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Biomedical subjects

S Xia

Publications and source records attributed to S Xia.

At least 55 records · Page 3Linked to original sources
PubMed1997

[Reform of the pedicled abdominal subcorium vascular-net flap and its clinical application].

In order to resolve the shortcomings of traditional pedicled abdominal skin flap, the pedicled abdominal subcorium vascular-net flap was reformed and applied clinically. Twenty-eight cases with scar on hand or wrist were treated, including 20 males and 8 females. The age was ranged from 18 to 35 years old. The key point in the design was rotating 45 degrees of the flap from the primary site toward the pedicle. The ratio of the length to width of the flap was 1-1.8 : 1, and the wound of the donor site was covered by direct suture. Five to seven days later, all the flaps were divided and survived. The advantages of this flap were as follows: skin-grafting on the donor site was not necessary; the time needed for cutting the pedicle was shortened, and the flap is thinner than the traditional flap.

Adolescent↗
PubMed1996

Two hypothetical proteins of human aortic adventitia, with Ig kappa, collagenous, and aromatic-rich motifs.

Two of five clones, selected from an expression library of aortic adventitia, encode unique hypothetical proteins sharing sequences of Ig kappa, gly/pro rich (collagenous) motifs, and aromatic motifs that occur in several proteins of the extracellular matrix. Both proteins have a similar domain structure with at least 8 regions: (1) Ig kappa (84-120 residues in length); (2) ser/thr-rich motif (44-63); (3) a second Ig kappa motif (9-12); (4) either a possible calcium-binding motif or a gly/pro rich sequence (35-43); (5) an aromatic rich sequence (6-7); (6) another gly/pro rich sequence (62-72); (7) a third Ig kappa sequence (26-28); and (8) a C-terminal 68-70 residue sequence with another aromatic motif.

Amino Acid Sequence↗
PubMed1996

Partial amino acid sequence of a novel 40-kDa human aortic protein, with vitronectin-like, fibrinogen-like, and calcium binding domains: aortic aneurysm-associated protein-40 (AAAP-40) [human MAGP-3, proposed].

A microfibrillar protein (40 kDa) purified from the adventitia of the human abdominal aorta is immunoreactive with IgG harvested from the wall of abdominal aortic aneurysms. We have partially sequenced this protein and found that it has fibrinogen alpha-, beta-, and gamma-like domains, a vitronectin-like domain, and a possible site for binding calcium. Because of homologies with other microfibril-associated glycoproteins and because it is the third member of the family to be characterized in man, we suggest the name MAGP-3.

Amino Acid Sequence↗
PubMed1996

Features of autoimmunity in the abdominal aortic aneurysm.

PURPOSE: Previous work has revealed that nonspecific abdominal aortic aneurysms (AAAs) have a prominent infiltration of inflammatory cells and that soluble extracts of AAA tissue are rich in immunoglobulins. These observations raise the question whether autoimmune mechanisms play a role in the pathogenesis or progression of AAA disease. The hypothesis of this investigation was that IgG purified from aneurysmal specimens would be immunoreactive with normal components of the aortic wall (by means of immunohistochemistry) and with soluble proteins extracted from normal aortic tissue (by Western immunoblotting methods). METHODS: Immunoglobulin G extracted from AAA homogenates was used to detect immunohistochemical reactivity to connective tissue components in fixed sections of normal aorta obtained from an organ donor. Immunoblotting techniques were used to compare the reactivity of IgG (detected with secondary goat antihuman antibody) from 14 patients with AAA with soluble proteins extracted from normal and aneurysmal aortas. Immunoglobulins G purified from extracts obtained from nine patients with no AAA were used for control experiments. RESULTS: A unique band at approximately 80 kd was visualized when the filters were probed with IgG from 11 (79%) of 14 patients with AAA compared with only one (11%) of nine control subjects (P = .002 by Fisher's exact test). Immunoglobulins G from patients with AAA codistributed with matrix fibers in normal aortic sections, particularly in the adventitia (suggestive of a microfibrillar component). CONCLUSION: Our findings suggest that there are autoimmune features of AAA disease that might not only be informative in terms of AAA origin but also lead to more precise forms of pharmacologic down-regulation of disease progression.

