Biomedical subjects

Z Fu

Publications and source records attributed to Z Fu.

At least 91 records · Page 5Linked to original sources

PubMed1996

Age-of-onset related HLA-DQA1 genetic heterogeneity of insulin-dependent diabetes mellitus.

OBJECTIVE: To clarify whether there is an association of insulin-dependent diabetes mellitus (IDDM) susceptibility with HLA-DQA1 locus in adult-onset IDDM. PATIENTS AND METHODS: Possible heterogeneity in immunogenetic aspects was investigated by comparing the findings on relationship between HLA-DQA1 52 Arg(+) and IDDM predisposition in three groups with different ages of IDDM onset (group A 14 years, group B 15-30 years, group C > 31 years). RESULTS: The frequency of HLA-DQA1 52 Arg(+) in group A (87.5%) was higher than that in control (53.9%, P < 0.05) and in group B and C (P < 0.05). The frequency of HLA-DQA1 52 Arg(+)/Arg(+) phenotype in group A (75%) was higher than that in group C (23.1%, P < 0.05). CONCLUSION: The contribution of HLA-DQA1 52 arginine to IDDM susceptibility is heterogeneous. Further study is necessary to clarify the immunogenetic entity of IDDM.

Adult↗

PubMed1996

[Effects of curcumin derivatives on the GJIC of normal and tumor cells].

Experiments were conducted by using scrape-loading and dye transfer (SLDT) method to study the gap junction intercellular communication (GJIC) of Chinese hamster lung cells (V79), mouse fibrous cells (Balb/c-3T3), rat liver cells (WB) and human embryonal lung cells (2BS). We also observed the inhibition of the GJIC by TPA and the antagonistic effect of Curcumin derivatives on TPA. The results indicated that V79, WB, 3T3 and 2BS normal cells showed medium level of GJIC, and TPA could inhibit the GJIC to some extents. Curcumin derivatives (91022, 91022-S) could counteract the inhibition of TPA-induced GJIC. It was also found that human lung adenocarcinoma cell (A549) and GLC lacked GJIC, and 91022 could improve the GJIC of A549 cell. It may be related to its anticancer activity.

3T3 Cells↗

PubMed1996

[Effects of electroacupuncture on the subcutaneous mast cells of zusanli acupoint in rat with unilateral sciatic nerve transection].

Electroacupuncture could induce the convergence and degranulation of subcutaneous mast cells in acupoints. After unilateral transection of sciatic nerve, we studied the numbers of subcutaneous mast cells and its degranulation in bilateral Zusanli and Xiajuxu acupoints with electroacupuncture in Zusanli. We found that sciatic nerve transection could reduce the total numbers of mast cells and the degranulation numbers of mast cells in Zusanli. The results suggested peripheral nerves play an important role in the convergence and degranulation of mast cells in acupoints by electroacupuncture induction.

Acupuncture Points↗

PubMed1996

[A study of CD23 expression and regulation in the patients with asthma].

To study the pathogenesis of asthma, we examined the CD23 expression on peripheral blood mononuclear cells (PBMC) from 25 healthy donors and 28 asthmatic patients with APAAP test. The results demonstrated that CD23 antigen expressed strongly on PBMC from patients and their PBMC correlated positively with their IgE level (r = 0.78 P < 0.01). We investigated the regulation of CD23 expression by IL-4 and IFN-gamma in vitro, the results demonstrated that IFN-gamma could inhibit spontaneous and IL-4 induced expression of CD23. It was suggested that the analysis of the percentage of positive CD23 expression is useful for making diagnosis and assessing severity of asthma and is of significance in elucidating the pathogenesis of the asthma.

Adult↗

PubMed1996

[Effect of HE-NE laser acupuncture on the spleen in rats].

The splenic sinuses, lymphocytes and antigen presenting cells in the spleen of rat stimulated by He-Ne laser acupuncture were observed by using TEM to investigate the ultrastructural changes of them. The width of endothelial interstice was increased, hence a lot of blood cells oozed out of the splenic sinuses. There were numerous activated T cells which contained abundant mitochondria and ribosome in the periarterial lymphatic sheaths. The B cells were gradually differentiated into large lymphocytes, immature and mature plasmatic cells with a lot of endoplasmic reticula. They were prominently increased in the splenic nodules. The macrophages had short processes with numerous folds and microvilli and tended to neighboring lymphocytes. The nucleus pores were increased. There were a lot of vacuoles, phagosome and mitochondria were closed to macrophages and lymphocytes. In conclusion the activities of the cellular immunity and humoral immunity were enhanced by laser.

