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Biomedical subjects

H Song

Publications and source records attributed to H Song.

At least 163 records · Page 9Linked to original sources
PubMed1998

[Direct vision mitral valve reconstruction: a long-term follow-up of 46 cases].

OBJECTIVE: To improve the long-term results of direct vision mitral valve reconstruction. METHOD: From July 1983 through July 1995, 46 patients with mitral valve disease were treated by a direct vision reconstructive techniques. Rheumatic valve stenosis and incompetence were noted in 39 (patients), nonrheumatic insufficiencies in 5, and congenital disease in 2. According to leaflet pliability, type I normal leaflet motion was notedin 17 patients, type II leaflet prolapse in 3 and type III restricted leaflet motion in 29. Cardiac function (NYHA classification) showed class II in 2, class in 25 III, and class IV in 19. Valvuloplasty and annuloplasty were performed with various techniques according to the pathanatomical changes of the valve. Prosthetic obturators self made were employed in 29 patients. RESULT: The operative mortality rate was 6% (3/46). In the mitral valve replacement group it was 10% (27/265). Two to 10 years (mean 65 months) follow-up showed grade I cardiac function in 6 patients, grade II in 17, grade III in 8, and grade IV in 3. CONCLUSION: Good long-term results can be achieved by valve reconstruction with lower mortality and incidence of thromboembolism than.

Adolescent↗
PubMed1998

[Inhibitor of plasminogen activator 1 (PAI-1) in hepatocellular carcinoma].

OBJECTIVE: To study the expression of the type-1 inhibitor of plasminogen activator (PAI-1) on protein and mRNA in hepatocellular carcinoma (HCC), and the relation between PAI-1 and biological behaviour of HCC. METHOD: The tumor specimens of HCC (n = 48) and benign liver tumor (contorl n = 12) were tested by immunohistochemistry for the expression of PAI-1 protein. The tumor specimens of HCC (n = 20) and normal liver tissue (contorl n = 5) were evaluated by Northern blot analysis for the expression of PAI-1 mRNA. RESULT: PAI-1 protein and PAI-1 mRNA were higher in tumor cell than in the marginal tissue of tumor and in control (P < 0.01 and P < 0.05). In deaths 2 years after surgery, PAI-1 was increased as compared to the survival group (P < 0.05). When negative PAI-1 conupared with positive urokinase-type plasminogen activator (uPA) and positive uPA receptor (uPAR). The nambeigs invasion case increased, the difference was more significant than that in the group with negative PAI-1, uPA and uPAR (P = 0.039). CONCLUSION: The expression of PAI-1 protein and PAI-1 mRNA is increased in HCC. PAI-1 contributes to the invasion, metastasis and prognosis of HCC.

Blotting, Northern↗
PubMed1998

[Influence of alum on intestinal flora in mice].

OBJECTIVE: To observe the influence of alum on the intestinal microecological balance in normal microorganisms. METHOD: The mice were administered orally with alum of a small dosage(0.25/kg) and a large dosage(1 g/kg) for half a month, two months and three months, and a micro flora analysis of the mice was carried out at intervals of the above mentioned administrations. RESULT: The intestinal flora in the animals administered with alum was imbalanced. The counts of bifidobacteria and lactobacilli closely related to human physiological activities were decreased. The counts of pathogenic E. Coli significantly increased; and the longer the animals were treated with alum, the stronger the microecological balance was influenced. CONCLUSION: Alum could induce imbalance of the normal intestinal flora in mice.

Alum Compounds↗
PubMed1998

[Relationship between T-lymphocyte subpopulation and soluble interleukin-2 receptor (SIL-2R) in recurrent herpetic keratitis].

This article is to study the relationship between T-lymphocyte subpopulation and soluble interleukin-2 receptor (SIL-2R) in recurrent herpetic keratitis. We detected the T-lymphocyte subpopulation of peripheral blood and soluble interleukin-2 receptor(SIL-2R) in 30 cases of recurrent herpetic keratitis, 25 cases of healthy people were set as contrast. The results showed that there were obvious decrease and of CD3, CD4/CD8, and magnificent elevation of soluble interleukin-2 receptor(SIL-2R) in sera of recurrent herpetic keratitis cases when compared with the contrasts, we hold that the lower immune function in recurrent herpetic keratitis cases may attribute to the high level of soluble interleukin-2 receptor (SIL-2R) in the serum. The discovery can provide foundation for immunotherapy.

