Biomedical subjects

H Lin

Publications and source records attributed to H Lin.

At least 253 records · Page 14Linked to original sources

PubMed1998

[Study on the in vitro and in vivo thrombolytic efficacy of bispecific antifibrin-antiurokinase monoclonal antibodies].

OBJECTIVE: To evaluate the thrombolytic efficacy of bispecfic antifibrin-antiurokinase monoclonal antibodies. METHODS: Murine hybrid hybridomas secreting bispecific monoclonal antibodies (bsMcAbs) were prepared by fusing a mutant hybridomas secreting antifibrin McAbs with spleen cells of murine immunized with urokinase. The binding power of bsMcAbs with fibrin or urokinase was determined by ELISA method. The in vitro thrombolytic efficacy was measured by the dissolving rate of 131I-plasma clot. The in vivo thrombolytic efficacy was measured by using the rabbit jugular vein thrombus model. RESULTS: 8 strains of bsMcAbs have been obtained. ELISA experiments showed that bsMcAbs have very strong binding power with fibrin or urokinase. The bsMcAbs bound with urokinase increased the in vitro thrombolytic efficacy of urokinase by 15.5%. The in vivo thrombolytic efficacy of bsMcAbs bound with urokinase was 1.6-2.1 times as high as urokinase. CONCLUSIONS: Monoclonal antibody-directed thrombolytic agents have advantages of high specificity and strong local thrombolytic efficacy. It is well worth going on further study.

Animals↗

PubMed1998

[Multiple subpial transection in surgical treatment of intractable epilepsy].

OBJECTIVE: To increase the effect of epilepsy surgery, we use multiple subpial transection (MST) clinically on the basis of experimental study. METHOD: We analyzed the seizure type and course of 116 intractable epilepsy patients treated with MST and surgical technique were modified. RESULT: 100 patients were followed up for 1 to 5 years. Complete control of seizure was obtained in 62 patients (62%), significant reduction (over 75%) in 20 (20%), reduction (over 50%) in 12 (12%), and no change in 6 (6%). The total effective rate was 94%, and the significant effective rate was 82%. No functional defect was found in any patients. CONCLUSION: MST is a effective in surgical treatment of intractable epilepsy and can replace conventional methods. Combined bilateral frontal lobe MST and anterior callosotomy is a good way to treat intractable generalized epilepsy.

Adolescent↗

PubMed1998

[Clinical diagnostic standard of mediopatellar plica syndrome].

OBJECTIVE: To increase the level of clinical diagnosis of mediopatellar plica syndrome. METHOD: We reviewed the preoperative clinical symptoms of 67 knee joints that were proved to have pathologic mediopatellar plica by arthroscopy. RESULT: Mediopatellar plica syndrome had the following clinical symptoms: painful knee and mediopatellar tenderness in all patients; tender bands in 56.7% patients; positive test of flexion or extension with internal femoral condyle pressed in 62.7% patients; positive Mcmarry's sign in 31.3% patients. CONCLUSION: The clinical diagnostic standard of mediopatellar plica syndrome is that the first above-mentioned clinical symptom plus one of other three symptoms could suggest the diagnosis, while the first clinical symptom plus two or three of other three symptoms could define the diagnosis.

Adult↗

PubMed1998

[The detection of breast carcinoma micrometastases in axillary lymph nodes by reverse transcriptase-polymerase chain reaction].

OBJECTIVE: To detect tumor micrometastases in axillary lymph nodes of breast carcinoma so as to obtain more reliable information about nodes status and its clinical significance. METHOD: The expression of CK19 mRNA was measured in 61 axillary lymph nodes (LNs) of 15 breast carcinomas by using reverse transcriptase-polymerase chain reaction (RT-PCR). RESULT: CK19 mRNA expression was detected in all 15 breast carcinomas, but not in 5 control LNs. Of 61 axillary LNs analysed by HE staining and CK19 RT-PCR, 7 LNs were found to have metastases by histological staining and CK19 RT-PCR. Of the remaining 54 axillary nodes, 12 were found to have metastases by using CK19 RT-PCR method. CONCLUSION: The CK19 RT-PCR method is more sensitive than histological study for the detection of micrometastases in LNs (P < 0.01). This new method is of value in differentiating breast cancer patients at high risk for relapse from those with negative lymph node.