Aortic Aneurysm, Abdominal↗
PubMed1996

A novel hypothesis to explain the hemorrhagic and connective tissue manifestations of Ebola virus infection.

The hemorrhagic and connective tissue complications of infection with Ebola virus are poorly understood. While searching for homologies and motifs of the aortic aneurysm-associated autoantigenic protein 40 kDa (AAAP-40), we have noted some short sequences (possibly shared epitopes) that occur in the envelope glycoprotein (40 kDa) of the Ebola virus. As a first step toward determining whether molecular mimicry of human matrix proteins by the Ebola virus protein might explain some of the severe connective tissue manifestations of infection, we have tested whether immunoglobulin (IgG) purified from the sera of patients with abdominal aortic aneurysm (AAA) are immunoreactive with the 40-kDa protein of the Ebola virus. Immunoblots of soluble Ebola proteins (strain Mayinga/Zaire) were probed with IgG's purified from the sera of eight patients with AAA and two healthy young control volunteers. The proteins were also probed with IgG extracted from the walls of two surgical aneurysm specimens. Serum IgG from eight consecutively studied AAA patients was immunoreactive with an Ebola virus protein of 40 kDa, consistent with the envelope glycoprotein. IgG's extracted from the walls of two AAAs were also reactive. The control sera were not reactive. In addition to the Ebola sequences in AAAP-40, an Ebola sequence also occurs in the microfibril-associated glycoprotein-4 (MAGP-4), which is distributed ubiquitously throughout connective tissue with elastin. We hypothesize that the catastrophic hemorrhagic and connective tissue complications of Ebola virus infection may be the result of these shared epitopes.

Aged↗
PubMed1996

Anatomy of vasculature of 850 spleen specimens and its application in partial splenectomy.

BACKGROUND: Anatomic knowledge of vasculature of the splenic lobe and segment is of great clinical significance in partial resections and transplantation of the spleen. METHODS: The methods of two-colored corrosion casting, roentgenography, and anatomic dissection were used to evaluate the vasculature of the splenic hilum and intraspleen. On this basis splenic lobectomy and segmentectomy were performed on 42 patients with traumatized spleens. RESULTS: In the observation of 850 spleen specimens the spleen showed a single lobar artery in 7 cases (0.8%), two lobar arteries in 730 cases (86%), three lobar arteries in 104 cases (12.2%), and multiple lobar arteries (i.e., more than three lobar arteries) in 9 cases (1%). In a subgroup of 276 specimens 17%, 53%, 24%, 4%, 1%, and 1% of spleen specimens had three, four, five, six, seven, and eight segmental arteries, respectively. The result from a subgroup of 280 specimens indicated that mean percentages of the existence of the superior and inferior polar arteries and of the coexistence of both polar arteries were 31.3%, 38.8%, and 13.3%, respectively. Relative avascular planes between segments or lobes were seen. Basic steps of splenic lobectomy or segmentectomy include mobilization of the injured spleen, ligation of vessels in the lobe or segment, transection of the splenic parenchyma, and sutures of the cut surface of the remaining spleen. The postoperative courses of all 42 patients undergoing partial splenectomy were uneventful. No postoperative bleeding and necrosis of the remaining spleen or infectious complications were registered. CONCLUSIONS: Anatomically the spleen is defined with two primary lobes (the superior lobe and inferior lobe), one accessory lobe, and three to five segments. This new classification facilitates surgeons to perform partial resections of the spleen and allotransplantation of the hemispleen from a living related donor in human beings.

Adolescent↗
PubMed1996

[The injury of liver sinusoidal endothelial cells in a rat's isolated liver perfusion (ILP) model for regional chemotherapy].

To observe the pathological changes of liver sinusoidal endothelial cells, the regional perfusion with different dosage of 5-FU was performed by using modified rat's model of ILP. The results demonstrated that ILP with over maximum tolerence dosage of (MTD) 5-FU resulted in irreversible damage of liver and endothelial cells. The endothelial cells were more fragile than liver cells. The changes of TXA2 and PGI2 balance play an important role in the process of damage of endothelial cells.

6-Ketoprostaglandin F1 alpha↗
PubMed1996

Changes of plasma endothelin concentrations before and after percutaneous balloon mitral valvuloplasty in patients with mitral stenosis.