Adult↗
PubMed1998

Selection of EPS-deficient mutants (Exo-) from Rhizobiun huakuii 107 by region-directed Tn5 mutagenesis.

pJB-B5 was a recombinant plasmid of pRK415 containing the 5.9 kb B5 fragment from exoR'-11. After pJB-B5 was mutagenized by MT614 (mal::Tn5), 10 plasmids TN1-1, TN1-12, TN2-2, TN2-3, TN3-1, TN4-1, TN9-1, TN10-1, TN13-1, and TN14-1 with different Tn5 insertions in the B5 fragment were constructed. By conjugation of TN1-1, etc., into Rhizobium huakuii 107 containing the P-group plasmid pPH1JI which is incompatible with pRK415, and simultaneous selection for Rifr (conferred by strain 107), Gm(r) (conferred by pPH1JI), and Nmr (retention of Tn5), R. huakuii 107 transconjugant yields a strain in which Tn5 has recombined into the R. huakuii 107 genome. Three EPS-deficient (Exo-) mutants 107 (TN2-2), 107 (TN10-1), and 107 (TN13-1) were isolated and their inserted Tn5 was certified as the result of a double homologous recombinant event by Southern hybridization analysis. This result showed the Tn5 region-directed mutagenesis is an efficient way to select Exo- mutant in R. huakuii.

DNA Transposable Elements↗
PubMed1997

Overexpression of phospholipase C-gamma1 in rat 3Y1 fibroblast cells leads to malignant transformation.

Phospholipase C-gamma1 (PLC-gamma1) mediates signals from various extracellular origins to evoke cellular events such as mitogenesis. Previously, we reported that PLC-gamma1 was highly expressed in colorectal cancer and familial adenomatous polyposis, suggesting that PLC-gamma1 might be oncogenic. In this study, we have established rat 3Y1 fibroblasts that overexpress whole PLC-gamma1 and src homology 2 (SH2)-SH2-SH3 domain of PLC-gamma1. These cells showed a transformed phenotype and were tumorigenic when transplanted into nude mice. These results indicate that overexpression of PLC-gamma1 could transform rat fibroblasts, and the transformation is mediated by SH2-SH2-SH3 domain of PLC-gamma1.

Animals↗
PubMed1997

Cerebrospinal fluid apo E and apo A-I concentrations in early- and late-onset Alzheimer's disease.

We compared cerebrospinal fluid (CSF) apolipoprotein (apo) A-I and apo E concentrations in early- and late-onset Alzheimer's disease (EOAD (n = 11), LOAD (n = 15), respectively) with those in control subjects (n = 23). CSF apo A-I levels in both EOAD and LOAD were consistent with control subjects. However, CSF apo E levels were significantly lower in EOAD group (mean +/- SD; 2.65 +/- 1.69 mg/l, P < 0.05) and higher in LOAD group (5.90 +/- 1.94 mg/l, P < 0.01) than those in control group (4.16 +/- 1.69 mg/l). In addition, the epsilon4 allele frequency was not different between EOAD and LOAD groups. Although the reason for the difference in CSF apo E concentrations between two groups is unknown, CSF apo E concentration seems to be associated with the pathogenesis of EOAD and LOAD. The rate of apo E production and/or catabolism in the brain may be different between them.

Aged↗
PubMed1997

In vitro motility of AtKCBP, a calmodulin-binding kinesin protein of Arabidopsis.

