Search PubMed⌕ Search

Biomedical subjects

G Song

Publications and source records attributed to G Song.

At least 55 records · Page 3Linked to original sources
PubMed2000

[Cardiac allograft arteriosclerosis and myocardial necrosis].

OBJECTIVE: To study the development of myocardial necrosis, fibrosis, and arteriosclerosis in cardiac allograft in order to provide a theoretical basis for the prevention and treatment of anti-rejection. METHODS: The recipient was pretreated with inoculation of donor splenocytes (SPC) followed by cyclophosphamide (CP). Heterotopic cervical heart transplantation was performed. The allografts stained with Hematoxylin and eosin (HE), Masson and Van Gieson were studied about inflammatory cell infiltration, myocardial necrosis, fibrosis and arteriosclerosis. RESULTS: Preconditioning with SPC followed by CP prolonged the survival time of cardiac allograft. Inflammatory cell infiltration, myocardial necrosis, fibrosis, and arteriosclerosis in cardiac allograft were significantly decreased. CONCLUSIONS: The development of acute cardiac allograft rejection originated from the epicardial area to the intimal area of the heart in rat. The infiltration of collagenous fiber in the coronary arteries is one of the major causes of concentric stenosis. The pretreatment of SPC followed by CP can prevent and relieve the rejection.

Animals↗
PubMed2000

[Assay and L1 gene sequence analysis of human papillomavirus type 6 and 11 in condylomata acuminata].

OBJECTIVE: To determinate the prevalence of HPV type 6, 11 in condylomata acuminata, and analyze the sequence of L1 gene and its deduced L1 protein. METHODS: PCR was used to amplify DNA sequences between E6 and E7 of HPV type 6 and 11. The PCR products were identified by the fragment length cleaved with restriction enzyme RsaI. L1 genes were amplified with high fidelity Taq, and cloned DNA sequences were detected by the dideoxynucleotide method. RESULTS: In 34 examples of condylomata acuminata, HPV11 was found in 25 examples (73.5%), HPV6 in 15(44.1%), including HPV6 + HPV11 in 6(17.6%). In comparison with the prototypes there were 7-8 point mutations in HPV11 L1 gene and 3 in HPV6L1 gene. L1 encoded protein changes showed up only in 1-3 amino acids in the former cases. CONCLUSION: Most of patients tested with condylomata acuminata are mainly infected by HPV11, the rest of them by HPV6 or by co-infection of two mixex types. Sequence analysis of L1 genes indicated that mutations were found in both HPV6 and 11, whereas deduced amino acid mutations in L1 protein were limited in HPV11 only.

Adult↗
PubMed2000

[Synthesis and DNA binding studies of Ruthenium complexes by spectra].

New Complexes Ru(bpy)2dppx2+ were synthesized. The binding of Ru(bpy)2dppx2+ to calf thymus DNA has been investigated by using electronic absorption and fluorescence spectra. The intercalation mode was proved to exist. The DNA leads to a dramatic enhancement of the photoluminescence of the drug at 599 nm (lambda ex = 471 nm) and absorption hypochromic effect and red shift. It was obvious that Ruthenium complexes may be used at a good DNA probe.

Animals↗
PubMed1999

Increased protein kinase C activity and expression of Ca2+-sensitive isoforms in the failing human heart.

BACKGROUND: Increased expression of Ca2+-sensitive protein kinase C (PKC) isoforms may be important markers of heart failure. Our aim was to determine the relative expression of PKC-beta1, -beta2, and -alpha in failed and nonfailed myocardium. METHODS AND RESULTS: Explanted hearts of patients in whom dilated cardiomyopathy or ischemic cardiomyopathy was diagnosed were examined for PKC isoform content by Western blot, immunohistochemistry, enzymatic activity, and in situ hybridization and compared with nonfailed left ventricle. Quantitative immunoblotting revealed significant increases of >40% in PKC-beta1 (P<0.05) and -beta2 (P<0.04) membrane expression in failed hearts compared with nonfailed; PKC-alpha expression was significantly elevated by 70% in membrane fractions (P<0.03). PKC-epsilon expression was not significantly changed. In failed left ventricle, PKC-beta1 and -beta2 immunostaining was intense throughout myocytes, compared with slight, scattered staining in nonfailed myocytes. PKC-alpha immunostaining was also more evident in cardiomyocytes from failed hearts with staining primarily localized to intercalated disks. In situ hybridization revealed increased PKC-beta1 and -beta2 mRNA expression in cardiomyocytes of failed heart tissue. PKC activity was significantly increased in membrane fractions from failed hearts compared with nonfailed (1021+/-189 versus 261+/-89 pmol. mg-1. min-1, P<0.01). LY333531, a selective PKC-beta inhibitor, significantly decreased PKC activity in membrane fractions from failed hearts by 209 pmol. min-1. mg-1 (versus 42.5 pmol. min-1. mg-1 in nonfailed, P<0.04), indicating a greater contribution of PKC-beta to total PKC activity in failed hearts. CONCLUSIONS: In failed human heart, PKC-beta1 and -beta2 expression and contribution to total PKC activity are significantly increased. This may signal a role for Ca2+-sensitive PKC isoforms in cardiac mechanisms involved in heart failure.