Plasma concentrations of endothelin in blood from the femoral vein and the antecubital vein were measured in 35 patients with mitral stenosis and heart failure before and after percutaneous balloon mitral valvuloplasty (PBMV). The basal plasma concentrations of endothelin in blood from the antecubital vein in the patients were significantly higher than those in 32 control subjects (15.40 +/- 3.32 vs. 9.59 +/- 2.66 pg/ml, P < 0.001). Plasma endothelin concentrations in patients in New York Heart Association functional classes II and III were significantly higher than those in control subjects, respectively. The concentrations of endothelin in patients with atrial fibrillation were also significantly higher than those in patients with normal sinus rhythm. Ten to fifteen minutes after PBMV, plasma endothelin concentrations in blood from the femoral vein significantly decreased from 16.14 +/- 3.34 to 13.74 +/- 3.78 pg/ml (P < 0.01). Seventy-two hours after the procedure, the concentrations of endothelin in blood from the antecubital vein had fallen to 12.31 +/- 2.55 pg/ml (P < 0.001 vs. before PBMV and control subjects). Plasma endothelin concentrations still tended to be higher in patients with atrial fibrillation than those in normal sinus rhythm, but the difference did not reach statistical significance. There were weak but significantly correlations of plasma endothelin concentrations with the mean left atrial pressure (r = 0.424, P < 0.001), mean right atrial pressure (r = 0.323, P < 0.01), mean transmitral pressure gradient (r = 0.397, P < 0.001), heart rate (r = 0.350, P < 0.005) and mitral valve area (r = -0.454, P < 0.001) in the patients before and after PBMV.

Adolescent↗
PubMed1996

[Expression of CDKN2 gene product in human bronchogenic carcinoma].

OBJECTIVE: To examine the expression of P16 protein in bronchogenic carcinoma and normal tissue adjacent to carcinoma and to determine the relationship between the gene and bronchogenic carcinoma. METHOD: Using a rabbit polyclonal antibody against P16 (N-20), the expression of P16 protein was studied immunohistochemically on formalin fixed, paraffin embedded sections. RESULTS: The cytoplasmic P16 protein was mainly present in normal bronchial epithelium (93.8%), serous gland (92.6%) and alveolar epithelium (71.4%), the expression levels of P16 were significantly lower in carcinoma tissues (61.9%) when compared to levels in their normal counterparts (P < 0.01). Among tumors, squamous cell carcinomas and small cell carcinomas exhibited lower P16 expression levels compared with adenocarcinomas (P < 0.01). The expression levels of P16 were lower in poorly-differentiated adenocarcinomas compared with those in well-differentiated adenocarcinomas (P < 0.05). CONCLUSIONS: The results suggested that CDKN2 gene was a tumor suppressor gene, the inactivation of which were involved in the carcinogenesis of bronchogenic carcinoma and implicated in tumor differentiation.

Adenocarcinoma↗
PubMed1995

Allotransplantation of whole spleen in patients with hepatic malignant tumors or hemophilia A. Operative technique and preliminary results.

BACKGROUND: It has been reported that the spleen performs a vital function in the fight against malignant tumors. The spleen is the primary producer of tuftsin, which can directly or indirectly kill tumor cells or inhibit their growth. The spleen is also believed to produce coagulating factor VIII. Therefore, allotransplantation of the spleen can be used in the treatment of patients with malignant tumors and hemophilia A. DESIGN: Heterotopic allotransplantation of whole spleen was performed in six patients with advanced hepatocellular carcinoma and hemophilia A. An adjuvant immunotherapy with interferon alfa was simultaneously administered in the patients with liver cancer. SETTING: Tongji Hospital, Tongji Medical University, Wuhan, China. RESULTS: Among six cases of allografting of whole spleen, five grafts were successful; one failed because of torsion of the splenic hilum. Three patients with hepatocellular carcinoma survived 9, 11, and 5 months after transplantation. Marked shrinkage of hepatic tumors and reduced serum alpha-fetoprotein levels were observed in these patients. On 5-year follow-up, three patients with hemophilia who had undergone splenic allografts were alive, and two had experienced substantial clinical improvement. In these two patients, when the grafts were functioning well and the recipients were free of acute rejection or graft-vs-host reaction, the mean plasma factor VIII activity remained between 30% and 36%, with peak factor VIII activities of 53.7% and 66.6%. We also evaluate operative technique and posttransplantation complications. CONCLUSION: Our results strongly imply that the spleen is one of the primary sites of synthesis of factor VIII and that the spleen has an inherent ability to fight malignant diseases. Allografting of whole spleen may be a promising technique for the treatment of patients with unresectable hepatocellular carcinoma and severe hemophilia A.