AtKCBP is a calcium-dependent calmodulin-binding protein from Arabidopsis that contains a conserved kinesin microtubule motor domain. Calmodulin has been shown previously to bind to heavy chains of the unconventional myosins, where it is required for in vitro motility of brush border myosin I, but AtKCBP is the first kinesin-related heavy chain reported to be capable of binding specifically to calmodulin. Other kinesin proteins have been identified in Arabidopsis, but none of these binds to calmodulin, and none has been demonstrated to be a microtubule motor. We have tested bacterially expressed AtKCBP for the ability to bind microtubules to a glass surface and induce gliding of microtubules across the glass surface. We find that AtKCBP is a microtubule motor protein that moves on microtubules toward the minus ends, with the opposite polarity as kinesin. In the presence of calcium and calmodulin, AtKCBP no longer binds microtubules to the coverslip surface. This contrasts strikingly with the requirement of calmodulin for in vitro motility of brush border myosin I. Calmodulin could regulate AtKCBP binding to microtubules in the cell by inhibiting the binding of the motor to microtubules. The ability to bind to calmodulin provides an evolutionary link between the kinesin and myosin motor proteins, but our results indicate that the mechanisms of interaction and regulation of kinesin and myosin heavy chains by calmodulin are likely to differ significantly.

Amino Acid Sequence↗
PubMed1997

Marked increases in concentrations of apolipoprotein in the cerebrospinal fluid of poliovirus-infected macaques: relations between apolipoprotein concentrations and severity of brain injury.

Apolipoproteins in cerebrospinal fluid (CSF) might have important functional roles in the pathophysiology of brain and lipid metabolism in the vascular component. The present study examined apolipoprotein A-I (apo-A-I) and apolipoprotein E (apo-E) levels in CSF and serum from poliovirus-infected macaques. Poliovirus-infected macaques developed motor deficits and were classified into three groups: (1) muscle weakness in one or both legs; (2) partial paralysis in one or both legs; (3) complete paralysis in one or both legs. No motor deficits were evident in the control or sham-treated macaques. Apo-A-I concentrations in CSF were markedly elevated in poliovirus-infected macaques with weakness, partial or complete paralysis, in comparison with either control or sham-treated animals, and were proportional to the severity of motor impairment. Apo-E concentrations in CSF were also significantly elevated in poliovirus-infected macaques with complete paralysis. The magnitude of increase in CSF apo-A-I or apo-E concentrations was also closely associated with the degree of histologic neurological damage and inflammation (lesion scores). However, no changes in serum apo-A-I and apo-E concentrations were observed in the poliovirus-infected macaques compared with control macaques. Furthermore there were no significant correlations apo-A-I or apo-E concentrations between serum and CSF. We hypothesize that the elevation of apo-A-I and apo-E concentrations after poliovirus infection is caused by immune stimulation within the central nervous system (CNS). Measures of CSF apo-A-I and apo-E levels might serve as a useful marker for the severity and/or the range of CNS injury.

Animals↗
PubMed1997

Failure of insulin-like growth factor type I to suppress HIV type 1 in adult or umbilical cord mononuclear blood cells.

Insulin-like growth factor type I (IGF-I) has been used as a treatment for cachexia in adults with AIDS and has been reported to show inhibitory activity against HIV-1IIIB in cord blood mononuclear cells (CBMCs) in vitro at low-concentration (1%) fetal bovine serum (FCS). We evaluated the effect of IGF-I on MN, IIIB, and BaL strains, as well as on a patient isolate of HIV-1 in CBMCs and adult peripheral blood mononuclear cells (PBMCs). IGF-I failed to show any inhibitory effect on HIV replication in CBMCs or adult PBMCs under various culture conditions. In contrast to an earlier report of an antiviral effect, IGF-I augmented HIV-1 replication in PHA-stimulated PBMCs maintained in a low concentration of FCS.

Adult↗
PubMed1997

Evidence for K+ channels involvement in capillary sensing and for bidirectionality in capillary communication.