Acupuncture Points↗

PubMed1996

[A retrotransposon-like element Tca1 was used for taxonomic determination of Candida albicans].

We had isolated from Candida albicans a moderately repetitive sequence designated alpha and a retrovirus-like transposable element Tcal (Transposon Candida albicans). The Tcal consisted of two 388bp direct repeats of the alpha element, called LTR (Long Termination Repeat), which was separated by approximately 5.5kb of DNA. A large number of strains from America and China have been grouped based on patterns of hybridization bands visualized on Southern blots of EcoRI digested genomic DNA probed with alpha and Tcal element internal sequence. Strains from same area have higher relatedness than those from different area. The hybridization patterns with URA3 and other DNA probes were also conserved within the groups. alpha element are species specific, no hybridization was observed with genomic DNA of other yeast species. The data presented here indicate that the alpha element can be employed to distinguish between species and to assess strain relatedness within C. albicans, we suggest that Tcal may be relevant to the genomic evolutions of C. albicans and the pathogenic potential of the organism.

Candida albicans↗

PubMed1995

Effect of increased duration of high perfusion pressure on stress failure of pulmonary capillaries.

We have previously shown that raising the capillary transmural pressure (Ptm) in rabbit lung causes disruption of the capillary endothelium, alveolar epithelium, or sometimes all layers of the wall. In those studies the lungs were perfused with autologous blood (1 min), then saline/dextran (3 min), followed by glutaraldehyde fixative (10 min), all at the same pressure. The present study was designed to determine whether increasing the time of exposure of the capillaries to the increased pressure altered the frequency of stress failure. The procedure was identical to that of the previous study except that the duration of the blood perfusion was extended from 1 to 10 and 100 min. We chose a Ptm of 32.5 cm H2O because our previous studies showed that this caused only a few disruptions per millimeter endothelial and epithelial boundary length (0.7 +/- 0.4 and 0.9 +/- 0.6 (SE), respectively). Ten New Zealand white rabbit lungs were perfused with autologous blood plus homologous blood from additional rabbits for 10 and 100 min. After 100 min of blood perfusion the number of disruptions per millimeter endothelial and epithelial boundary length (0.66 +/- 0.4 and 0.52 +/- 0.33 (SE), respectively) was not significantly different from the earlier study. Thus, increasing the duration of the increased Ptm during blood perfusion by 100-fold did not alter the incidence of stress failure. These results indicated that any viscoelastic behavior resulting in further strain and ultimately failure of the capillary walls is insignificant over a wide range of exposure times to increased pressure under the conditions of this study.

Animals↗

PubMed1995

Pulmonary capillaries are more resistant to stress failure in dogs than in rabbits.

We previously showed that stress failure of pulmonary capillaries occurs at transmural pressures of approximately 50 cmH2O (40 mmHg) and above in rabbit lung. In this study, we examined whether pulmonary capillaries are more resistant to failure in dogs than in rabbits. This might be expected because of the greater athletic ability of dogs and therefore their presumably greater tolerance to large cardiac outputs and higher pulmonary vascular pressures. The lungs of 12 anesthetized mongrel dogs [22.1 +/- 5.2 (SD) kg] were perfused in situ with autologous blood and then with saline-dextran (5 min) and glutaraldehyde solution (10 min), all three perfusions at the same preset transmural pressure of 32.5, 72.5, 92.5, or 112.5 cmH2O. In dogs, the stress failure curves relating break number per millimeter of epithelium and endothelium were right shifted by approximately 40 cmH2O compared with rabbits. Blood-gas barrier thickness was significantly greater than in rabbits at 32.5 cmH2O, and unlike in rabbits, neither total nor interstitial thickness increased significantly with increasing pressure. These results indicate that pulmonary capillaries are more resistant to stress failure in dogs than rabbits.

Animals↗

PubMed1995

Effect of reducing alveolar surface tension on stress failure in pulmonary capillaries.

