construct the skeleton, the dimensions and weight of each bone are given for two phantoms representing an adult male and female. Also, the dimensions, composition, and weights of overlays designed to simulate the influence of obesity on in vivo neutron activation analysis are given for each.

Adult↗
PubMed1997

Central gain of the cardiac sympathetic afferent reflex in dogs with heart failure.

Previous studies from our laboratory have shown that the cardiac sympathetic afferent reflex is enhanced in dogs with experimental heart failure. The aim of the present study was to determine if the central gain of the cardiac sympathetic afferent reflex was also enhanced in dogs with heart failure. Fifteen dogs with pacing-induced heart failure were used in this study. Seventeen sham-operated dogs served as control. At the time of the acute experiment the dogs were anesthetized with alpha-chloralose. Arterial blood pressure, heart rate, and renal sympathetic nerve activity were recorded. After sinoaortic denervation and cervical vagotomy, a thoracotomy was performed in the second intercostal space. The left stellate ganglion was identified, and the left cardiac sympathetic nerves were cut. The central end of the left cardiac sympathetic nerves was placed on bipolar stimulating electrodes. The renal sympathetic nerve activity responses to electrical stimulation (30 Hz, 1 ms with varying voltages from 1 to 10 V; or 10 V, 1 ms with varying frequencies from 1 to 30 Hz) of the afferent cardiac sympathetic nerves were compared between sham and heart failure groups. Reflex renal sympathetic nerve activity responses to stimulation of the cardiac sympathetic nerves were significantly greater in the heart failure group compared with that in the sham group (21.4 +/- 3.2 vs. 9.8 +/- 2.9% at 10 V, 30 Hz and 27.7 +/- 4.5 vs. 9.9 +/- 3.4% at 30 Hz, 10 V, heart failure vs. sham group, respectively; for both relationships, P < 0.05). This enhanced central gain of the cardiac sympathetic afferent reflex in the heart failure group was significantly attenuated after intravenous and cerebroventricular injection of the angiotensin II receptor antagonist losartan (5 mg/kg i.v. and 0.125 mg/kg in 0.1 ml i.c.v.). These data suggest that the central gain of the cardiac sympathetic afferent reflex is enhanced in dogs with heart failure and central angiotensin II plays an important role in this enhanced response.

Afferent Pathways↗
PubMed1997

[Multivariate discriminant analysis for assessing mental workload during duel task operation].

In order to investigate the efficiency of multivariate discriminant analysis in the assessment of mental workload during dual task operations, various psychophysiological indices and performance were recorded. The dual task consisted of the primary visual tracking task and the secondary Oddball task. The results indicated that tracking error, latency of P3 and IBI of HR correlated well with the mental workload and the multivariate discriminant analysis succeeded in classifying the levels of mental workload with higher conformation rate than those using the single index. It suggests that multivariate discriminant analysis is meaningful in the assessment of mental workload under dual task situations.

Aerospace Medicine↗
PubMed1997

[Comparative study on the lysis of leukemia cells by IL-2 activated bone marrow and cord blood].

OBJECTIVE: To explore the antitumor activity of IL-2 activated bone marrow (ABM) and cord blood (ACB) mononuclear cells. METHODS: The antitumor activity of ABM and ACB mononuclear cells to the K562 (NK sensitive) and HL-60 (NK resistant) cells was studied by 3H-TdR release assay and semisolid culture method. The progenitor cell activity (PCA) of ABM and ACB was also assayed. RESULTS: After coculturing for 24 hrs with IL-2, the tumor-killing activities of ABM to K562 cells and to HL-60 cells were identical, while the activity of ACB to K562 cells was higher than that to HL-60 cells. After 72 hr coculturing, the activities of ABM to K562 and HL-60 cells were still higher than that of ACB. The optimum conditions for the activation of ABM and ACB were 1000U/ml IL-2, 1 x 10(6)/ml cells, 100 : 1 effector to target ratio and 72 hr culturing. PCA was not affected after IL-2 activation, while the immunophenotypic markers changed greatly. TNFalpha and IL-6 were detectable after culturing for 24 hrs, and went higher at 72 hrs. Large granular lymphocytes were generated both in cord blood and bone marrow after 24 hr culturing with IL-2. CONCLUSION: Both bone marrow and cord blood could be activated by IL-2 and gained cytotoxic effects, but the cytotoxicity of ACB was slightly lower than that of ABM under the same culturing condition. The mechanism of cytotoxicity might be cell mediated cytotoxicity and releasing of cytokines such as TNFalpha and IL-6.

Biomarkers↗
PubMed1997

Sodium distribution in black and white women.

Delayed gamma neutron activation analysis (DGNA) was performed on 99 black and 168 healthy white women, aged 20-80 years, to examine sodium distribution in the two ethnic groups. Elements measured included total body levels of sodium (TBNa) and chlorine (TBCl). The black women were heavier, and consequently had a higher body surface area. Sodium excess (Naes) was calculated from TBNa and TBCl. Total body water was measured by tritiated water dilution. TBNa was higher in black than white women, and this difference persisted when the values were corrected for body surface area. TBNa and Naes declined significantly with age in white women, whereas extracellular fluid sodium (ECFNa) remained constant. The change with age was not statistically significant in black women for TBNa, Naes or ECFNa. Our sample of healthy black women had a higher TBNa and Naes than healthy white women. This difference persisted after adjustment for body surface area, so that values for sodium distribution need to be adjusted for race. The change in TBNa with age in white women appears to be due to their decline of skeletal tissue mass with a consequent decline in nonexchangeable sodium.

Adult↗
PubMed1997

Evolutionary regularity of acetabular dysplasia after reduction of developmental dislocation of the hip.

OBJECTIVE: To observe the developmental changes of the acetabulum after reduction of developmental dislocation of the hip and require evolutionary regularity of acetabular dysplasia. METHODS: A follow-up in an average of 7.4 years was carried out in 117 patients (161 hips) with developmental dislocation of the hip after reduction. By the series of X-ray films, acetabular index, acetabular-head index, Sharp's angle, ACM angle (Idelberger's angle) and anteversion were observed. At the same time, centre-head distance discrepancy was measured. RESULTS: Acetabular index returned to normal gradually as the time went by and significantly within one year after the reduction of developmental dislocation of the hip. The process of recovery was nearly stable three years later. Acetabular index in the dysplasia group was above 39 degrees before reduction and decreased slowly after the reduction. However, it was still up to 30 degrees after 3 years observation. The value of centre-head distance discrepancy decreased gradually as the years went by after reduction. CONCLUSIONS: If acetabular index before reduction is above 39 degrees and is still up to 30 degrees three years after reduction, acetabular dysplasia can be diagnosed.

Acetabulum↗