Although the capillary sensing and communication phenomenon has been characterized, its mechanism is not clear. It has been hypothesized that capillary sensing involves a membrane potential change in the capillary endothelium and/or pericyte and that communication represents an electrotonic spread of this change along the capillary. The goal of the present study was to address this hypothesis by examining the presence of K+ channels on the capillary and by determining bidirectionality of communication. Using intravital microscopy, we locally applied K+ (100 mM), acetylcholine (ACh; 3 mM), and norepinephrine (NE; 0.3 mM) on capillaries, 400-500 microns downstream from the arteriole, at the surface of the sartorius muscle in anesthetized frogs. Responses were measured in terms of red blood cell velocity (VRBC) changes in the stimulated capillary (control prestimulation VRBC ranged from 110 to 770 microns/sec). K+ and ACh caused significant 19 and 38% increases in VRBC, while NE caused a -46% decrease, respectively. The K+ response was blocked by local pretreatment with K+ channel blocker BaCl2 (1 microM) and by pretreatment with tetraethyl ammonium chloride (TEA; 5 mM). Responses to ACh and NE were attenuated by pretreatment with 1 microM BaCl2 (to 1%) and with 50 mM TEA (to -25%), respectively. In a separate experiment, NE (3 mM) application on the capillary 500 microns away from the draining venule (capillary occluded) caused a 19% venular constriction (i.e., similar to a reported 21% arteriolar constriction caused by the NE stimulus). We concluded that (i) K+ channels were present on the capillary and (ii) capillary communication was bidirectional. We interpreted these results to be consistent with the above hypothesis of membrane potential change and electrotonic spread.

Acetylcholine↗
PubMed1997

Impact of a function-based payment model on the financial performance of acute inpatient medical rehabilitation providers: a simulation analysis.

OBJECTIVES: To operationalize research findings about a medical rehabilitation classification and payment model by building a prototype of a prospective payment system, and to determine whether this prototype model promotes payment equity. This latter objective is accomplished by identifying whether any facility or payment model characteristics are systematically associated with financial performance. DESIGN: This study was conducted in two phases. In Phase 1 the components of a diagnosis-related group (DRG)-like payment system, including a base rate, function-related group (FRG) weights, and adjusters, were identified and estimated using hospital cost functions. Phase 2 consisted of a simulation analysis in which each facility's financial performance was modeled, based on its 1990-1991 case mix. A multivariate regression equation was conducted to assess the extent to which characteristics of 42 rehabilitation facilities contribute toward determining financial performance under the present Medicare payment system as well as under the hypothetical model developed. PARTICIPANTS: Phase 1 (model development) included 61 rehabilitation hospitals. Approximately 59% were rehabilitation units within a general hospital and 48% were teaching facilities. The number of rehabilitation beds averaged 52. Phase 2 of the stimulation analysis included 42 rehabilitation facilities, subscribers to UDS in 1990-1991. Of these, 69% were rehabilitation units and 52% were teaching facilities. The number of rehabilitation beds averaged 48. MAIN OUTCOME MEASURE: Financial performance, as measured by the ratio of reimbursement to average costs. RESULTS: Case-mix index is the primary determinant of financial performance under the present Medicare payment system. None of the facility characteristics included in this analysis were associated with financial performance under the hypothetical FRG payment model. CONCLUSIONS: The most notable impact of an FRG-based payment model would be to create a stronger link between resource intensity and level of reimbursement, resulting in greater equity in the reimbursement of inpatient medical rehabilitation hospitals.

Health Services Research↗
PubMed1997

Expression of a putative vesicular acetylcholine transporter facilitates quantal transmitter packaging.

A putative vesicular acetylcholine transporter (VAChT) was overexpressed in developing Xenopus spinal neurons by injection of rat VAChT cDNA or synthetic mRNA into Xenopus embryos. This resulted in a marked increase in the amplitude and frequency of miniature excitatory postsynaptic currents at neuromuscular synapses, reflecting an over 10-fold increase in the vesicular packaging of acetylcholine (ACh). The effect appeared in developing neurons even before synaptogenesis and was blocked by L-vesamicol, a specific blocker of ACh uptake into synaptic vesicles. Mutational studies showed that two highly conserved aspartate residues within putative transmembrane domains 4 and 10 are essential for the transport activity. These results provide direct evidence for the physiological function of a putative VAChT and demonstrate that quantal size can be regulated by changes in vesicular transporter activity.

Acetylcholine↗
PubMed1997

Mutation and downregulation of the transforming growth factor beta type II receptor gene in primary squamous cell carcinomas of the head and neck.