We previously showed that when pulmonary capillaries are exposed to high transmural pressures, stress failure of the blood-gas barrier occurs. It has been suggested that the surface tension of the alveolar lining layer may protect against stress failure because at high transmural pressures the capillaries bulge into the alveolar spaces. To test this hypothesis, we abolished the gas-liquid surface tension of the alveoli by filling rabbit lungs with normal saline. The lungs were then perfused at capillary transmural pressures of 32.5 or 52.5 cmH2O for 1 min with autologous blood, the blood was washed out with a saline-dextran mixture (3 min), and the lungs were fixed for electron microscopy with buffered glutaraldehyde; all perfusions were done at the same pressure. The frequency of breaks was measured in the capillary endothelial layer, alveolar epithelial layer, and basement membranes, and the data were compared with those in air-filled lungs at the same capillary transmural pressure and lung volume. We found that the frequency of breaks in the endothelium was not significantly different between air and saline filling and that there were fewer breaks in the outer boundary of the epithelial cells. By contrast, after saline filling, a larger number of breaks were seen in the inner boundary of the epithelium. The frequency of disruptions of the inner boundary of the epithelium was closely correlated with the volume of edema fluid collected at the trachea during the perfusion. These breaks in the inner boundary of the epithelium had not previously been seen in air-filled lungs exposed to the same pressures. The results suggest that abolishing the surface tension of the alveolar lining layer removes support from parts of the blood-gas barrier when the capillaries are subjected to a high transmural pressure but that not all portions of the barrier are subjected to the same forces.

Animals↗

PubMed1995

Pulmonary microvascular permeability. Responses to high vascular pressure after induction of pacing-induced heart failure in dogs.

The pressure threshold for injury of pulmonary capillaries is approximately 50 to 55 cm H2O in the canine lung, as measured by changes in the filtration coefficient (Kf,c). Since the pulmonary endothelial basement membrane has been observed to thicken in patients with heart failure and pulmonary venous hypertension, we hypothesized that both baseline permeability and the threshold for high-vascular-pressure injury would be altered as a result. Dogs (n = 12) were chronically paced at 245 beats per minute for approximately 4 weeks, then were paced at 225 beats per minute for an additional 3 weeks. Lung lobes from anesthetized paced dogs and additional control dogs (n = 14) were then isolated, ventilated, and perfused with blood. Although vascular resistance was increased nearly threefold and vascular compliance reduced by 50% in the paced group, Kf,c referenced to 1 g blood-free dry weight was no different from control. Despite this lack of difference at normal pulmonary vascular pressures, several significant results were obtained. First, in the paced group there was a significant increase in the threshold for high-vascular-pressure injury: Kf,c measured at pulmonary vascular pressures commonly seen in heart failure (20 to 50 cm H2O) were significantly less in this group compared with control. Model predictions showed that in vivo, this difference in Kf,c would result in a 50% reduction in the amount of water and protein cleared across the pulmonary capillary endothelial barrier in the paced group.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1995

Pathogenesis of high-altitude pulmonary oedema: direct evidence of stress failure of pulmonary capillaries.

The pathogenesis of high-altitude pulmonary oedema (HAPE) is disputed. Recent reports show a strong correlation between the occurrence of HAPE and pulmonary artery pressure, and it is known that the oedema is of the high-permeability type. We have, therefore, proposed that HAPE is caused by ultrastructural damage to pulmonary capillaries as a result of stress failure of their walls. However, no satisfactory electron microscopy studies are available in patients with HAPE, and animal models are difficult to find. Madison strain Sprague-Dawley rats show a brisk pulmonary pressure response to acute hypoxia and are susceptible to HAPE. We exposed 13 Madison rats to a pressure of 294 torr for up to 12.5 h, or 4 rats to 236 torr for up to 8 h. Pulmonary arterial or right ventricular systolic pressures measured with a catheter increased from 30.5 +/- 0.5 (SEM) in controls (n = 4) to 48 +/- 2 torr (n = 11). The lungs were fixed for electron microscopy with intravascular glutaraldehyde. Frothy bloodstained fluid was seen in the trachea of three animals. Ultrastructural examination showed evidence of stress failure of pulmonary capillaries, including disruption of the capillary endothelial layer, or all layers of the wall, swelling of the alveolar epithelial layer, red blood cells (RBCs) and oedematous fluid in the alveolar wall interstitium, proteinaceous fluid and RBCs in the alveolar spaces, and fluid-filled protrusions of the endothelium into the capillary lumen.(ABSTRACT TRUNCATED AT 250 WORDS)

Altitude Sickness↗

PubMed1995

[Lymphatic metastasis in central direction and bowel axial direction in colonic cancers].

485 lymph nodes were founded by palpation in 44 R3 resected specimens of colonic cancers. In the bowel axial direction, the rate of lymphatic metastasis was 6.8%, which accound for 9.6% of the positive lymph node metastasis. All these positive nodes were limited from 10 cm proximal to 5 cm distal to the tumor. In the central direction, the rate of mesenteric lymphatic metastasis was 20.4%, and the rate of lymphatic metastasis at the root of mesentery was 4.5%, which accounted for 38.1% of the positive lymph node metastasis. Compared to the bowel axial direction, mesenteric lymphatic metastasis in the central direction was more common and should be carefully disseted during radical operation.

