Biomedical subjects
Publications and source records attributed to S Zhao.
RhsF has been identified as the fourth member of the RhsABCF subfamily of genetic elements. This new element is found in Escherichia coli ECOR-50 and several other strains but not in strain K-12. A novel feature of RhsF is that it represents a new arrangement of components previously uniquely associated with RhsA and RhsC of strain K-12.
The development of atherosclerosis is thought to be initiated by a dysfunctional state of the vascular endothelium. The proposal that mechanical forces play a role in the localization of this disease has led researchers to develop in vitro models to assess their effects on cultured endothelial cells. The arterial endothelium is exposed simultaneously to circumferential hoop stretch and wall shear stress, yet previous investigations have focused on the isolated effects of either cyclic stretch or shear stress. The influence of physiological levels of combined shear stress and hoop stretch on the morphology and F-actin organization of bovine aortic endothelial cells was investigated. Cells subjected for 24 hours to shear stresses higher than 2 dyne/cm2 or to hoop stretch greater than 2% elongated significantly compared with unstressed controls and oriented along the direction of flow and perpendicular to the direction of stretch. Exposure to more than 4% stretch significantly enhanced the responses to shear stress. Both shear stress and hoop stretch induced formation of stress fibers that were aligned with the cells' long axes. Simultaneous exposure to both stimuli appeared to enhance stress fiber size and alignment. These results indicate that shear stress and hoop stretch synergistically induce morphological changes in endothelial cells, which suggests that circumferential strain might modulate sensitivity of endothelial cells towards shear stress.
Recent studies demonstrated that exogenous relaxin promoted drinking in nonpregnant rats. The purpose of this investigation was to determine the influence of endogenous relaxin on water consumption in pregnant rats. To that end, a monoclonal antibody specific for rat relaxin, designated MCA1, was used to passively neutralize endogenous relaxin throughout the second half of pregnancy in intact rats. Five milligrams of highly purified MCA1 were administrated iv to rats daily from days 12-22 of pregnancy. Controls received either a monoclonal antibody for fluorescein (monoclonal antibody control) or PBS (vehicle control). The amount of water consumed and both the total duration of water consumption and the total number of episodes when water was consumed were determined daily during both dark and light periods for all treatment groups. From days 13-22 of pregnancy, all three of these parameters of water consumption increased during the 10-h dark period (P < 0.01), but not during the 14-h light period. The mean daily water consumption in MCA1-treated rats was significantly less than that in controls (P < 0.05). Relaxin's effects on water consumption were limited to the 14-h light period (P < 0.01). No difference was found in daily water consumption between the MCA1-treated and control groups during the 10-h dark period. There was a tendency during the light period for both the total duration of water consumption (P = 0.06) and the total number of episodes when water was consumed (P = 0.13) to be less in MCA1-treated rats than in controls. Food consumption and body weight increased as pregnancy progressed, but no differences were found among the three treatment groups. We conclude that endogenous relaxin has effects on water consumption. It promotes water consumption during the daily light period in the second half of pregnancy in rats. Thus, relaxin may be a dipsogenic agent.
Expression of MDR1 is a well-characterized mechanism leading to resistance of tumor cells to drugs like vinca-alkaloids, anthracyclines, and epipodophyllotoxins. In hematopoiesis, recent data indicate that not only leukemic cells, but also some populations of normal hematopoietic cells, particularly CD34+ progenitor cells as well as peripheral blood lymphocytes, express a functional multidrug-resistant phenotype. Among CD34+ cells, we found evidence that myeloid committed precursor cells (CD34+/CD33+) have lower levels of MDR1 expression than earlier CD34+ cell populations, but there was no difference in MDR1 expression between CD34+/HLA-DR- and CD34+/HLA-DR+ subpopulations. During normal myeloid differentiation, MDR1 expression is down-regulated, which is similar to our observations in acute myelogenous leukemia (AML): MDR1 expression was only rarely detected in acute promyelocytic leukemia, which was in contrast to other subtypes of AML; also, within leukemic subpopulations of the same patient, higher MDR1 levels were correlated with a more immature immunophenotype. Regarding regulation of MDR1 expression, we did not observe changes of MDR1 expression in normal CD34+ cells in response to various cytokines. However, in 2 patients with AML treated with interleukin-3 and granulocyte-colony stimulating factor, respectively, a significant down-regulation of MDR1 expression was found after 24 hours. In conclusion, there is evidence that the pattern of MDR1 expression observed in leukemias reflects the distribution of MDR1 in normal hematopoiesis. In contrast to normal CD34+ cells, leukemic cells from some AML patients can respond to cytokines with a down-regulation of MDR1, which may contribute to response to cytokine/chemotherapy combinations.
