Biomedical subjects

L Wang

Publications and source records attributed to L Wang.

At least 1,099 records · Page 61Linked to original sources

PubMed1999

Bone marrow-derived dendritic cells incorporate and process hydrophobized polysaccharide/oncoprotein complex as antigen presenting cells.

We have previously shown that a novel hydrophobized polysaccharide/oncoprotein complex vaccine can induce immune responses against the HER2/neu/c-erbB2 (HER2) expressing tumors. Bone marrow-derived dendritic cells (DCs), as antigen presenting cells (APCs), are the first candidates for presentation of tumor antigens. The aim of this study was to see whether DCs are able to elicit antigen specific host immune responses by stimulating the proliferation of T cells after exposure to cholesteryl group bearing pullulan (CHP) and HER2 protein complex. Vaccination by CHP-HER2 complex was as effective as cholesteryl group bearing mannan (CHM) and HER2 complex on which we reported previously. Immunization of mice with HER2 expressing CMS17HE tumor cells generated both CD4+ T cells and CD8+ T cells reactive with CHP-HER2 complex pretreated DCs. In addition, immunization with either CHP-HER2 complex or HER2 protein alone could also generate both CD4+ T cells and CD8+ T cells specifically reactive with CHP-HER2 complex pretreated DCs. The complete rejection of tumors occurred when immunization with CHP-HER2 complex pretreated DCs was started 10 days after tumor inoculation. Therefore, bone marrow-derived DCs pretreated with hydrophobized polysaccharide/oncoprotein complex are a powerful tool for enhancing the effectiveness of oncoprotein for anti-tumor vaccination, opening new options for immune cell therapy.

Animals↗

PubMed1999

Rickettsia serosurvey in Kimberley, Western Australia.

To determine if antibodies to rickettsiae (scrub typhus, spotted fever, and typhus group rickettsiae) occur among persons living in the Kimberley (northern tropical) region of Western Australia, 920 sera collected in a non-random manner in 1996 from patients in Kununurra, Broome, Fitzroy Crossing, Wyndham, Derby, and Halls Creek were tested by micro-immunofluorescence for antibodies to a panel of rickettsial antigens. Of 920 sera examined, 52 (5.6%) were positive for antibodies to one or more of the three groups of rickettsial microorganisms. The largest group of sera (24; 2.6%) were positive for scrub typhus (Orientia tsutsugamushi). Eleven other sera (1.2%) were positive for scrub typhus and spotted fever group rickettsiae and four (0.4%) were positive for scrub typhus, spotted fever group, and typhus group rickettsiae. In addition 13 sera (1.4%) were positive only for spotted fever group rickettsiae. In this study, only titers > or = 1:256 were considered significant. Thus, there is serologic evidence for scrub typhus and spotted fever group rickettsial infections in the Kimberley region of Western Australia. Because of the method of serum collection, it is not possible to determine the prevalence of seropositivity, but the data support the need for a proper epidemiologic study of rickettsial diseases in this region of Australia.

Antibodies, Bacterial↗

PubMed1999

Serodiagnosis of Hansen's disease/leprosy by enzyme-linked immunosorbent assay using cord factor (trehalose 6,6'-dimycolate) as an antigen.