Adolescent↗
PubMed1999

Changes in blood pressure, body mass index, and salt consumption in a Chinese population.

BACKGROUND: The prevalence of hypertension among the population of Tianjin is one of the highest in China. We attempted to assess the changes in blood pressure, body mass index, and salt consumption in Tianjin from 1989 to 1996. METHODS: Two independent cross-sectional population surveys with the representative samples of 14,046 persons in 1989 and 2,000 persons in 1996 were carried out in Tianjin. A salt surveillance system was established with four salt consumption surveys (in 1992, 1993, 1994, and 1996) to estimate the changes in salt consumption at the household level. RESULTS: From 1989 to 1996, the prevalence of hypertension and obesity decreased among people aged 45-64 years in both genders. Mean systolic blood pressure decreased significantly in women and leveled off in men. Diastolic blood pressure increased significantly. Body mass index remained unchanged. The unfavorable trends were mainly attributable to the negative changes in younger people (15-34 years) in both genders. There were no changes in salt consumption between 1992 and 1996 at the house level. CONCLUSIONS: There was a favorable development in prevalence of hypertension and obesity among individuals in the age group of 45-64 years in the study population. Health education needs to pay more attention to young people.

Adolescent↗
PubMed1999

PKC translocation without changes in Galphaq and PLC-beta protein abundance in cardiac hypertrophy and failure.

Activation of protein kinase C (PKC) has been implicated as playing a key role in the pathogenesis of cardiac hypertrophy. This study investigates the response of several signal transduction proteins responsible for PKC activation during the transition from compensated pressure-overload hypertrophy (POH) to congestive heart failure (CHF). Pressure overload was produced on male, adult, Hartley strain guinea pigs using a ligature around the descending thoracic aorta. Sham-operated controls, POH, and CHF groups were identified based on left ventricular hypertrophy, pulmonary congestion, and isolated heart Langendorff mechanics. Quantitative immunoblotting revealed phospholipase C (PLC)-betaI and Galphaq were unchanged during POH and CHF, as were RGS2, RGS3, and RGS4 (regulators of G protein signaling, which are activators of intrinsic GTPase activity). Translocation of PKC-alpha, -epsilon, and -gamma from cytosolic to membranous fractions were significantly increased during POH and CHF. Cytosolic PKC activity was also elevated during POH. We conclude that differential PKC activation may be mediated by increases in Galphaq and PLC-betaI activity rather than upregulation of expression.

Animals↗
PubMed1999

[Identification of mutations in the human EXT1 and EXT2 genes].

OBJECTIVE: To investigate further the genetic basis of hereditary multiple exostoses (EXT) and provide useful information for gene diagnosis of the disease. METHODS: Polymerase chain reaction-single strand conformation polymorphism was used to examine the entire coding regions of EXT(1) gene on chromosome 8 and EXT(2) gene on chromosome 11 for mutation in thirty EXT families. Mutations were further identified by sequencing. RESULTS: Two frameshift mutations were identified in two unrelated EXT families. One was the deletion of one base(T) in exon 6 of the EXT(1) gene, and the other was the deletion of four bases (tgtt) in exon 2 of the EXT(2) gene. Both of the mutations resulted in a frameshift and premature termination of translation. CONCLUSION: EXT is a genetically heterogeneous bone disorder caused by the mutation of EXT tumor suppressor gene. These results could be directly applied in the genetic counseling and prenatal genetic diagnosis of EXT.

Chromosome Deletion↗
PubMed1999

[Investigation on the adhesive properties of different cycle hepatoma cells].

