Search PubMed⌕ Search

Biomedical subjects

H Song

Publications and source records attributed to H Song.

At least 217 records · Page 12Linked to original sources
PubMed1994

Neuro-pathophysio-biochemical profiles of neonatal asphyxia.

Neurological and neuroelectrophysio-biochemical profiles were evaluated in newborn lambs exposed to severe temporary asphyxia. Isoelectric EEG, marked disturbances of phosphorus magnetic resonance spectrum (31P-MRS), and significant brain intracellular acidosis (pHi) were noted during asphyxia. Following resuscitation, the presence of early postasphyxic blood-brain-barrier (BBB) opening was associated with a marked transient increase in intracranial pressure (ICP), a 50% neonatal mortality and a 67% incidence of severe asphyxic encephalopathy. In contrast, those lambs exposed to the same magnitude of asphyxia, but without early BBB opening experienced neither death nor severe neurological deficits. Further, these lambs showed a rapid progressive normalization of the 31P-MRS and pHi, despite, the lack of EEG recovery in the first hour following resuscitation. Thus, the present study depicts that the early postasphyxic BBB disruption following temporary neonatal asphyxia is associated with poor prognosis.

Acid-Base Equilibrium↗
PubMed1994

Lecompte procedure for complete transposition of the great arteries with ventricular septal defect and pulmonary stenosis.

From December 1988 to February 1993, 19 patients were treated by the Lecompte procedure for complete transposition of the great arteries associated with a ventricular septal defect and pulmonary stenosis. The mean age at operation was 3.1 +/- 0.8 years (mean +/- standard error). This technique consisted of resecting the outlet septum, constructing a tunnel that connected the left ventricle to the aorta, closing the proximal pulmonary arterial stump, pulling the distal pulmonary artery down to the right ventriculotomy site directly, and covering anteriorly with the fixed autologous pericardium. Operative mortality was 5.3%. The mean follow-up was 24.2 +/- 3 months, with no late death. One reoperation was performed because of residual right ventricular outflow tract obstruction. All survivors were studied by echocardiography at intervals of 6 months to 1 year. In all survivors (except for 1 child who underwent reoperation), the estimated pressure gradient between the right ventricle and the pulmonary artery, the structure of the left ventricular outflow tract, left ventricular function, and right ventricular contractility were all satisfactory.

Abnormalities, Multiple↗
PubMed1994

Preparation, characterization and application of monoclonal antibodies against PAI-1.

Six hybridoma cell lines (AP1-AP6) secreting monoclonal antibodies (McAb) against PAI-1 were obtained by fusing the murine myeloma cell line SP2/0 with the spleen cells from Balb/c mouse immunized with recombinant PAI-1 expressed in E. coli. These antibodies were purified by SPA affinity chromatography. All McAbs recognized rPAI-1 and PAI-1 from the human hepatoma cell line HepG2. The titers of ascites were more than 10(6). The antibody-antigen affinity constants (Kaff) for anti-PAI-1 McAb measured by EIA were between 3.45 x 10(7)-1.05 x 10(10) M. AP2 and AP3 McAbs were effective in quenching the activity of PAI-1. Partial quenching of PAI-1 activity was achieved with AP4, AP5 and AP6 McAbs respectively. AP1 McAb had no effect upon PAI-1 activity. Three of the six McAbs (AP1, AP4 and AP5) bound to the PAI-1/t-PA complex, while the others did not. The PAI-1 was purified 51 folds to homogeneity from serum free medium of HepG2 with the recovery rate of 92% by one-step procedure using Sepharose 4B conjugated with anti-PAI-1 McAb (AP1, AP3 and AP4). A sandwich ELISA for the measurement of PAI-1 antigen in human plasma was developed, based on anti-PAI-1 McAb against non-overlapping epitopes. The mean value of plasma PAI-1 for the healthy donors was 24.7 +/- 7.75 ng/ml measured by ELISA.

Animals↗
PubMed1994

[Using ELISA to evaluate the serologic and epidemiologic effect following rabies vaccination].

After vaccinating the people bitten by animals against rabies, we have examined their serum antibodies by using ELISA. One year later, we sent a mail to everyone of them inquiring if he had contracted rabies. The response rate was 85%. The case fatality rate of the positive antibody group was 0.24% (1/415). The case fatality rate of the negative antibody group was 3.16 (3/95). It showed that there was significant difference in the case fatality rate of rabies between the two groups, (P = 0.022). The dead person of the positive antibody group was bitten on his cheek by a rabid dog. He had not cleaned his wound. He had received 6 injections of rabies vaccines. His incubation period was 28 days. The P/N of serum antibody on the 28th day was 3.27.

