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Biomedical subjects

J Luan

Publications and source records attributed to J Luan.

33 records · Page 2Linked to original sources
PubMed2001

[Transconjunctival approach to the fractures of the orbital floor and infraorbital rim].

OBJECTIVE: To study the surgical approach to the orbital floor and infraorbital rim. METHOD: 15 cases of fractures of the orbital floor and infraorbital rim were treated with the transconjunctival approach. RESULT: All fractures of the orbital floor and infraorbital rim were repositioned and fixed through transconjunctival approach. Except for 1 case with mild canthal malposition, no other complication was observed. CONCLUSION: The transconjunctival approach can provide adequate exposure of the infraorbital rim and orbital floor without scar formation in the face.

Adolescent↗
PubMed2000

The tumorigenic and angiogenic effects of MGSA/GRO proteins in melanoma.

Continuous expression of the MGSA/GROalpha, beta, or gamma chemokine bestows tumor-forming capacity to the immortalized murine melanocyte cell line, melan-a. The mechanism for this transformation is unclear, although both autocrine and paracrine processes are possible because melan-a cells as well as endothelial cells express a low level of the receptor for this ligand. To further define the role of MGSA/GRO proteins in melanocyte transformation, two types of experiments were designed to neutralize the biological effects of MGSA/GRO in the transfected melan-a clones: (1) the effect of neutralizing antiserum to MGSA/GRO proteins on melan-a tumor growth was assessed; (2) the tumor-forming capacity of melan-a clones expressing ELR motif-mutated forms of MGSA/GRO with compromised receptor affinity was compared to the tumor-forming capacity of clones expressing wild-type MGSA/GRO. These experiments revealed that SCID mice inoculated with MGSA/GROalpha- or gamma-expressing melan-a cells and subsequently treated with antiserum to the respective chemokine exhibited decreased tumor growth. This reduction in tumor growth was accompanied by declining angiogenic activity in MGSA/GROgamma-expressing tumors. Moreover, athymic nude mice injected with melan-a cells expressing ELR-mutant forms of MGSA/GROalpha exhibited markedly impaired tumor-forming capacity compared with those mice injected with melan-a clones expressing wild-type MGSA/GRO. These data suggest that continuous expression of MGSA/GRO proteins may facilitate tumor growth by stimulating the growth of microvessels into the tumor (paracrine) and by affecting melanocyte growth (autocrine).

Animals↗
PubMed2000

A common apolipoprotein B signal peptide polymorphism modifies the relation between plasma non-esterified fatty acids and triglyceride concentration in men.

Insulin and non-esterified fatty acids (NEFA) are important regulators of triglyceride metabolism. The relations between these compounds and the effect of a common 3 amino acid deletion in the apolipoprotein B (ApoB) signal peptide (SP) following an oral glucose challenge have been investigated. The frequency of the shorter SP-24 allele was 32% (95% C.I. 29.5-36.5) in 725 subjects undergoing an oral glucose tolerance test (OGTT). Fasting plasma triglyceride concentration was positively correlated with fasting plasma insulin concentration and negatively with the degree of plasma NEFA suppression following the glucose challenge. Linear regression analysis showed the relation between triglyceride concentration and NEFA suppression, but not the relation between triglyceride concentration and fasting insulin, to be altered by the SP polymorphism in men but not in women. The strength of the association was dependent on the number of SP-24 alleles, with SP-24 homozygotes showing the greatest dependence (men P=0.031, women P=0. 914). It was proposed that the complex regulation of very low density lipoprotein (VLDL) output by NEFA and by insulin may explain, at least in part, the conflicting reports concerning the presence of the ApoB SP polymorphism, fasting serum lipids and ischaemic heart disease (IHD).

Adult↗
PubMed2000

Retinoic acid synthesis and expression of cellular retinol-binding protein and cellular retinoic acid-binding protein type II are concurrent with decidualization of rat uterine stromal cells.

Decidualization of stromal cells at the site of embryo implantation in the rat uterus is accompanied by expression of cellular retinol-binding protein and cellular retinoic acid-binding protein [CRABP(II)], whose presence has been shown to correlate with gain of ability to synthesize retinoic acid in other cells. Here we examined whether decidual cells also acquired the ability to synthesize retinoic acid, which would have important implications for understanding the implantation process. Decidual cells were isolated from the uterus on day 8 of pregnancy and cultured. When provided with retinol, they indeed synthesized and released retinoic acid to the medium. To follow acquisition of this ability more closely, artificial induction of decidualization was exploited. Ovariectomized rats were placed on a hormonal regimen that allows decidualization to occur in vivo, with oil stimulation, or in vitro, if cells are isolated on day 5 of the regimen and then cultured. Decidualization in vivo reproduced the expression of cellular retinol-binding protein and CRABP(II) seen during pregnancy. Stromal cells isolated on regimen day 2 synthesized little retinoic acid and expressed little alkaline phosphatase, a marker of decidualization. Stromal cells isolated on regimen day 5 had elevated levels of alkaline phosphatase, increasing during the 3 days of culture examined. The ability of the stromal cells to synthesize retinoic acid showed the same pattern: a substantially elevated production from that previously observed, on day 2, with production increasing significantly over the next 2 culture days. Thus, expression of CRABP(II) was correlated with gain of ability to synthesize retinoic acid. Retinoid signaling may be an important part of the process of embryo implantation.