IgG and/or IgM antibodies against mycobacterial cord factor (trehalose 6,6'-dimycolate, TDM) in sera of 65 patients of Hansen's disease (21 cases with smear-positive and 44 cases with smear-negative) and 60 healthy individuals were tested by enzyme-linked immunosorbent assay (ELISA) with TDM purified from Mycobacterium tuberculosis H37Rv as an antigen. Of 65 patients with Hansen's disease, 58 cases (89.2%) had positive results (21 samples from 21 patients, 100% with acid-fast bacilli positive in the lesion, and 37 samples from 44 patients, 84.0% with acid-fast bacilli negative Hansen's disease diagnosed clinically). The sensitivity and specificity of anti-cord factor ELISA were higher than those of anti-phenolic glycolipid-I (PGL-I) agglutination test. Among the total, 34 patients were classified clinically into three types of the disease, lepromatous leprosy (LL), borderline lepromatous (BL) and borderline tuberculoid (BT). The antibody titer showed LL > BL > BT, indicating that the elevation of anti-cord factor antibody titers appeared to be parallel with the degree of humoral immune response against M. leprae. By using semisynthetic cord factor consisting of a single subclass of mycolic acid from M. tuberculosis, it was revealed that sera from patients with Hansen's disease were highly reactive against alpha-mycoloyl cord factor (alpha-TDM) and less reactive against methoxy mycoloyl TDM (methoxy TDM), differed from sera of tuberculosis patients, which were highly reactive against both methoxy and alpha-mycoloyl cord factor (alpha-TDM). Most of sera from patients with Hansen's disease were more reactive against TMM than TDM, differed from sera of tuberculosis patients which were highly reactive against TDM. ELISA using TDM as an antigen is simple, reproducible and useful for the rapid serodiagnosis of Hansen's disease, especially for smear-negative cases.

Aged↗

PubMed1999

Glomus coccygeum in surgical pathology specimens: small troublemaker.

BACKGROUND: Rarely encountered nonpathologic structures may pose diagnostic problems and cause unnecessary special investigations. More importantly, however, they may be falsely accused as culprits in unrelated pathologic processes. Glomus coccygeum is one such structure. Glomus bodies (including coccygeal glomus) consist of modified smooth muscle cells arranged in layers around small vascular channels. When found in distal extremities, they generally do not represent a diagnostic problem; however, large glomus bodies present in a pericoccygeal location (glomus coccygeum) may cause significant problems for a surgical pathologist unfamiliar with this structure. DESIGN: We reviewed 37 coccygeal bones removed during rectal resection for carcinoma (rectal and uterine) and for various other reasons, among which was a single case of coccygodynia. Immunohistochemical and ultrastructural examinations were performed in selected cases. RESULTS: Sharply circumscribed glomus bodies composed of various proportions of glomus cells without atypia or pleomorphism and without expansile growth or infiltration of surrounding soft tissue or bone were identified in 50% of cases. Size varied significantly (maximum 4 mm), but paradoxically the smallest glomus body (less than 1 mm) was found in the case of coccygodynia. Glomus coccygeum posed a significant diagnostic challenge to the pathologists involved in these cases, as the retrospective review found that it was diagnosed correctly in only 3 cases. CONCLUSIONS: Glomus coccygeum is a nonpathologic structure that exhibits significant variation in size and proportion of the constitutive elements. Immunohistochemical demonstration of smooth muscle actin and neuron-specific enolase in glomus cells may be beneficial for accurate identification of this organelle.

Actins↗

PubMed1999

Intraepidermal nerves in human skin: PGP 9.5 immunohistochemistry with special reference to the nerve density in skin from different body regions.

The intraepidermal nerves of normal adult human skin were demonstrated by employing a powerful marker of neuronal elements, protein gene product (PGP) 9.5. There were two types of epidermal nerves, free nerve endings and nerves in the Merkel cell-neurite complex. The free nerve endings distributed to, and terminated in, all the strata basale, spinosum and granulosum, and they appeared as thin fibers, mostly varicose, branched or single processed, straight or bent. They existed at every site of the human body, including face, trunk and extremities. However, the densities of these nerves varied in different body parts and areas. The number of nerves decreased from the trunk to the distal parts of the limbs, and small denser 'innervation patches' showed up in the epidermis which were identified in confocal microscopy as one morphologic terminal field coming from the same dermal nerve bundle. This study has confirmed the existence of epidermal nerves in normal adult human skin, and presented a more clear picture than earlier. The difference between densities of epidermal nerves at different body areas implies area-specific functions of the intraepidermal nerve terminals. The observed intraepithelial nerve fibers may have a pain-perceiving role, however, also trophic or immunoregulatory roles can not be excluded.