OBJECTIVE: To study the adhesive forces of HTC cells on different concentration of artificial basement membrane (collagen IV coated)and synchronous G1&S phase HTC cells on a certain concentration of artificial basement membrane. METHODS: The adhesive forces of HTC cells were investigated by micropipette aspiration technique. The synchronous G1 and S phase cells were achieved through thymine-2-desoryriboside and cochicine sequential blockage method and double thymine-2-desoryriboside blockage method respectively. RESULTS: HTC cells with 72.10% of G1 phase and 98.94% of S phase were achieved through thymine-2-desoryriboside and cochicine sequential blockage method and double thymine-2-desoryriboside blockage method respectively. The adhesive force of HTC cells on artificial basement membrane was in direct proportion to the concentration of collagen IV. G1 phase HTC cells had higher adhesive forces than S phase cells. CONCLUSION: These studies suggested that the increase of basement membrane might be conducive to the chemotactic motion and adhesion of tumor cells; G1 phase cells were more capable of adhering to and getting through basement membrane than S phase cells, and reflected the differences of receptors between G1 phase cells and S phase cells.

Animals↗
PubMed1999

Effects of oxidative damage of membrane protein thiol groups on erythrocyte membrane viscoelasticities.

In three oxidative damaging systems: the diamide-mercaptoethanol redox modification system (DM), the pyrogallol oxygen free radicals system (PG) and the hypoxanthine-xanthine oxidase oxygen free radical system (HXO), the effect of erythrocyte membrane oxidative damage on membrane viscoelasticities was investigated with micropipette aspiration method. The experimental results indicated that erythrocyte membrane oxidative damage has a great influence upon the membrane mechanical properties. The oxidative damage led to decrease of contents of membrane protein thiol radical. The scanning of SDS-PAGE presented that membrane proteins form the higher molecular weight component (HMP) by the cross-linking of membrane protein thiol radicals that might hinder the conformational change of membrane protein. This might be the reason for the increased membrane elastic modulus and viscous coefficient upon treating erythrocytes with the oxidative damaging systems. A significant negative logarithm regression relation was found between the membrane elastic modulus, mu, or viscoefficient, eta, and the contents of membrane protein thiol radicals. These experimental results suggested that thiol radicals oxidative damage reaction due to the superoxides anions (*O2-) may be an important molecular mechanism inducing changes of membrane viscoelasticities or whole cell deformability of erythrocyte under physiological and pathological oxidative stress.

Blood Viscosity↗
PubMed1999

Epidemiological progresses of hemorrhagic fever with renal syndrome in China.

PURPOSE: To summarize the major achievements of Chinese work on the epidemiology and prevention of hemorrhagic fever with renal syndrome (HFRS) in recent years, and to give a general review on the present situation of HFRS in China. DATA SOURCES: Reviews and papers published in Chinese journals, relevant to the objectives, written or collected by the author; and the research work of the author. STUDY SELECTION: An outline was drafted according to the purpose given above, and the relevant materials and data were grouped together into different items outlined. DATA EXTRACTION: All the materials and data extracted were published or specially assessed. RESULTS: HFRS was first recognized in the northeastern China in 1931. It has been found prevalent also in many other parts of China since 1955, and presently, 28 out of 31 provinces (autonomous regions, or municipalities) have been proved to be its endemic areas. The total number of cases is 1,256,431 from 1950 to 1997, with 44,304 death (3.53%). 50-100 thousands of cases could be registered annually since 1981 when the presence of the Rattus-type HFRS was first identified serologically in China, with the highest peak in 1986 (115,985 cases). Three types of endemicity have been differentiated: the Apodemus-type, the Rattus-type and the mixed type of the two, by their peculiar seasonal distributions of cases and by methods of serotyping (HI, MAbs serotyping kits). The epidemiologic features of the Rattus-type HFRS are quite different from that of the Apodemus-type. 67 species of vertebrates were found to harbor hantavirus antigen or antibodies, but the chief or primary reservoir hosts are Apodemus agrarius and Rattus norvegicus only. Besides the commonly recognized enzootic mode of transmission (via contacts with the reservoir rodents or their excreta), mite transmission (including certain species of gamasid mites, and chigger mites) has been identified as the potential vectors and reservoir hosts with HFRS. Vertical transmission had been found in pregnant patients with HFRS, and in all three chief host rodents (Apodemus agrarius, Rattus norvegicus, the laboratory rats). The relatively high inapparent infection rates in the population of endemic areas of the Rattus-type HFRS after big outbreaks (8%-20%) are suggested to play a significant role in the gradual decline of the incidence of HFRS in that areas. Three kinds of inactivated vaccines against HFRS (the golden hamster kidney cell vaccine, the Mongolian gerbil kidney cell vaccine and the purified suckling mouse brain vaccine) have been successively developed and proved highly effective in the prevention of HFRS. CONCLUSION: Chinese workers on the epidemiology and prevention of HFRS in China have accomplished great achievements since 1981. As the relatively high annual incidence of HFRS sustained in recent years, control measures have to be reinforced. Many problems of HFRS and hantavirus infections are still not well understood or unclear, such as the poly-host nature, and the multi-modes of transmission, the natural history of hantaviruses and their genetic variation occurred in nature etc. The task for effective control of HFRS and the research on its epidemiology in China should be held on a high priority.