Axilla↗

PubMed1998

[Identification of Chinese drug sea coconut].

Sea Coconut is the seed of Lodoicea maldivica Persoon, palmae. It is one species in the Seychelles Islands, Africa. The drug is yellow-white in colour, slice-shaped, 12 cm in length and 4 cm in breadth. Seed-coat cell circular in shape. Under seed-coat, the cells are elliptic, and stone cells are rectangle with thick wall and large pit. Endosperm cell elongate with thick wall and large pits, the end of pits enlarge as a pearl.

Arecaceae↗

PubMed1998

[A correlate study on the first cervical vertebra and mandibular growth:A comparison of Shanghai females between 12 and 15 years old]

OBJECTIVE:To study the correlation between the cervical vertebra and mandibular growth and to reveal the intrinsic rule of the progress of individual growth, especially the trend of craniofacial development.METHODS:The morphological features of the first cervical vertebra and certain variables of craniofacial in lateral cephalometric radiographs from Shanghai females between 12 and 15 years old were measured and correlated. A set of normal values of the atlas vertebra shape of Shanghai 12 and 15 years old females were established.RESULTS:There was a significant correlation between D1 and AP of the first cervical vertebra and the direction of mandibular growth at the age of 12. But the association between atlas size ratio (AP/D1) and the mandibular growth is more notable than either AP or D1. When the atlas size ratio increased, a reduction of the amount of mandibular horizontal growth was showed, and the mandibular rotated backward; on the contrary, when the atlas size ratio decreased, the amount of mandibular horizontal growth increased and the mandibular rotated forward. CONCLUSION: The first cervical vertebra can be used as an indicator to predict the mandibular growth.

Journal Article↗

PubMed1998

[Study on the maturation of cervical vertebra for 208 cases Shanghai adolescents growth]

OBJECTIVE:To establish a set of normal values of maturation stages of cervical vertebra for Shanghai adolescents and to provide valid reference index for assessing skeletal age while making diagnosis and treatment plan.METHODS:208 Shanghai adolescents from 11 to 15 years of age were investigated by lateral cephalometric radiographs. The growth status and the relationship of C2-C5 cervical vertebra were observed. RESULTS:The anterior and posterior vertical heights and areas of C2-C5 cervical vertebra increased progressively along with the age, the shapes of cervical vertebra bodies varied regularly. Although female goes into the young quick growing period 2 years earlier than male, the shape changes have no difference between gender. The established standard values of maturation stages of cervical vertebra for Shanghai 11-15 years old adolescents revealed that the growth and development of Shanghai adolescents are getting earlier when comparing with that of GuangDong province. CONCLUSION: The morphological variation of cervical vertebra can be used as an indicator of skeletal age to determine adolescents' growth and development status.

Journal Article↗

PubMed1998

Integrin alphavbeta5 participates in the binding of photoreceptor rod outer segments during phagocytosis by cultured human retinal pigment epithelium.