Adult↗

PubMed1999

Incorporation of an (125)I-labeled hexa-iodinated diglyceride analog into low-density lipoprotein and high specific uptake by cells of cervical carcinoma cell lines.

The feasibility of using low-density lipoprotein (LDL) to deliver cytotoxic drugs to tumor cells has been explored since the 1980s, when cells of a number of cancer cell lines were found to have higher LDL receptor activity than normal cells. Such differential uptake between tumor and normal cells may provide a unique opportunity to use LDL as a tumor-specific carrier of radiopharmaceuticals for the clinical management of cancer. In this study, an (125)I-labeled hexa-iodinated diglyceride analog, 1, 3-dihydroxypropan-2-one 1,3-diiopanoate (DPIP), was synthesized and incorporated into LDL using a fusion technique. It was found that approximately 500 [(125)I] DPIP molecules were incorporated into each LDL particle. Cells of three human cervical tumor cell lines, HeLa, SiHa and C-33A, were used to examine the cellular uptake of the [(125)I]DPIP-LDL conjugate. It was shown that the [(125)I]DPIP-LDL conjugate was specifically bound to and taken up by cervical tumor cells through an LDL receptor-mediated endocytosis pathway. The results suggest that LDL may be a selective carrier for delivering hydrophobic radiopharmaceuticals to cancer cells and particularly for the diagnosis of cervical tumors.

Binding Sites↗

PubMed1999

Effects of MK-447 on platelet shape change, aggregation, and ATP release by collagen, ADP, and stable analogue of thromboxane A2 in rabbit platelets.

AIM: To investigate the effects of MK-447 on platelet shape change, aggregation, and ATP release by collagen (Col), ADP, and stable analogue of thromboxane A2 (STA2) in rabbits. METHODS: Platelet shape change and aggregation were quantified in light transmission by turbidimetric method and release reaction was assessed by the amount of ATP in platelet-rich plasma (PRP). RESULTS: (1) MK-447 100-700 mumol.L-1 caused only the shape change, which was not inhibited by indometacin 3 mumol.L-1. Platelet shape changes by Col, ADP, and STA2 were reduced (P < 0.01) after the addition of MK-447. The lag phase was prolonged (P < 0.01) in Col and shortened (P < 0.01) in ADP. (2) MK-447 reduced the aggregation by Col 5 mg.L-1 (P < 0.01), and enhanced that by ADP 0.3-10 mumol.L-1 and STA2 0.1-3 mumol.L-1 (P < 0.01). (3) The release reaction by STA2 1-3 mumol.L-1 was also increased (P < 0.01). The effects of MK-447 on STA2 were not inhibited by S-145. CONCLUSION: MK-447 induced the platelet shape change, and showed the dual effects, inhibition or enhancement, on the actions by different aggregating agents.

Adenosine Diphosphate↗

PubMed1999

[Investigation on the prevalence and influencing factors to anemia in women at reproductive age].

OBJECTIVE: To investigate the prevalence of anemia in women of reproductive age and to analyze the influencing factors in anemia. METHODS: A total number of 1,529 women aged 15-49 years old including workers, farmers, cadres and students were tested with Hb and FEP and investigated through questionnaire including related influencing factors. Statistical analysis was performed using SPSS/PC statistical software. RESULTS: Mean value of Hb was 116.35 g/L (SD 14.67 g/L) in 1,529 cases and the prevalence rate of anemia was 31.2%. Majority of the anemia identified belonged to the 'iron deficiency type'. Influencing factors on anemia included occupation, education, marriage status, menstruation, status of family expenses and physical exercise. CONCLUSION: The prevalence rate of anemia in reproductive aged women was high, thus more attention should be paid. In order to lower the incidence of anemia, preventive and intervenient measurements should be conducted accordingly.

Adolescent↗

PubMed1999

Fluoromicroscopic detection of myc-tagged GLUT4 on the cell surface. Co-localization of the translocated GLUT4 with rearranged actin by insulin treatment in CHO cells and L6 myotubes.