Adenocarcinoma↗

PubMed1995

[A study on factors of acupuncture methods affecting effects through acupuncture treatments for experimental gastric ulcer in rats].

Many factors, such as the selection of acupoints, the interval between acupunctures, the acupuncture time, the manipulation and the specification of acupuncture needles, are capable of affecting curative effects. There were some studies on these factors ago. However each of these studies only related to a single factor. These studies could not reflect the clinical truth, and could not provide accurate overall data for medical staff. In order to solve the above problems, we carried out an animal experiment designed by L9 (3(4)) orthogonal design. The experiment which consisted of 9 acupuncture groups and 3 control ones was carried out in 108 rats, which were suffered from experimental gastric ulcer. In the experiment, the body weight, ulcer area, plasma SOD and LPO of each rat were observed. The results showed that in the acupuncture treatments for experimental gastric ulcer in rats, 10 minutes' electric acupuncture treatment using thinner needles and the method that each rat was treated every other day were the best methods. The reason why the above results came into being was elucidated in this paper.

Acetates↗

PubMed1994

Refined crystal structure of mitochondrial malate dehydrogenase from porcine heart and the consensus structure for dicarboxylic acid oxidoreductases.

The crystal structure of mitochondrial malate dehydrogenase from porcine heart contains four identical subunits in the asymmetric unit of a monoclinic cell. Although the molecule functions as a dimer in solution, it exists as a tetramer with 222 point symmetry in the crystal. The crystallographic refinement was facilitated in the early stages by using weak symmetry restraints and molecular dynamics. The R-factor including X-ray data to 1.83-A resolution was 21.1%. The final root mean square deviation from canonical values is 0.015 A for bond lengths and 3.2 degrees for bond angles. The resulting model of the tetramer includes independent coordinates for each of the four subunits allowing an internal check on the accuracy of the model. The crystalline mitochondrial malate dehydrogenase tetramer has been analyzed to determine the surface areas lost at different subunit-subunit interfaces. The results show that the interface with the largest surface area is the same one found in cytosolic malate dehydrogenase. Each of the subunits contains a bound citrate molecule in the active site permitting the elaboration of a model for substrate binding which agrees with that found for the crystalline enzyme from Escherichia coli. The environment of the N-terminal region of the crystallographic model has been studied because the functional protein is produced from a precursor. This precursor form has an additional 24 residues which are involved in mitochondrial targeting and, possibly, translocation. The crystallographic model of mitochondrial malate dehydrogenase has been compared with its cytosolic counterpart from porcine heart and two prokaryotic enzymes. Small but significant differences have been found in the polar versus nonpolar accessible surface areas between the mitochondrial and cytosolic enzymes. Using least squares methods, four different malate dehydrogenases have been superimposed and their consensus structure has been determined. An amino acid sequence alignment based on the crystallographic structures describes all the conserved positions. The consensus active site of these dicarboxylic acid dehydrogenases is derived from the least squares comparison.

Amino Acid Sequence↗

PubMed1994

Structure of trichosanthin at 1.88 A resolution.

Trichosanthin (TCS) is one of the single chain ribosome-inactivating proteins (RIPs). The crystals of the orthorhombic form of trichosanthin have been obtained from a citrate buffer (pH 5.4) with KCl as the precipitant. The crystal belongs to the space group P2(1)2(1)2(1) with a = 38.31, b = 76.22, c = 79.21 A. The structure was solved by molecular replacement method and refined using the programs XPLOR and PROLSQ to an R-factor of 0.191 for the reflections within the 6-1.88 A resolution range. The bond length and bond angle in the protein molecule have root-mean-square deviations from ideal value of 0.013 A and 3.3 degrees, respectively. The refined model includes 247 residues and 197 water molecules. The TCS molecule consists of two structural domains. The large domain contains six alpha-helices, a six-stranded sheet, and an antiparallel beta-sheet. The small domain has a largest alpha-helix, which shows a distinct bend. The possible active site of the molecule located on the cleft between two domains was proposed. In the active site Arg-163 and Glu-160, Glu-189 and Arg-122 form two ion pairs, Glu-189 and Gln-156 are hydrogen bonded to each other. Three water molecules are bonded to the residues in the active site region. The structures of TCS molecule and ricin A-chain (RTA) superimpose quite well, showing that the structures of the two protein molecules are homologous. Comparison of the structures of the TCS molecule in this orthorhombic crystal with that in the monoclinic crystal indicates that there are no essential differences of the structures between the two protein crystals.

Amino Acid Sequence↗

PubMed1994

Comparative aspects of the strength of pulmonary capillaries in rabbit, dog, and horse.