Adult↗
PubMed1993

Selective detection of chlorine-containing compounds by gas chromatography/chemical reaction interface mass spectrometry.

Chemical reaction interface mass spectrometry (CRIMS) was studied as a gas chromatographic detection technique for chlorine-containing compounds. Both SO2 and HBr were tested as reactant gases. With SO2, a detection limit of 50 pg of diazepam and a linear range of 4 orders of magnitude were achieved, and the experimental data were reproducible. With HBr, the detection limit was 10 ng of diazepam and the linear dynamic range was only 2 orders of magnitude. The possible pharmacological application of CRIMS was studied using urine spiked with diazepam and several of its metabolites, and the results show CRIMS to be a simple but potentially powerful method in drug metabolism studies.

Acids↗
PubMed1993

Toxicological investigations on silicon carbide. 1. Inhalation studies.

The question of lung damage as a result of exposure to silicon carbide (SiC) was investigated by inhalation experiments to obtain information on the qualitative response of lung tissue to the test substance (SiC). For comparison, quartz, kaolinite, and tempered clay dusts were used. The indices for the effects of the dusts studied were organ weights, numbers of bronchoalveolar cells, lung surfactant phospholipid concentrations including subfractions, and lung clearance. Exposure to the test samples was carried out according to the Essen inhalation model in two independent series. The results of the two series were similar: Compared with sham controls, exposure to SiC did not affect the indices studied. Even at a low dose (a quarter of the SiC dose) quartz gave pronounced deviations in all indices. In particular, an increase in granulocytes indicated toxic properties of the dust. The long term elimination of quartz from the lung was worse than that of SiC. The kaolinite and tempered clay dusts were intermediate between SiC and quartz based on several of the indices studied. It is concluded that SiC is deposited practically inert in the lung.

Administration, Inhalation↗
PubMed1993

Evidence for sensing and integration of biological signals by the capillary network.

The aim of this study was to explore the phenomenon first described by Dietrich (Microvasc. Res. 38: 125-135, 1989) in which a local application of norepinephrine (NE) on a capillary can temporarily reduce flow via constriction of the feeding arteriole. Our objectives were to show that this phenomenon of remote response is not limited to vasoconstriction, can be elicited by materials other than NE, shows stimulus-strength dependency, and can be integrated within the capillary network. We used an intravital micropharmacological approach to iontophoretically apply (in mM concentrations in the pipette) NE, acetylcholine (ACh), 5'-N-ethylcarboxamidoadenosine (NECA, adenosine analogue), K+, and H+ on capillaries of the frog sartorius muscle in situ. Responses were measured in terms of changes in velocity of red blood cells (VRBC) in capillaries or in terms of changes in arteriolar diameter. ACh (3 mM) caused significant increases in diameter (from 34 to 37 microns) and in VRBC (from 250 to 340 microns/s, i.e., 36%). NE (3 mM) reduced VRBC by 16%. The magnitude of ACh and NE velocity responses increased with increasing pipette concentration and with increasing iontophoretic current. The ACh response was blocked by a local pretreatment with atropine. NECA, K+, and H+ caused 20-40% increases in VRBC. Dual application of NE on two capillaries fed by the same arteriole resulted in a greater VRBC reduction than for single NE application. Dual application of NE and ACh significantly attenuated the ACh response.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗
PubMed1992

The pyruvate dehydrogenase complex from the parasitic nematode Ascaris suum: novel subunit composition and domain structure of the dihydrolipoyl transacetylase component.

The pyruvate dehydrogenase complex (PDC) from muscle of the adult parasitic nematode Ascaris suum plays a unique role in its anaerobic mitochondrial metabolism. Resolution of the intact complex in high salt dissociates the pyruvate dehydrogenase subunit but leaves the dihydrolipoyl dehydrogenase subunit (E3) and two other proteins with apparent M(r)s of 45 and 43 kDa bound to the dihydrolipoyl transacetylase (E2) core. These proteins are not observable on Coomassie brilliant blue-stained gels of other eukaryotic PDCs, but the 45-kDa protein is similar in apparent M(r), pI, and sensitivity to trypsin to the Kb subunit of the bovine kidney PDH alpha kinase. Acetylation of the ascarid PDC with [2-14C]pyruvate under conditions designed to maximize the incorporation of label into protein yielded only a single radiolabeled subunit, E2. These results confirm earlier reports that the ascarid PDC lacks protein X, an integral component recently identified in other eukaryotic PDCs. About 1.6 to 1.8 mol of 14C was incorporated/mole of E2, suggesting that the ascarid E2 contained two lipoly-bearing domains. Domain mapping of the 14C-acetylated ascarid E2 by limited tryptic digestion identified two lipoyl-bearing fragments with apparent M(r)s of 50 and 34 kDa and two core fragments with apparent M(r)s of 46 and 30 kDa. The ascarid E2 domain structure appears to be similar to that of other E2s. However, it appears that the subunit-binding domain (E2B) of the ascarid E2 may be significantly larger or be flanked by larger than normal interdomain regions. An enlarged E2B domain may be necessary to accommodate the additional binding of E3 to the E2 subunit in the ascarid complex, in the absence of protein X.