PURPOSE: To examine the expression of integrin vitronectin receptors (integrins alphavbeta3 and alphavbeta5) in native human fetal retinal pigment epithelium (RPE) and cultured hunman fetal RPE and to examine the role of RPE VnRs in the phagocytosis of photoreceptor rod outer segments (ROS). METHODS: Monoclonal antibodies against human integrin subunit alphav and heterodimers alphavbeta3 (LM609) and alphavbeta5 (P1F6) were used to label freshly isolated human fetal RPE explant and cultured human fetal RPE and to immunoprecipitate membrane proteins from cultured human RPE. Effects of antibodies and peptides that inhibit integrin vitronectin receptors on phagocytosis of ROS by RPE were determined using cultured human fetal RPE and fluorescein-labeled bovine outer segments. RESULTS: Antibodies against integrin subunit alphav and against alphavbeta5 (P1F6) labeled the RPE apical membrane in both native tissue and cultured RPE, while anti-alphavbeta3 antibody (LM609) labeled less than 1% of cultured RPE and did not label native RPE. Antibodies against alphav and alphavbeta5 P1F6 also immunoprecipitated 2 protein bands corresponding to integrin subunits alphav and beta5 from a membrane extract of cultured human RPE. The peptide Gly-Arg-Gly-Asp-Ser-Pro (GRGDSP, 1 mM) inhibited the total ROS uptake (externally bound and ingested) by 48% (P < 0.001) and ingestion of ROS by 37% (P < 0.001). Antibody PIF6 (50 microg/ml) inhibited the total ROS uptake and the ingestion of ROS by 63% (P < 0.001) and 43% (P < 0.01), respectively. CONCLUSIONS: The integrin alphavbeta5 vitronectin receptor is expressed on the apical membrane of human RPE and participates in the binding of photoreceptor ROS during phagocytosis by cultured human RPE.

Animals↗

PubMed1998

Allelic deletion analyses of MMAC/PTEN and DMBT1 loci in gliomas: relationship to prognostic significance.

The frequency of loss of heterozygosity (LOH) around MMAC/PTEN and DMBT1 loci and survival analyses based on the LOH status were assessed in 110 patients with different histological groups of gliomas. Twenty-six of the patients had anaplastic oligodendrogliomas, 31 had anaplastic astrocytomas, and 53 had glioblastomas multiforme (GM). At the DMBT1 locus, LOH was observed very frequently in all three histological groups, with no significant difference in the frequency of LOH among the three histological groups. At the MMAC/PTEN locus, patients with GM exhibited a significantly increased frequency of LOH (72%) compared with patients with anaplastic astrocytomas (29%) or anaplastic oligodendrogliomas (31%) (P < 0.0001). Kaplan-Meier survival plots showed that patients with LOH at the MMAC/PTEN locus had a significantly worse prognosis than did patients without LOH at the MMAC/PTEN locus [hazard ratio (LOH versus non-LOH), 2.65; 95% confidence interval (CI), 1.69-4.46; P < 0.0001]. Cox proportional hazards regression analysis, adjusted for age at surgery and histological grades (GM and non-GM), showed that LOH at the MMAC/PTEN locus was a significant predictor of shorter survival [hazard ratio (LOH versus non-LOH), 2.01; 95% CI, 1.1-3.5; P = 0.018). Our analysis failed to indicate a similar association between the frequency of LOH at the DMBT1 locus and patient survival [hazard ratio (LOH versus non-LOH), 2; 95% CI, 0.37-3.13; P = 0.2]. These results suggest that the DMBT1 gene may be involved early in the oncogenesis of gliomas, whereas alterations in the MMAC/PTEN gene may be a late event in the oncogenesis related to progression of gliomas and provide a significant prognostic marker for patient survival.

Agglutinins↗

PubMed1998

Synthesis and biological activity of binuclear platinum complexes containing two monofunctional cis-[Pt(NH3)2Cl]+ units bridged by 4,4'-dipyridyl selenides or sulfides.

The synthesis of four binuclear platinum complexes of general formula ¿cis-[Pt(NH3)2Cl]2(L)¿ (NO3)2 [L is 4,4'-dipyridyl sulfide (compound I), 4,4'-dipyridyl selenide (compound II), bis(3-methyl-4-pyridyl) sulfide (compound III) or bis(3-methyl-4-pyridyl) selenide (compound IV)] has been achieved. These compounds have been characterized by elemental analysis, IR, 1H-NMR, 13C-NMR and 195Pt-NMR spectroscopy. The above dinuclear platinum complexes have been assayed for antitumor activity in vitro against the cisplatin-sensitive L1210 (the mice leukemia) and cisplatin-insensitive HCT8 (the human coloadenocarcinoma) cell lines. The compounds show IC50 values comparable to or higher than cisplatin against L1210 cell line; however, they have lower IC50 values than cisplatin against the cisplatin-insensitive HCT8 cell line. The complexes containing S exhibit a cytotoxicity against the two cancer cell lines superior to the Se analogues. DNA binding studies indicate the compound I possibly interacts with DNA nonintercalatively. The mode of DNA binding of the dinuclear Pt(II) complexes bridged by 4,4'-dipyridyl selenides or sulfides may be different to that of the aliphatic diaminebridged dinuclear Pt(II) complexes reported previously.