The Oral Antiasthmatic Liquid, when given into the mice stomach, can obviously reduce the times of cough induced by sulfur dioxide aerosol, and increase the amount of phenolsulfonphthalein excretion of tracheas. It also shows antagonistic action to bistamin phosphate and acetylcholine that can contract the isolated tracheas of guinea-pigs, and reduce the amounts of isolated lung and bronchial perfusion of guinea-pigs.
The level of ADA, LZM, leukocyte count, lymphocyte in tuberculous effusion is higher than that of carcinomatous effusion (P < 0.05). All results showed that the change of multiple parameters is related to the pathological manifestation of pleurae. The false positive or negative result was influenced by pathological appearance and bloody character of pleural effusion. Using the ADA, LZM cut off value at 35U and 30mg, respectively, and pleural/serum ADA ratio > 1.4, LZM > 1.1, a sensitivity and specificity of 100 percent were achieved.
Cellular morphology and nuclear DNA content were measured with point-counting technique and flow cytometry (FCM) respectively in normal nasopharyngeal epithelium (NE), tissue adjacent to carcinoma (ATC) and nasopharyngeal carcinoma (NPC). The results showed that all 20 patients with NE showed diploid, whereas 38 (38%) of 101 patients with NPC, 7 (58%) of 12 patients with recurrent NPC, 6 (30%) of 20 patients with ATC and 2 (33%) of 6 patients with NE positive to EBVCA-IgA test showed nondiploid. A total of 19 morphometric parameters of the cell were measured and calculated. The results showed that with malignant transformation of NE, most of the cellular morphometric parameters gradually increased in numerical values while no marked difference was shown between normal NE and simple hyperplasia or metaplasia in terms of cytomorphometric characteristics. Most of the parameters in dysplasia changed significantly as compared with those normal NE, simple hyperplasia or metaplasia and NPC groups. Cytomorphometric analysis seems to give strong support to the concept that dysplasia is among the transitional stages of disease process between normal NE and NPC. Our results show that morphometric analysis and FCM may offer valuable and objective criteria in the early diagnosis of NPC and premalignant disease.
We modified the examination and evaluation standard of impairment of hand function proposed by the International Federation of Societies for Surgery of the Hand (IFSSH). 1) The thumb adduction and opposition examination is changed from measuring distance alone to calculation of the ratio of thumb length to the distance of movement. 2) Sensation grading and two-point discrimination test are included in the sensory function evaluation. 3) In the estimation of anatomic loss of the hand, instead of measuring the length of the loss, calculation of the area of loss is proposed. 4) In the evaluation of joint movement, besides the angle of movement and position of the joint itself, influence of the defect distal to the joint thereon is also considered. 5) In the original evaluation standard, sensory disturb ances of the palmar and dorsal aspects of the hand as well as the anatomic loss of tissues through the palm are not taken into account. The present work pays special attention to this point. The software of the above mentioned work has been developed, approved by experts and adopted nation wide in China. The data of hand function examinations can be fed into the computer and the function loss in percentage can be displayed, or printed out. This software, using a graphic display, can also take care of the filling and retrieving of case history. At present the menu and instructions are in Chinese, which can be changed to suit other language.(ABSTRACT TRUNCATED AT 250 WORDS)
The inclusion compounds of Jiuxin Oil with beta-cyclodextrin were prepared. The influence of temperature, ratio of host and guest molecules, stirring time on inclusion were observed. The quantitative determination was performed by gas chromatography. Inclusion compounds of Jiuxin Oil were confirmed by differential scanning calorimetry and powder X-ray diffractometry.
Mast cell-nerve relation is a new topic explored deeply in different organs, but little documentation could be found in the literature on the relation in human nasal mucosa. We carried out this study using immunocytochemistry and found that substance P (SP) terminals were present in human nasal mucosa from six cases of chronic rhinitis. SP terminals were often found to be adjacent to or have a direct contact with mast cells (MCs). Electron-microscopic studies revealed that MCs could contact nonmyelinated nerve terminals. These results have important implications in the understanding of the pathogenesis of neurogenic inflammation seen in nasal mucosa and will probably cast new insight into the future treatment of such disease.