Acetyltransferases↗
PubMed1992

[Screening and distinguishing heavy chain variable region genes of McAb against encephalitis type B virus].

In order to prepare human-mouse chimeric antibody against encephalitis type B virus, hybridoma 51-8 cells secreting monoclonal antibody against the virus were used as material for isolating heavy-chain variable region gene of the McAb. High molecular weight DNA of the hybridoma cell was partially digested by BamHI, and then constructed a gene library containing 2 x 10(7) pfu with lambda EMBL-3 as vector. With cDNA of heavy-chain variable region of the monoclonal antibody as probe, nine positive plaques were screened from 360,000 plaques, which have been proven that they contained a fragment of heavy-chain variable region genes by dot hybridization and Southern hybridization. Four recombinants among the nine positive plaques were further distinguished with J11 probe containing J3, J4 and heavy-chain enhancer. After cutting by EcoR1, there was a 3.8 kb fragment in three recombinants as similar to that in liver cell and Sp2/0 cell, but not in the fourth recombinant (lambda 8a4) which contained a 4.5 kb fragment that did not present in liver cell and Sp2/0 cell. The results showed that the inserts in former 3 recombinants were non-rearranged fragment of heavy-chain variable region genes, but the insert in lambda 8a4 contained a rearranged functional variable region gene. The 4.5 kb fragment could not be hybridized with a probe containing J1 and J2, but contained VH, J3 or/and J4 and enhancer, that further proved it was a functional variable region gene. Therefore, the 4.5 kb fragment was isolated and subcloned in pUC 19, and its physical map was made.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

[Chromosome polymorphism in five hydatidiform moles].

Five hydatidiform moles were karyotyped and their genetic origins were investigated using chromosome polymorphisms. 4 cases of complete mole were diploid, homozygous, female, androgenetic in origin. 1 case of partial mole was triploid, 69, XXY and with a chromosomal contribution from the female gamete.

Diploidy↗
PubMed1990

[Ion-paired high performance liquid chromatographic determination of mitoxantrone hydrochloride injection].

Mitoxantrone (DHAQ) is a new anti-cancer agent. The ion-pair HPLC method to determine mitoxantrone hydrochloride injection was proposed. Mitoxantrone can be separated on Zorbax-ODS column with methanol-water-formic acid (450:50:1.5) containing 3.605g SDS as mobile phase. The pH of mobile phase was adjusted to 2.7. The flow rate was 1.0 ml/min and detection was at wavelength of 254 nm, providing a detection limit of 1ng (r/n, 3:1) of DHAQ. DHAQ was determined by peak area measurement with ametantrone as internal standard. The rectilinear calibration graph in the range of 1-10 micrograms of DHAQ was obtained (r = 0.999 2). The average recovery was 99.62 +/- 2.36% (n = 10), and the results were not interfered by the other ingredients in the injection.

Chromatography, High Pressure Liquid↗
PubMedDate not supplied

The spatial relationship between infant mortality and birth defect rates in a U.S. city.

The spatial patterns of infant mortality and birth defect rates in the Des Moines, Iowa, urban region are described as a contoured surface based on the punctual kriging of address-matched vital statistics records from The Iowa Department of Public Health. Areas defined as having high rates are shown to be sensitive to the size of the spatial filtering units. There is no correlation between infant mortality and birth defect rates in the region. The significance of areas with high rates is determined by a Monte Carlo simulation procedure. One area of high infant mortality is found in the region, which contrasts with many smaller areas with high birth defect rates in the region. The observed birth defect rate pattern is consistent with the hypothesis that each birth was equally likely to result in a birth defect, while the infant mortality pattern is unlikely to be the result of such an equal likelihood process.

Congenital Abnormalities↗