Alkaline Phosphatase↗
PubMed2000

The CART gene and human obesity: mutational analysis and population genetics.

The cocaine- and amphetamine-regulated transcript (CART) peptide is a recently characterized neuropeptide implicated in the control of appetite. We hypothesized that genetic variation in CART may contribute to human obesity. The entire coding region of CART was determined by nucleotide sequencing in 91 unrelated subjects with severe early-onset obesity. A novel amino acid change, Ser66Thr, was found in 2 probands and in 0 of 100 control subjects but did not cosegregate with obesity in family studies. Two common polymorphisms were found in the 3'-untranslated region (A1475G and deltaA1457). An effect of these polymorphisms on body composition and intermediate phenotypes related to obesity was examined in a large Caucasian population in the U.K. Neither polymorphism showed any significant relationship with obesity; however, men heterozygous for the A1475G variant had significantly lower waist-to-hip ratio (WHR), fasting plasma insulin, and fasting triglycerides. Regression analysis indicated that the effects on insulin and triglycerides were likely to be secondary to the effects on WHR. Thus, we have conducted the first systematic study of the CART gene in human obesity, and although no clear association with obesity was found, the data suggest that genetic variation in the CART locus might influence fat distribution and variables related to syndrome X.

3' Untranslated Regions↗
PubMed2000

[Clinical analysis of 40 patients who were re-operated after prosthetic augmentation mammaplasty].

OBJECTIVE: To summarize the reasons of complications after prosthetic augmentation mammaplasty and explore the optimal preventive measures and therapy. METHOD: The reasons for 40 patients who were re-operated on after prosthetic augmentation mammaplasty were analyzed in as many aspects as possible, such as the location of the incision, the type of the prosthesis, etc. Preventive measures and therapy of the complications were also summarized. RESULTS: Capsular contracture was the most common reason for reoperation. The second was prosthetic rupture and translocation. The main reasons resulting in complications included impertinent indications, poor quality of the prosthesis and an incompetent surgeon. CONCLUSIONS: The key to reduce the complications is proper selection of good prosthesis, strict indications, better comprehension of the knowledge about prosthetic augmentation mammaplasty and a qualified plastic and aesthetic surgeon for the operation. The inareolar incision is the best choice to remedy the complications.

Adult↗
PubMed2000

[Study on the pharmacologic effect of propolis].

Pharmacologic effects of propolis were investigated in this article. The results suggested that propolis has pharmacologic functions in many aspects. It is a new-type medicine derived from animal in pharmacology and food both. To small mouse, propolis showed the functions of anti-fatigue and endurance to lack of oxygen. To high-blood-lipid-model mouse, it prevented increase of blood-mucus and blood lipid(TC, TG, LDL-C) (P < 0.05-0.01), but there were insignificant changes to red-blood-cell proportion (HCT) and high-density lipoprotein chelesteral (HDC-C). To small immunosuppessive-model mouse, propolis could strengthen macrophagocyte phagocytosis in the abdominal-cavity (P < 0.05), and increase the thymus-index (P < 0.05), but there were insignificant changes to the spleen-index. The LD50 > 7500 mg/kg to small mouse.

Adjuvants, Immunologic↗
PubMed2000

[The clinical study of tongue flaps repairing after resecting pharyngeal neoplasm and laryngeal neoplasm].

OBJECTIVE: To study the repair methods of the defect after resecting pharyngeal neoplasm and laryngeal neoplasm. METHODS: Four kinds of tongue flap, such as 1/3 tongue flap, 1/2 tongue base flap, tongue base flap and transverse tongue flap were devised and applied in 15 patients with pharyngeal neoplasm and laryngeal neoplasm. RESULTS: These tongue flaps were alive in all patients. The wound of 13 patients healed in I stage. Two patients dehiscenced because of infection and healed after treatment. All the patients deglutited well. One-year, 3-year, disease-free survive rate were 92.9% (13/14), 72.7% (8/11) respectively. CONCLUSION: Tongue flaps are obtained easily, with enough blood flow, adapted to pharyngeal environment, easily alive and low complication in repairing the pharyngeal defect. We think that these tongue flaps should be applied in clinic.