We earlier developed a novel method to detect translocation of glucose transporter type 4 (GLUT 4) directly, quantitatively and simply using c-MYC epitope-tagged GLUT4 (GLUT4myc) Kanai F, Nishioka Y, Hayashi H, Kamohara S, Todaka M, Ebina Y: J Biol Chem 268: 14523-14526, 1993). We further developed the method to visualize GLUT4myc on the cell surface++ by fluorescence microscope using a highly sensitive immunochemical detection system in tissue culture cells stably expressing GLUT4myc. The translocation of GLUT4myc was observed on stimulation with insulin in 3T3-L1 adipocytes, CHO cells and L6 myotubes stably expressing GLUT4myc. Platelet-derived growth factor (PDGF), norepinephrine and bradykinin also triggered GLUT4 translocation in CHO-GLUT4myc cells stably expressing each receptor. To observe the distribution of GLUT4 and actin after insulin treatment, double staining for GLUT4myc and actin was performed. Translocated GLUT4myc on the cell surface was co-localized with rearranged actin in CHO cells and L6 myotubes. This result suggests that a correlation exists between GLUT4 translocation and actin rearrangement.

3T3 Cells↗

PubMed1999

[Quality control of plasma(serum) specimen for the detection of HCV RNA with PCR].

OBJECTIVE: To define the optimal collection and storage parameters of serum (plasma) for HCV RNA detection. METHODS: The serum(plasma) obtained from HCV RNA positive patients by different means and different processing and storage conditions, then HCV RNA was detected with the fluorescent quantitative PCR. RESULTS: The centrifugation was performed within 2 hours after formation of the clot, loss of HCV RNA titers was 10.42% and significant loss of HCV RNA titers 40.49% was observed after 4 h. The HCV RNA titers in plasma samples with anticoagulants were much higher than that in serum samples(citrate sodium-anticoagulized 40.97%, EDTA-anticoagulated 53.14%). There was no loss of HCV RNA with up to three freeze-thaw cycles. A significant decrease in HCV RNA(15.6%) was observed at -20 degrees C after one year. CONCLUSIONS: The results suggested that it is important to process and store clinical samples for HCV RNA detection. The EDTA-K2 as anticoagulants the plasma must be collected within 3 h, and the serum must be prepared within 2 hours after hemosposia. It is essential to store the sample under -70 degrees C for the stability of HCV RNA in a longer time.

Blood Specimen Collection↗

PubMed1999

[Analysis on the treatment of 1,020 patients with immunologic infertility].

OBJECTIVE: To investigate the treatment for immunologic infertility. METHODS: Serum antisperm antibody, anti-ovarian antibody, anti-endometrial antibody and anti-hCG antibody in 1,020 female patients with primary or secondary infertility were tested. Patients were treated with dexamethasone, vitamin E and vitamin C for 3 cycles consecutively as one course. RESULTS: The detective rates of the above antibodies were 25.88%, 22.86%, 32.81% and 23.61% respectively. After one course of treatment, the disappearance rates of the antibodies mentioned were over 90%, and the average pregnancy rate was up to 30%. CONCLUSION: Corticosterocls may reduce or even eliminate the effects of the immune factors on infertility.

Adult↗

PubMed1999

[Study on tumor necrosis factor and pathogenesis of pregnancy induced hypertension].

OBJECTIVE: To study the role of tumor necrosis factor (TNF-alpha) in the pathogenesis of pregnancy induced hypertension (PIH). METHODS: Radioimmunoassay was used to measure the levels of TNF-alpha in 25 severe PIH patients and 25 normal pregnant women. Umbilical vein endothelial cells were cultured with TNF-alpha (500 U/ml) or without TNF-alpha. The concentration of endothelin-1 (ET-1), 6-ket-PGF1 alpha, nitrite (NO2-), expression of fibronectin(FN) and white blood cells adhesion to the surface of endothelial cells test were measured. RESULTS: The levels of TNF-alpha in serum of severe PIH patients were significantly higher than that of normal pregnant women (P < 0.05). In endothelium culture supernatant with TNF-alpha group, synthesis of ET-1, NO2- and 6-ket-PGF1 alpha increased, expression of FN on the surface of endothelial cells decreased, white blood cells adhesion to endothelial cells increased. There was significant difference between TNF-alpha group and control group. CONCLUSION: TNF-alpha may be involved in the pathogenesis of PIH.