In the present study, we analyzed 28 squamous cell carcinomas of the head and neck (SCCHN) for mutations in the coding region of TbetaR-II using 'Cold' SSCP and automatic DNA sequencing analyses. Twenty-one percent (6/28) of the SCCHN examined contained TbetaR-II mutations compared with patient-matched normal tissues. These alterations included five missense mutations (A:T-->G:C transitions in codons 250, 401, 448 and 488, and a G:C-->T:A transversion in codon 373), and a 38-bp deletion between nucleotides 1825 to 1862. In addition to these code-altering mutations, one case exhibited a silent mutation (A:T-->G:C transition in codon 451) and three cases contained one of two potential population polymorphisms (codons 354 and 389). In contrast to colon and gastric cancers exhibiting microsatellite instability (MI) or replication errors (RER+), no 'indirect' frameshift mutations were identified within a 10-bp polyadenine repeat present in the TbetaR-II coding sequence. All of the mutations in the present study occurred within the highly conserved serine/threonine kinase domain and represent the first report of such 'direct' TbetaR-II mutations in primary human tumors. In addition, we analyzed a subset of SCCHN and corresponding normal samples for TbetaR-II mRNA expression using semi-quantitative multiplex RT-PCR. Expression of TbetaR-II was decreased by 24% to 74% in 20 of 23 SCCHN (87%) compared with patient-matched normal tissues. Taken together, the results from this study suggest that alterations in the nucleic acid sequence and mRNA expression of TbetaR-II are prevalent events in the development of SCCHN, which may deregulate cell cycle control.

Carcinoma, Squamous Cell↗
PubMed1997

Age-related changes in antibody repertoire: contribution from T cells.

The immune system of aged mice produces antibodies that are characterized by low affinity, diminished protection against infections and autoreactivity. It has been shown that these antibodies may be encoded by different immunoglobulin V genes and that the mechanism of somatic hypermutation in the V genes is inefficient. Studies on scid mice reconstituted with B and T cells from donors of different ages suggested that both lymphocyte subsets may contribute to the age-related changes in antibody repertoire. With help provided by T cells from young mice, the response to a hapten, nitrophenyl(acetyl), became gradually dominated by B-cell clones that rearranged a particular germline VH gene (V186.2). However, help from the aged T cells resulted in a heterogeneous response of B cells expressing many different V segments. Analysis of discrete foci of primary antibody-forming cells suggested that the aged T-helper cells are unable to govern the normally-occurring competition between the B-cell clones that have different affinities for the hapten. It is proposed that a signaling disequilibrium from the aged T cells, which provide less efficient help in quantitative terms, supports the growth of low-affinity B cells. This process may be exacerbated due to the apparent hyperactivity of aged B cells to CD40-mediated mitogenic signal.

Aging↗
PubMed1997

[Evaluation of emergency surgery in gestational trophoblastic tumours].

We retrospectively analyzed 27 cases of gestational trophoblastic neoplasia treated by emergency surgery from 1985-1996 at PUMC hospital. Seventeen cases were diagnosed of choriocarcinoma and 10 were invasive mole. Sixteen out of 27 patients were subjected to hysterectomy because of uterine perforation or severe uterine bleeding; 4 cases received unilateral oophorectomy because of torsion of theca lutein cyst. Emergency open surgery and excision of the metastatic brain tumour were undertaken in 3 patients with elevated intracranial pressure caused by brain edema and haemorrhage; 2 patients showed lifethreatening haemorrhage from vaginal metastatic tumour and were managed by operative intervention. Partial jejunectomy was performed in 2 patients due to rupture of jejunal metastatic mass. Of these 27 cases, 17 hadn't been treated with chemical reagents and 6 cases had received one course of chemotherapy before surgical procedures. After multiple courses of combined chemotherapy postoperatively, 23 patients had achieved complete remission. It is concluded that surgical intervention plays an important role in patients with trophoblastic disease when emergency situations (e.g. life-threatening haemorrhages) occur; early diagnosis and prompt initiation of chemotherapy might have rendered surgery unnecessary.

Adult↗