Animals↗
PubMed1999

[Adhesion of hepatocellular carcinoma cells to collagen IV coated surfaces].

OBJECTIVES: To quantitatively describe the adhesion of hepatocellular carcinoma (HCC) cells and hepatocytes to collagen IV/laminin coated surfaces and to investigate the relevance of cell adhesion forces to the coating concentration of collagen IV and, when laminin was co-coated along with collagen IV, the incorporation concentration of laminin. METHODS: A stepwise coating protocol was adopted to prepare the collagen IV/laminin coated surfaces, in which poly-D-lysine and collagen IV/laminin were successively coated onto glass surfaces and finally, bovine serum albumin was used to block the non-specific adhesion. Cell adhesion forces were measured by means of micropipette aspiration technique. RESULTS: Cell adhesion forces showed good dependence on the coating concentration of collagen IV. However, the amplitude for the increase of adhesion forces of HCC cells (202 x 10(-10) N, 26%) was far more less than that for hepatocytes(1,566 x 10(-10) N, 742%) when coating concentration increased from 1 microgram/ml to 5 micrograms/ml. No further increase in the adhesion forces of HCC cells was observed when the coating concentration of collagen IV increased beyond 2 micrograms/ml. The incorporation of laminin along with 2 micrograms/ml collagen IV did not readily result in an increase in the adhesion forces of the two kinds of cells to the surfaces. Among the concentration of laminin tested, only in certain concentration(0.625 microgram/ml or 1.25 micrograms/ml) did the incorporation of laminin along with 2 micrograms/ml collagen IV lead the adhesion forces of hepatocytes and HCC cells to the coated surfaces to reach their corresponding maximum values, otherwise this incorporation led the adhesion forces to decrease. CONCLUSION: The present method is efficient in investigating cell-matrix adhesion. The cell adhesion behavior to collagen IV for HCC differs obviously from those for normal hepatocytes. Laminin might be an important factor for the regulation of cell adhesion forces to matrix components.

Carcinoma, Hepatocellular↗
PubMed1999

[Preliminary study on the immune response in C57BL/6 mice vaccinated by nucleic acid encoding paramyosin of Chinese S. japonicum].

OBJECTIVE: To study the characteristics of immune response in C57 BL/6 mice by nucleic acid encoding full-length paramyosin of Chinese S. japonicum. METHODS: Total RNA was isolated from adult Chinese S. japonicum using TRIzol reagent. The full-length cDNA encoding paramyosin of Chinese S. japonicum was amplified by RT-PCR and cloned into expression vector pcDNA/Amp (pCMV-SjC97), which was intramuscularly injected into C57 BL/6 mice. The mice were vaccinated with DNA the three-week interval for a total of three inoculations. The specific anti-SjC97 IgM, IgG and IgE antibodies and IgG subclasses were determined by ELISA test. RESULTS: The pCMV-SjC97 vaccine induced specific anti-SjC97 IgM and IgG antibodies. The antibody response correlated well with the administered amount of pCMV-SjC97. The IgG subclasses, predominantly IgG2a and IgG2b, were observed in the mice vaccinated with pCMV-SjC97, but no IgG1 and IgG3 responses were seen. CONCLUSION: The strong immune response, especially Th1 type, can be induced in the mice with pCMV-SjC97 vaccine.

Animals↗
PubMed1999

[Clinical analysis of orbital cysticercus cellulosae].