6-Ketoprostaglandin F1 alpha↗

PubMed1999

[Research on stochastic factors of heart rhythm variability in nonlinear dynamic analysis].

In this study, the influence of external noise on heart rhythm variability (HRV) in nonlinear dynamic analysis and the internal stochastic factor of HRV were discussed in connection with their physiological significance. The sampling rate, stationary and non-uniformity time interval were analyzed. An interpolation algorithm for heart period was introduced. The experiment demonstrated that the influence was highly reduced by the mentioned procedure. The internal stochastic factors of HRV were investigated by several nonlinear dynamic methods such as surrogate data, mutual information and nonlinear forecasting. The results suggested the colligation of deterministic chaos and stochastic process should be a favorite to interpret HRV.

Electrocardiography↗

PubMed1999

[Relationship between expression of P16 protein and prognosis in carcinoma of nasopharynx].

We observed the relationship between p16 gene and the occurrence, development and prognosis of carcinoma of nasopharynx by means of LSAB immunohistochemistry method and investigated the expression of protein P16 in 73 cases of carcinoma of nasopharynx and 10 cases of epithelia of chronic inflammation of nasopharynx. The results showed that P16 positive rate was 100% for the epithelia of chronic inflammation of nasopharynx. It was significantly higher than the P16 positive rate for the carcinoma of nasopharynx (38.4%, P < 0.01). There was significant difference of P16 positive expression in differentiation of nasopharyngeal carcinoma (poor differentiation versus undifferentiation), clinical staging (I-II versus IV) and grading of tumor (T1-T2 versus T3, T4) (P < 0.01). There was no correlation between P16 expression and metastatic lymph node (P > 0.05). The 3-year survival rates were 88.9% and 72.9% in P16 expression (+) and (-) patients respectively (P < 0.05). These findings suggested that P16 might play an important role in the process of carcinogenesis and development of nasopharyngeal carcinoma, and P16 might be used as a valuable marker for assessment of the biological behavior and prognosis of nasopharyngeal carcinoma.

Adolescent↗

PubMed1999

[Detection of antineutrophil cytoplasmic autoantibodies in pregnancy induced hypertension and its clinical significance].

OBJECTIVE: To explore the level of antineutrophil cytoplasmic autoantibodies (ANCA) in patients with pregnancy induced hypertension (PIH) and its clinical significance. METHOD: 37 cases with PIH and 39 non-PIH pregnancy were studied for ANCA by indirect immunflourscence. RESULTS: ANCA positive rates were 33.3%, 88.9% and 86.4% in mild, moderate, severe PIH, respectively, and most of them were c-ANCA. The positive rate was only 13.2% in non-PIH control, significantly lower than those in PIH (P < 0.001). CONCLUSION: ANCA may be one of the causes for endothelial cell damage and a predicting marker in PIH.

Adult↗

PubMed1999

[Comparison of vasorelaxing actions of vasonatrin peptide, C-type natriuretic peptide and atrial natriuretic peptide].