In previous studies of rabbit and dog lung, we demonstrated stress failure of pulmonary capillaries at high transmural pressures (Ptm). The Ptm necessary to elicit stress failure was 40 cmH2O higher in dog than rabbit, and the total blood-gas barrier (BGB) thickness was greater in dog than rabbit. This suggests that stress failure may be related to BGB thickness, and is consistent with the Laplace relationship which states that wall stress is proportional to capillary radius but inversely proportional to wall thickness. In the present studies, we compared BGB thickness and an index of capillary radius in lungs from 3 rabbits, 3 dogs, and 2 horses perfusion fixed at a Ptm of approximately 30 cmH2O. Thicknesses of the BGB were measured at right angles to the barrier at random points on the capillary wall determined by test line intersections. Capillary radius was determined from the mean of major and minor axes measured on electron micrographs. Capillary pressure for failure in the horse was taken to be the mean of pulmonary arterial and left atrial pressures observed in galloping thoroughbreds known to develop exercise-induced pulmonary hemorrhage, although the actual pressure required for failure may be less than this. Average capillary radii were 3.6, 3.4, and 3.2 microns for rabbits, dogs, and horses, respectively. We found that the BGB was thinnest in the rabbit, intermediate in the dog, and thickest in the horse. Calculated capillary wall stress values for the median total BGB thickness at a nominal Ptm of 30 cmH2O were 2.5 x 10(4), 1.7 x 10(4), and 1.5 x 10(4) N.m-2 for rabbits, dogs, and horses, respectively. This species ranking fits with the pressures required to cause stress failure which are approximately 50, 90, and 130 cmH2O in rabbit, dog, and horse, respectively. We conclude that the differences in capillary radius of curvature and BGB thickness account for some of the observed differences in Ptm necessary to cause stress failure. However, other factors may also be important in determining the strength of the BGB.

Animals↗

PubMed1993

Clinical studies on the mechanism for acupuncture stimulation of ovulation.

Ovulatory dysfunction is commonly seen in gynecology clinic. It may cause infertility, amenia, functional uterine bleeding and a variety of complications. This research according to TCM theory records treating with acupuncture 34 patients suffering from ovulatory dysfunction. Changes in clinical symptoms and some relative targets are reported, plus findings in animal experiments. The effect of acupuncture in improving ovulation and the rationale are discussed. According to TCM theory concerning the generative and physiologic axis of women, this research involved the following points: Ganshu (UB 18), Shenshu (UB 23), Guanyuan (Ren 4), Zhongji (Ren 3), and Sanyinjiao (Sp 6). The reinforcement and reduction of acupuncture enables it to strengthen liver and kidney. Through the Chong and Ren channels it nourishes uterus to adjust the patient's axis function and recover ovulation. Treated on an average of 30 times, the patients' symptoms improved to varying degrees. The marked effective rate was 35.29%, the total effective rate being 82.35%. BBT, VS, CMS, and B ultrasonic picture all improved to some degree. The results also showed that acupuncture may adjust FSH, LH, and E2 in two directions and raise the progesterone level, bringing them to normal. The animal experiments confirmed this result. Results showed that acupuncture may adjust endocrine function of the generative and physiologic axis of women, thus stimulating ovulation. The results of this research will provide some scientific basis for treating and further studying this disorder.

Acupuncture Therapy↗

PubMed1992

Mortality and incidence of bladder cancer in benzidine-exposed workers in China.

We examined bladder cancer mortality and incidence to 1981 in 1,972 workers employed in benzidine-exposed jobs in Tianjin, Shanghai, and Jilin, China, between 1972 and 1977, and in 1,974 unexposed workers employed during the same time period. In comparison to general population rates, in the benzidine-exposed group the ratio of observed to expected deaths (SMR) was 17.5 (95% C.I.: 7.5-34.5) and the ratio of observed to expected incident cases (SIR) was 25.0 (95% C.I.: 16.9-35.7). No excess was noted in the unexposed group. The 25-fold increase in bladder cancer incidence in the exposed group was related to level of exposure, with the SIR rising from 4.8 for low exposure to 36.2 for medium exposure, and 158.4 for high exposure. Risks were elevated both for producers of benzidine (SIR = 45.7; 95% C.I.: 20.9-86.8) and for users (SIR = 20.9; 95% C.I.: 12.9-32.0) of benzidine dyes. Benzidine-exposed workers who smoked tobacco had a 31-fold risk (95% C.I.: 20.4-46.4), while non-smoking workers had an 11-fold risk (95% C.I.: 3.6-25.8), suggestive of a multiplicative relationship between these two carcinogens.

Air Pollutants, Occupational↗