Adult↗
PubMed1995

Zonal biochemical and morphological characteristics in BPH.

OBJECTIVE: To compare androgen, oestrogen, progesterone and epidermal growth factor receptor concentrations in the transition zone and peripheral zone of the prostate in benign prostatic hyperplasia (BPH), and to relate these findings to epithelial and stromal composition. PATIENTS AND METHODS: Tissue from both the transition and peripheral zone of the prostate was obtained from 26 patients undergoing transurethral prostatectomy for benign prostatic obstruction and used for both receptor binding studies and morphometric analysis. Androgen receptor (AR), oestrogen receptor (ER), progesterone receptor (PR) and epidermal growth factor receptor (EGFR) concentrations were assayed by saturation binding with a competitive inhibitor. The epithelial, stromal and luminal composition of the tissue was determined using a Zeiss AxioHOME microscope workstation. RESULTS: The epithelial content was significantly greater in the transition zone than in the peripheral zone. No overall zonal difference in AR concentration was detected; however, when values were expressed relative to the epithelial component, the AR content was significantly higher in the peripheral zone. Conversely, overall EGFR concentrations were significantly greater in the transition zone, although not when expressed per unit epithelium. Higher concentrations of oestrogen receptor were measured in the transition zone per unit stroma. No zonal difference in PR was detected. However, there was a significant correlation between AR and PR in the peripheral zone and between EGFR and AR in the transition zone. CONCLUSION: These data demonstrate that receptor concentrations should be related to tissue composition. Concentrations of AR were higher in the peripheral zone epithelium than in transition zone epithelium, suggesting greater androgen dependence. This may be important in determining its greater propensity for malignancy. Although EGFR concentrations were greater in the transition zone, there was no zonal difference after correction for the amount of epithelium. Finally, higher concentrations of ER were detected in the transition zone stroma which may reflect important zonal differences in regulating growth and provides further evidence of a role for oestrogens in BPH.

ErbB Receptors↗
PubMed1995

Methods of training and constructing multilayer perceptrons with arbitrary pattern sets.

This paper presents two compensation methods for multilayer perceptrons (MLPs) which are very difficult to train by traditional Back Propagation (BP) methods. For MLPs trapped in local minima, compensating methods can correct the wrong outputs one by one using constructing techniques until all outputs are right, so that the MLPs can skip from the local minima to the global minima. A hidden neuron is added as compensation for a binary input three-layer perceptron trapped in a local minimum; and one or two hidden neurons are added as compensation for a real input three-layer perception. For a perceptron of more than three layers, the second hidden layer from behind will be temporarily treated as the input layer during compensation, hence the above methods can also be used. Examples are given.

Algorithms↗
PubMed1995

Changes of plasma beta-endorphin levels before and after percutaneous transvenous mitral commissurotomy in patients with mitral stenosis.