Adult↗
PubMed1999

[Culture of chondrocytes using allogenous acellular cartilaginous matrix].

OBJECTIVE: To observe the effect of chondrocyte culture with natural ECM made from allogenous acellular cartilage. METHODS: The allogenous acellular cartilaginous matrix was used as a scaffold in chondrocyte culture in vitro, comparing with the acellular perichondrium. The growth and regeneration of the chondrocytes in vitro were observed. RESULTS: The chondrocytes seeded on the acellular cartilaginous matrix grew well while the chondrocytes on the acellular perichondrium matrix grew poorly. CONCLUSION: The surface condition of the scaffold has a notable influence on the growth of the cells. The allogenous acellular cartilaginous matrix may provide a suitable condition for chondrocytes, and it has the possibility to be developed as a natural scaffold for tissue engineering.

Animals↗
PubMed1998

Proteolytic cleavage and activation of pro-macrophage-stimulating protein and upregulation of its receptor in tissue injury.

Macrophage stimulating protein (MSP) exists in blood as inactive pro-MSP. Cleavage yields active MSP, the ligand for a membrane receptor (RON) that is expressed on keratinocytes as well as macrophages. Because both cells have roles in tissue injury, we looked for active MSP and expressed RON in wounds. Concentration of pro-MSP + MSP in wound exudates was in the range for optimal activity. Western blot showed that MSP comprised about half the total, in contrast to less than 10% of the total in blood plasma. The presence of MSP was attributed to an exudate pro-MSP convertase that had an inhibitor profile consistent with a trypsin-like serine protease. Exudate evoked morphologic changes in macrophages in vitro like that of MSP. Removal of this activity by an anti-MSP column shows that exudate stimulation of macrophages is due to MSP. RON was infrequently detected in normal skin. RON protein was markedly upregulated in burn wound epidermis and accessory structures, in proliferating cells or differentiated cells, or both. RON was also detected on macrophages and capillaries. Tissue injury leads to cleavage of pro-MSP to MSP, which has potential to act on keratinocytes, macrophages, and capillaries, all components of the wound healing response.

Animals↗
PubMed1997

Mechanism and biological significance of constitutive expression of MGSA/GRO chemokines in malignant melanoma tumor progression.

By reverse transcriptase-polymerase chain reaction, enzyme-linked immunosorbent assay, and immunohistochemistry, MGSA-alpha, -beta, -gamma, and CXCR2 mRNA expression and proteins are detected in 7 out of 10 human melanoma lesions. The biological consequence of constitutive expression of the MGSA/GRO chemokine in immortalized melanocytes was tested in SCID and nude mouse models. Continuous expression of MGSA/GRO-alpha, -beta, or -gamma in immortalized melan-a mouse melanocytes results in nearly 100% tumor formation for each of the clones tested, whereas clones expressing only the neomycin resistance vector form tumors <10% of the time. Moreover, antibodies to the MGSA/GRO proteins slow or inhibit the formation of tumors in the SCID mouse model and block the angiogenic response to conditioned medium from the tumor-producing clones. Transcription of the MGSA/GRO chemokines is regulated by an enhancesome-like complex comprised of the nuclear factor-kappaB (NF-kappaB), HMG(I)Y, IUR, and Sp1 elements. In Hs294T melanoma cells the half life of the IKB protein is shortened in comparison to normal retinal epithelial cells, facilitating the endogenous nuclear localization of NF-kappaB. We propose that this endogenous nuclear NF-kappaB, working in concert with the 115-kDa IUR-binding factor, promotes constitutive expression of MGSA/GRO genes.

Animals↗
PubMed1996

[Eyebrow reconstruction by a scalp island flap based on the frontal branch of the superficial temporal artery].

The author studied the course and measured the length of the frontal branch of the superficial temporal artery in 30 normal subjects. 19 eyebrows were reconstructed in 11 burned patients using the scalp island flap based on the frontal branch of the superficial temporal artery. The results were satisfactory. The reconstructed eyebrows looked natural with wooly hair of the frontal hairline. This method can be used not only in male patients but also in female or pediatric patients.

Adult↗
PubMed1995

[Reduction mammaplasty using glandular pedicle].

A new technique for reduction mammaplasty with a glandular pedicle was designed based on the anatomical study of the vascular supply to the breast. The features of the procedure include using a pyramidal glandular pedicle that is reliably vascularized and definitely placed, maintaining a thin layer of parenchyme attached to the flap and the modified invert "T" closure. Clinical applications provided aesthetic and safe results of reliable nipple-areola survival, simplicity in breast mound creature and preservation of nipple sensitivity and the possibility of nursing function as well as less complications.

Adult↗