To increase the reproducibility and to reduce the false positives in the initial mRNA differential display, modified long composite primers were developed based on both mRNA differential display and RNA arbitrarily primed PCR fingerprinting methods. Ten-base nucleotides were added at the 5' ends of the primers used in the initial mRNA differential display. These included a restriction site to aid cloning. PCR began with one low-stringency cycle (40 degrees C for annealing) followed by 35 high-stringency cycles (60 degrees C for annealing). The modified method significantly improved the reproducibility and sensitivity of the mRNA differential display while still keeping the characteristics of the original method.
Fluorescence assay was applied to the determination of magnolol in rabbit blood, and the best way to administer the bark of official magnolia per rectal was established by orthogonal test. Then the two routes of administration were compared by AUC of magnolol and per rectal was found better than P.O. In addition, the modified isolated rectum-bag method was applied successfully to the research on rectal administration of bark of official magnolia.
100 anterior branches of the lateral cutaneous nerve of the thigh were dissected and measured in 50 adult cadavers. The results show that this nerve is present in all sides. The average length from the point of the nerve piercing fascia lata to the point of its first branch is about 79mm, the average width is 2.25 mm, and the average thickness is 0.79 mm respectively. It is found that the course of the nerve is approximately along the line between the anterior superior iliac spine and the midpoint of the patella. This study is benifit to the facial nerve grafting in clinic by providing data of the nerve.
We have developed a method to estimate primaquine (PQ) and hepatic targeting antimalarial agent neoglycoalbumin-primaquine (NGA PQ) in whole blood and liver of mice by sensitive and selective high-performance liquid chromatography. The primaquine was extracted out with ether from the basified biological samples in the PQ diphosphate group or from the samples which were acidic hydrolyzed then basified in NGA-PQ group. The extracts were evaporated under N2 then dissolved in the mobile phase. A linear chain analogue of primaquine was used as the internal standard. The samples were injected into the normal phase silica column with chloroform: methanol:ammonia solution (86.8:12.5:0.7,V/V/V) as mobile phase and detected at 254 nm. The average recovery of the method was 100.09 +/- 3.46 (mean +/- s)%; the CV of within-day and between-day were 2.7%-6.13% (n = 5) and 8.32%-13.56% (n = 9) respectively; in PQ group and NGA-PQ group, the PQ concentrations ranged from 10-20,000 ng/ml blood or 1g. liver respectively, and they all yielded a good linear relationship with the peak height ratios. No endogeneous interference was found in chromatograms of biological samples.
A TLC-densitometric method was applied to determine aesculin in rabbit blood. The best way for ash bark rectal administration was found by orthogonal design [L4(2(3))]. The two routes of administration (per rectal, P.O.) were compared by bioavailabilities and the result indicated that per rectal was better than P.O. Modified isolated rectum-bag method was applied successfully to finding the best way for rectal administration of ash bark.
PCR technique was applied to detect hypermethylation at BssH II recognition sites within CpG island of FMR-1 gene in normal, affected, and clinically suspected males with fragile X syndrome. Hypermethylation was found to occur in all 7 affected and 5 of 26 suspected, but none of 15 normal males. The results of PCR assay are in good coincidence with those of Southern blot and cytogenetic assays. This PCR assay will be a promising method in the diagnosis of fragile X syndrome in males with mental retardation.
The Yishoujiangzhi (de-blood-lipid) tablets (composed of Radix Polygori Multiflori, Rhizoma Polygonati, Fructus Lycii, Crataegus Pinnatifida and Cassia Tora) were used in the treatment of 130 cases of hyperlipemia, achieving an effective rate of 87.0% in lowering serum cholesterol and 80.8% in lowering triglyceride.
In order to elucidate the relationship between N-, C-termini of TNF alpha and it's biological activity, a TNF alpha derivative 10 (TNF alpha D10) was prepared by changing amino acid at the N-terminus positions Ser(4), Ser(5), Asp(10) and C-terminus position Leu(157) to N-terminus Cys(4), Thr(5), Arg(10) and C-terminus Phe(157) with PCR site-directed mutagenesis. The results showed that the expression level of this mutein has not altered but its cytotoxic activity increased. This might result from trimer formation of TNF alpha D10 by changing N-terminal Ser(4) residue to Cys. HPLC showed that the molecular weight of TNF alpha D10 was 17kD, 35kD, 55kD respectively. In addition, we also found that the stability of TNF alpha D10 was less than that of TNF alpha when to be stored at -20 degrees C for two months. It might be caused by changing Leu(157) to Phe(157).