To clarify the contribution of left atrial pressure to the secretion of beta-endorphin, we have investigated the relation between plasma beta-endorphin levels and hemodynamic changes in 35 patients with mitral stenosis undergoing percutaneous transvenous mitral commissurotomy (PTMC). Before PTMC, plasma beta-endorphin levels obtained from the antecubital vein (28.91 +/- 5.59 pg/ml) and from the femoral vein (28.20 +/- 5.44 pg/ml) in the patients with mitral stenosis were significantly higher than those obtained from the antecubital vein in the healthy volunteers (22.59 +/- 3.86 pg/ml, n = 34, P < 0.001 for each). The levels of beta-endorphin in the femoral vein correlated well with the mean left atrial pressure (r = 0.777, P < 0.001) and the mean right atrial pressure (r = 0.450, P < 0.01) before the procedure. The antecubital venous levels of beta-endorphin in patients in New York Heart Association functional Classes II (26.45 +/- 5.39 pg/ml, n = 20) and III (32.20 +/- 4.02 pg/ml, n = 15) were significantly higher than those in control subjects (P < 0.005 and P < 0.001, respectively). The differences between Classes II and III were significant (P < 0.001). The plasma levels of beta-endorphin in the patients complicated with atrial fibrillation were also significantly higher than those in patients with normal sinus rhythm (33.31 +/- 3.22 pg/ml, n = 13 vs 26.32 +/- 5.07 pg/ml, n = 22, P < 0.001). In ten to fifteen minutes after commissurotomy, plasma levels of beta-endorphin in the femoral vein significantly increased from 28.20 +/- 5.44 to 33.14 +/- 5.72 pg/ml (P < 0.001). In seventy-two hours after the procedure, plasma beta-endorphin levels in the antecubital vein fell to 24.37 +/- 2.59 pg/ml (P < 0.001 vs before PTMC and P < 0.05 vs control subjects). Plasma beta-endorphin levels in the patients with atrial fibrillation (26.62 +/- 2.36 pg/ml, P < 0.001 vs before PTMC and P < 0.002 vs control subjects) were still higher (P < 0.001) than those in patients with normal sinus rhythm (23.05 +/- 1.65 pg/ml, P < 0.001 vs before PTMC and P > 0.50 vs control subjects. There was a significant correlation between the levels of beta-endorphin in the antecubital vein and heart rate (r = 0.502, P < 0.001), mean transmitral pressure gradient (r = 0.543, P < 0.001) or mitral valve area (r = -0.710, P < 0.001) before and 72 hours after the procedure.

Adolescent↗
PubMed1995

[The mechanism for splenic promoting effects on liver cirrhosis].

The model of liver cirrhosis was induced by CCl4 and alcohol in rats, which were subjected to splenectomy or given Tuftsin. The isolated and purified liver parenchymal, Kupffer and Ito cells were cultured with CCl4 and splenic conditional fluid or Tuftsin. The RNA isolated from the liver tissues of cirrhosis animals were hybridized with five kinds of cDNA probes. In this study we explored the mechanism of spleen's promoting effects on the liver cirrhosis formation at the whole body, cellular and molecular levels. The result showed that in cirrhosis model, the levels of IL1, IL6 and TNF alpha in serum of rats in imitative splenectomy or Tuftsin group were significantly increased compared to those in splenectomy group (P < 0.05). Cell culture showed that if medium contained CCl4 and splenic conditional fluid or Tuftsin, its cells can secrete more fibronectin, laminin and collagen I than those cultured in medium only contained CCl4 (P < 0.05). Slot blot hybridization showed that the RNA isolated from liver of rats in imitative splenectomy or Tuftsin group hybridized with probes of TNF alpha, IL1 beta, TGF beta and Collagen I had a more high density picture of X-ray than that isolated from liver of rats in the splenectomy group. Should be it a complex process for spleen to promote liver cirrhosis formation, in which the TGF beta gene expression enhancement may be the key of splenic effects on liver fibrosis.

Animals↗
PubMed1995

[Immunohistochemical analysis of nm23 gene product/nucleoside-diphosphate kinase expression in human lung carcinoma].

It was proposed that nm23 gene may function as a suppressor gene for tumor metastasis. Using an antibody to NDPK, levels of NDPK/nm23 expression in lung carcinomas were examined immunohistochemically, 45 of 58 squamous carcinomas and 26 of 36 adenocarcinomas showed strong immunoreactivity for NDPK/nm23 in most of cancer cells within tumor tissues. On some normal bronchial epithelium and serous glands, there also show weak expression. No relationship was found between NDPK/nm23 expression and clinicopathological parameters including tumor grade, size, nodal involvement and stage but the increases in NDPK/nm23 expression were stronger in advanced stages of squamous cell carcinomas. In conclusion, our results indicate that the increased NDPK/nm23 expression in the analysed carcinomas is not consistent with the proposed metastasis-suppressor function, but the nm23 gene may be implicated in the mechanism of carcinogenic process and tumor progression.

Adenocarcinoma↗