The vasorelaxing effects of vasonatrin peptide (VNP), C-type natriuretic peptide (CNP) and atrial natriuretic peptide (ANP) on isolated rat pulmonary artery, abdominal aorta and celiac vein were measured by in vitro perfusion. The results showed that VNP, CNP and ANP caused concentration-dependent relaxation in isolated rat pulmonary artery, abdominal aorta and celiac vein with endothelium or without endothelium. The maximal responses (Rmax) of VNP were (76 +/- 17)%, (51 +/- 14)% and (62 +/- 14)% in pulmonary artery, abdominal aorta and celiac vein with endothelium respectively, whereas those of CNP were (31 +/- 8)%, (22 +/- 7)% and (41 +/- 8)%, and ANP (38 +/- 10)%, (41 +/- 10)% and (11 +/- 4)%. The median effective concentration (EC50) of VNP were 16 +/- 11, 35 +/- 18 and 12 +/- 8 nmol/L in pulmonary artery, abdominal aorta and celiac vein with endothelium respectively, while those of CNP were 148 +/- 112, 299 +/- 84 and 14 +/- 12 nmol/L, and ANP 66 +/- 47, 16 +/- 15 and 909 +/- 445 nmol/L. VNP were more effective than CNP and ANP, and the differences were statistically significant (P < 0.05-0.01). The potency of these peptides for relaxing the blood vessels can be summarized as: VNP > ANP > or = CNP for pulmonary artery; VNP > ANP > CNP for abdominal aorta; VNP > CNP > ANP for celiac vein. There was no significant difference between vessels with intact endothelium and those denuded of endothelium (P > 0.05).

Animals↗

PubMed1999

[Effects of stimulation of dorsal medial area and ventral medial area of nucleus facialis on myoelectric activities of genioglossus and phrenic muscle].

Effects of electrical and chemical stimulation of the dorsal and ventral medial area of nucleus facialis (dMNF and vMNF) on myoelectric activities of genioglossus and phrenic muscle were observed in 44 urethane-anaesthetized and vagotomized rabbits. The results are as follows. (1) Long train electrical stimulation at the dMNF facilitated myoelectric activities of genioglossus and phrenic muscle. (2) Short train electrical stimulation of dMNF, when delivered in the inspiratory phase, caused prolongation of myoelectric activities of genioglossus and phrenic muscle; but when delivered in the expiratory phase, myoelectric activities of genioglossus and phrenic muscle were shortened. (3) Long train electrical stimulation at the vMNF inhibited myoelectric activities of genioglossus and phrenic muscle. (4) Short train electrical stimulation of vMNF caused shortening of myoelectric activities of genioglossus and phrenic muscle, when delivered in the inspiratory phase, but a prolongation when delivered in the expiratory phase. (5) The effects of microinjection of glutamate to dMNF and vMNF were similar to those of electrical stimulation. The above results suggest that both dMNF and vMNF participate in the regulation of the myoelectric activities of genioglossus and the upper airway resistance.

Animals↗

PubMed1999

PCR assay for the inversion causing severe Hemophilia A and its application.

OBJECTIVE: To develop a new technique based on long distance polymerase chain reaction (LD-PCR) to replace Southern blotting method to detect Factor VIII (FVIII) gene inversion leading to severe Hemophilia A (HA) and carrier. METHODS: Four primers P, Q, A&B were designed and synthesized. P&Q is specific for 5' and 3' flanking regions of F8A1 respectively. A&B is specific for 5' and 3' flanking regions of F8A2/F8A3 respectively. LD-PCR with 3 primers and 3 temprature was set up, optimized and used to detect the inversion. RESULTS: The LD-PCR with primers P, Q, A&B, P, Q&B and P, Q&A can be used to detect the gene inversion and discriminate carrier from wild type. A blind analysis of 53 DNA samples from HA families was carried out by the LD-PCR and Southern blotting respectively. Two sets of the results were completely identical. They were 23 cases of inversion, 27 cases of wild type and 3 cases of carriers. The sensitivity and specificity of LD-PCR are both 100%. Three inversion hemizygotes and 4 female carriers were identified from 5 HA families by the LD-PCR technology. CONCLUSIONS: The LD-PCR with primer P, Q&B or P, Q, A&B can be used to detect the gene inversion and the carrier of inversion. Compared with Southern blotting, this technique is simple, rapid, inexpensive, more sensitive, accurate and non-isotopic.

Chromosome Inversion↗