Biomedical subjects
Publications and source records attributed to Y Xu.
The effect of verapamil (Ver) on CVB3 murine myocarditis was investigated. It was found that Ver could aggravate the myocardial inflammation, increase the viral replication in myocardium, and raise mortality in mice with viral myocarditis when the drug was injected within the first 6 days after the CVB3 inoculation.
In order to investigate the mechanism and treatment of angina decubitus, 20 patients (18 men and 2 women aged 36-70 years) were studied during hospitalization. All patients were found to have an increased heart rate x systolic blood pressure product before the onset of angina decubitus, indicating that this type of angina pectoris belongs to the category of effort angina. Of the 11 patients investigated by continuous hemodynamic monitoring, 3 had significant progressive increases in pulmonary artery systolic pressure (PASP) and pulmonary artery diastolic pressure (PADP) before onset: their episodes of angina could not be completely controlled by digoxin and diuretics, but quickly subsided after beta blockers were added. Among the other 8 patients, PADP increased slightly in 5 and remained unchanged in 3 cases before onset: these patients had no manifestations of LV dysfunction, and beta blockers combined with coronary vasodilators produced satisfactory effects. These results indicate that LV failure is not a major factor in the pathogenesis of angina decubitus. The LV diastolic dysfunction seen in 8/11 cases may have been related to LV hypertrophy caused by long-term hypertension or chronic persistent ischemia.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The purpose of this investigation was to determine the biochemical composition of the normal adult dog's temporomandibular ligament (TML) along its ligament (TML) along its length. Water content and hexosamine concentration as an index of glycosaminoglycan content and collagen concentration were quantified; and the results compared statistically with anatomically identified TML segments. The TML contained lower water content and higher collagen, hexosamine concentration than capsule (P less than 0.05). All the contents of these components in different locations along the ligament were not significantly different, with the exception that on the insertion site of the temporal eminence the concentration of the hexosamine was less than that in other areas (P less than 0.05). This study provided useful data for the analysis of TML functions and its mechanical properties.
Mouse myeloma cells (SP2/0) were incubated with 125I-5s rRNA from rabbit reticulocytes and processed for autoradiography. The results indicated that 5s rRNA could pass into the nuclei of mouse myeloma cells. In a separate experiment, SP2/0 were incubated with cold 5s rRNA, then with 3H-TdR and processed for autoradiography. It was found that in the mouse myeloma cells, DNA synthesis and cell division were obviously suppressed. In another series of experiments, rRNA was extracted from rabbit bone marrow, reticulocytes and erythroid cells and from rat embryonic liver and erythroid cells. The rRNA was analyzed by agarose electrophoresis. It was found that the amount of 5s rRNA in various stages of erythroid development changed along with the denucleating process. Thus it seems likely that 5s rRNA from mammalian erythroid cells could play a role in reversing the malignant phenotype of tumor cells and denucleation of mammalian erythroid cells through inhibiting DNA synthesis.
The stress distribution of the lumbar spine was analyzed with a mechanical model of the lumbar motion segment constructed by a three-dimensional finite element method, and the results were compared with the corresponding bone density represented by the value of CT. The results showed that the stress levels in the various parts of the lumbar spine were closely related to the CT values. The authors conclude that the dynamic balance of bone growth is maintained in large part by mechanical stress.
The severity, extent and localization of regional wall motion abnormalities (RWMA) were quantitatively assessed with apical biplane two-dimensional echocardiography (2DE) using a fixed-axis system, ten-segment division area method in 56 patients with old myocardial infarction (OMI). RWMA were found to be more severe in the anterior wall MI (AWMI) group than in the inferoposterior wall MI (IWMI) group and most severe in the extensive AWMI with ventricular aneurysm (EAWMI with VA) group; the extent of RWMA was smallest in the IWMI group, significantly larger in the AWMI group, and largest in the EAWMI with VA group. The location of the RWMA segments showed group-specific tendencies. For example, both coronal and sagittal apices were much more frequently involved in both the EAWMI with VA and the AWMI groups than in the IWMI group (100%, 87% and 0%, respectively, all P < 0.001). The results demonstrated that quantitative analysis of RWMA using 2DE in cases of MI is accurate and feasible.
The mandibular joints of Chinese Anouroserex squamipes, spuamipes, MILNE-EDWARDS were examined by gross and microscopic studies. We discovered that there were two pairs of joints in these animals. The upper pair of joints, named lateral mandibular joints, were placed on both sides under the parietal bone. The lower pair of joints, named skull-base mandibular joints, were placed on both sides of the skull-base. These two pairs of joints could not be observed simultaneously in the same plane either sagittally or frontally. The lateral fossa and condyle were obliquely from outward, backward and upward to inward, forward and downward on both sides; the fossa looked like a groove concave downward, and the head of the condyles appeared in a cylindrical form. The lower fossae and condyles were transversely forward and inward from the lateral mandibular joints; the fossa looked like a shallow spoon concave upward, and the condyle appeared in a flat surface to fit the upward fossa. The sorex likes to dig holes on the ground to live in and search for insects in the soil to eat. The skull-base mandibular joints will support the jaw to counteract the digging force and protect the lateral mandibular joints from injury. This study has suggested that the morphology of the mandibular joints is adapted to their functional requirements during evolution.