OBJECTIVE: To investigate the clinical features, laboratory tests, medical imaging manifestations, diagnosis and treatment of orbital cysticercus cellulosae. METHODS: 23 cases of orbital cysticercus cellulosae were analyzed from 1973 to 1997. RESULTS: Most cases had features of exophthalmos, lid swelling, limitation of ocular movement. Some of them with visual loss, optic papilledema and orbital mass. B-scan ultrasonography revealed a cystic tumor and a strong echo spot with spontaneous movement. On CT scanning, found was a well-defined hyperdensity mass in which there was a low density area. On MRI, the signal intensity of T(1)WI of cystic fluid was low or moderate and of T(2)WI was high, while the signal intensity of T(1)WI and T(2)WI of surrounding scar tissue was still low. CONCLUSION: We can make diagnosis by imaging tests and treat them with surgical operations.

Adolescent↗
PubMed1999

[Research on the oncogenesis of cervical epithelial cells co-induced by human papillomavirus and human cytomegalovirus].

OBJECTIVE: The carcinogenesis of the human cervical carcinoma is known closely associated with human papillomavirus (HPV). The purpose of this article is to identify whether another sexually transmitted factor, human cytomegalovirus (HCMV) plays as a co-factor role in the carcinogenesis. METHODS: Human cervical epithelial cells immortalized by HPV16 were transfected with IE gene of HCMV. The condition and efficiency of IE gene were examined. RESULTS: It was showed that the cervical epithelial cells could be completely transformed into malignant by HPV 16 and IE gene of HCMV and tumor was formed by injecting the transformed cells in nude mice. CONCLUSION: The co-operation effect of HPV and HCMV auailed the oncogenesis of human cervical carcinoma and moreover, the cellular and molecular biological mechanism was discussed.

Animals↗
PubMed1999

[Studies on respiratory phase switching effects of Bötzinger complex].

The effects of electrical stimulation of Bötzinger complex (Bot.C) on respiratory rhythm were investigated in 40 urethane anesthetized adult rabbits. The results were as follows. (1) A short train stimulation delivered in the early inspiratory phase produced a transient inhibition of phrenic discharge. The stimulus, when delivered in the mid or late inspiratory phase, could cause a premature termination of the inspiratory phase ("inspiratory off-switch") and a switching to the expiratory phase, which was accompanied with the reduced duration of the consecutive expiratory phase. There was a negative linear correlation between the threshold intensity of inspiratory off-switching and delivery time of stimulation. (2) A short train stimulation delivery in the expiratory phase elicited a transient phrenic discharge. The discharge in the late expiratory phase was followed by a premature onset inspiration. This effect was also dependent on the strength and delivery time of the stimulus. The results suggest that the Bot.C is involved in the central control of respiratory phase-switching.

Animals↗
PubMed1999

[Stress-adaptation of bone].

Loading mechanotransduction sensors on the membrane of bone cells or osteoblasts can improve bone mechanisms and influence second messages, growth factors, bone matrix and oncogenes. The response of bone to stree is preportion to the magmititude of the stress. Stress-adaptation of bone is related with the magnititude, perporties, frequency time of stress.

Adaptation, Physiological↗
PubMed1999

[Induction of protective immunity in mice against Schistosoma japonicum by nucleic acid vaccine encoding the full-length paramyosin].

AIM: To investigate the immune efficacy of nucleic acid vaccination in mice against full-length paramyosin of Chinese Schistosoma japonicum. METHODS: C57BL/6 and BALB/c mice were vaccinated intramuscularly with the nucleic acid vaccine (pCMV-SjC97) encoding the full-length gene of paramyosin of Chinese S. japonicum. Each group was immunized three times at weeks 0, 3 and 6. Mice vaccinated with pCMV blank vector served as negative control. Mice were challenged three weeks after final DNA boosting by percutaneous infection with cercariae. Six weeks after infection the mice were perfused, worm burden and eggs in the livers, spleens and intestines were counted. Sera from vaccinated mice were collected from the tail vein at weeks 0, 3, 6 and 9, respectively. RESULTS: C57BL/6 mice vaccinated with pCMV-SjC97 produced predominantly IgG2a and IgG2b; whereas in BALB/c mice, IgG1, IgG2a and IgG2b antibodies. Immunization with the pCMV-SjC97 in C57BL/6 mice could confer significant worm reduction rate (35.5%-41.4%, P < 0.05) and egg reduction rate (liver: 44.5%-59.6%, P < 0.05; spleen: 56.7%-82.4%, P < 0.05; intestines: 57.9%, P < 0.05), but not in BALB/c mice. CONCLUSION: The nucleic acid vaccine, pCMV-SjC97, could induce protective immunity in C57BL/6 mice significantly.

Animals↗