Silent myocardial ischemia was studied in 100 patients with coronary heart disease (CHD), proved by the coronary arteriogram (at least one major coronary artery narrowed by > or = 50%). The study demonstrated that 51 of 100 patients with CHD had episodes of myocardial ischemia by Holter monitoring. In the 51 patients, during daily activities, through 24-hour Holter monitoring, 239 transient episodes of ST depression were detected, 161 of the total were asymptomatic (67.4%). There were no statistically significant differences in the heart rate and the product of heart rate and systolic blood pressure before ST depression between asymptomatic and symptomatic episodes. The heart rate at the time of maximal ST depression during both asymptomatic and symptomatic ischemia increased by 13 and 22 beats/min, respectively, over those before ST depression (P < 0.01); whereas the increase in heart rate during symptomatic ischemia was more significant than during asymptomatic ischemia (P < 0.01). The increase of product of heart rate and systolic blood pressure at the time of maximal ST depression during asymptomatic and symptomatic ischemia were 22.2 and 35.4, respectively, over those before ST depression (P < 0.01). The incidence of silent ischemic episodes in patients with single vessel disease was 81.7% and those with multivessel disease was 61.3% (P < 0.01). The frequency of silent ischemic episodes was maximal (36% of total number of ischemic episodes) between 6 a.m. and 12 a.m. during 24-hour, whereas the incidence of silent ischemic episodes in patients with single vessel disease was similar to that in patients with multivessel disease.(ABSTRACT TRUNCATED AT 250 WORDS)
The components, toxicology, bioactivity and application of fibers of Radix Ophiopogonis (RO) were studied. The components of its fibers and roots are similar. In a clinical study with 100 aged patients, the aging syndromes were markedly improved. No side-effect was found.
Changes of beta-endorphin (beta-EP) and its mRNA in pituitary (P), hypothalamus (HT), lymphocytes (LC) and blood plasma (BP) during cold acclimation of SD male rats were studied by beta-EP mRNA dot blot, RP-HPLC and beta-EP radio-immunoassay (RIA). Experimental results showed: (1) After cold-exposure for 1 week pituitary beta-EP mRNA increased significantly with the appearance of stimulated cellular immune function. (2) beta-EP mRNA in hypothalamic immune center and peripheral LC increased when cold acclimation of animals was established for a cold exposure of 2 weeks (C2W). (3) From C2W onward, plasma beta-EP also continued to increase, indicating an augmented state of cellular immune function. As LC and plasma beta-EP product continued to show increase, pituitary beta-EP mRNA content recovered to control level from C2W onward possibly due to a feedback mechanism through LC-P-HT axis.
The expression of the chimeric gene delta KpF in which the promoter region of delta-crystallin gene was replaced with the long terminal repeats (LTR) of Friend spleen focus forming virus (SFFV) was studied in transgenic mice for approaching the regulatory mechanism of the expression of chicken delta-crystallin gene. The recombinant plasmid (p delta KpF) DNA containing delta KpF gene was microinjected into male pronuclei of fertilized mouse eggs. The injected eggs were implanted into the oviducts of pseudopregnant female mice and allowed to develop to term. Subsequently, 35 mice from those eggs were born. The mice were analyzed at 2 weeks of age with respect to gene integration and expression by the method of DNA blot hybridization and immunoenzymologic assay. DNA-DNA hybridization indicated that the genomic DNA from one of the mice retained the sequences that hybridized strongly with the probe, p delta KpF. Enzyme linked immunosorbent assay (ELISA) showed that delta KpF gene was expressed in the lens, but not in the brain, muscle and liver. These results demonstrate that the essential regulatory elements for tissue-specific expression of chicken delta-crystallin gene reside in the sequences downstream from +677bp.
Thirty-four unique-sequence microclones were isolated from a previously described microdissection library of human chromosome 21 and were regionally mapped using a cell hybrid mapping panel which consists of six cell hybrids and divides chromosome 21 into eight regions. The mapping results showed that the microclones were unevenly distributed along chromosome 21, with the majority of microclones located in the distal half portion of the long arm, between 21q21.3 and 21qter. The number of unique-sequence clones began to decrease significantly from 21q21.2 to centromere and extending to the short arm. This finding is consistent with those reported in other chromosome 21 libraries. Thus, it may be inferred that the proximal portion of the long arm of chromosome 21 contains higher proportions of repetitive sequences, rather than unique sequences or genes. The microclones were also characterized for insert size and were used to identify the corresponding genomic fragments generated by HindIII. In addition, we demonstrated that the microclones with short inserts can be efficiently used to identify YAC (yeast artificial chromosome) clones with large inserts, for increased genomic coverage for high-resolution physical mapping. We also used 200 unique-sequence microclones to screen a human liver cDNA library and identified two cDNA clones which were regionally assigned to the 21q21.3-q22.1 region. Thus, generation of unique-sequence microclones from chromosome 21 appears to be useful to isolate and regionally map many cDNA clones, among which will be candidate genes for important diseases on chromosome 21, including Down syndrome, Alzheimer disease, amyotrophic lateral sclerosis, and one form of epilepsy.
We have used a combination of classical RFLPs and PCR-based polymorphisms including CA repeats and single-strand conformation polymorphisms to generate a fine-structure genetic map of the distal long arm of chromosome 4q. This map is now genetically linked to the pre-existing anchor map of 4pter-4q31 and generates, for the first time, a complete linkage map of this chromosome. The map consists of 32 anchor loci placed with odds of greater than 1,000:1. The high-resolution map in the cytogenetic region surrounding 4q35 provides the order 4cen-D4S171-F11-D4S187-D4S163-D4S139-4q ter. When we used somatic cell hybrids from a t(X;4)(p21;q35) translocation, these five markers fell into three groups consistent with the genetic map-D4S171 and F11 in 4pter-4q35, D4S163 and D4S139 in 4q35-4qter, and D4S187 as a junction fragment between these two regions. These markers are in tight linkage to the gene for facioscapulo-humeral muscular dystrophy (FSHD) mapped to this region by several collaborating investigators and provide a framework for further detailed analysis of this region.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.