Animals↗

PubMed1998

Estrogen receptors and glucocorticoid receptors in human well-differentiated thyroid cancer.

Previously, we and others have found that the prognosis of patients with well differentiated thyroid cancer is related to patient age and gender. In this study, we examined estrogen and glucocorticoid receptors in thyroid cancers and adjacent non-neoplastic thyroid tissues from 31 Chinese patients. Our results indicate that the level of estrogen and glucocorticoid receptors in thyroid cancer tissues was similar to that in non-neoplastic thyroid tissues. Significant higher estrogen and glucocorticoid receptor levels were found in thyroid cancers from men than women. There was no difference in estrogen receptor levels from thyroid cancer in women less than or older than 45. However, the level of glucocorticoid receptor in thyroid cancer from women less than 45 years old was significantly higher than that of women older than 45. Estrogen or glucocorticoid receptor levels did not correlate with tumor invasiveness. The pathobiological role of glucocorticoid receptors in thyroid cancer is not known but may be involved in changes in circadian rhythm of thyroid tumors.

Journal Article↗

PubMed1997

MMAC1/PTEN mutations in primary tumor specimens and tumor cell lines.

A candidate tumor suppressor gene, MMAC1/PTEN, located in human chromosome band 10q23, was recently identified based on sequence alterations observed in several glioma, breast, prostate, and kidney tumor specimens or cell lines. To further investigate the mutational profile of this gene in human cancers, we examined a large set of human tumor specimens and cancer cell lines of many types for 10q23 allelic losses and MMAC1 sequence alterations. Loss of heterozygosity (LOH) at the MMAC1 locus was observed in approximately one-half of the samples examined, consistent with the high frequency of 10q allelic loss reported for many cancers. Of 124 tumor specimens exhibiting LOH that have been screened for MMAC1 alterations to date, we have detected variants in 13 (approximately 10%) of these primary tumors; the highest frequency of variants was found in glioblastoma specimens (approximately 23%). Novel alterations identified in this gene include a missense variant in a melanoma sample and a splicing variant and a nonsense mutation in pediatric glioblastomas. Of 76 tumor cell lines prescreened for probable LOH, microsequence alterations of MMAC1 were detected in 12 (approximately 16%) of the lines, including those derived from astrocytoma, leukemia, and melanoma tumors, as well as bladder, breast, lung, prostate, submaxillary gland, and testis carcinomas. In addition, in this set of tumor cell lines, we detected 11 (approximately 14%) homozygous deletions that eliminated coding portions of MMAC1, a class of abnormality not detected by our methods in primary tumors. These data support the occurrence of inactivating MMAC1 alterations in multiple human cancer types. In addition, we report the discovery of a putative pseudogene of MMAC1 localized on chromosome 9.

Brain Neoplasms↗

PubMed1997

Growth suppression of glioma cells by PTEN requires a functional phosphatase catalytic domain.

Deletions of all or part of chromosome 10 are the most common genetic alterations in high-grade gliomas. The PTEN gene (also called MMAC1 and TEP1) maps to chromosome region 10q23 and has been implicated as a target of alteration in gliomas and also in other cancers such as those of the breast, prostate, and kidney. Here we sought to provide a functional test of its candidacy as a growth suppressor in glioma cells. We used a combination of Northern blot analysis, protein truncation assays, and sequence analysis to determine the types and frequency of PTEN mutations in glioma cell lines so that we could define appropriate recipients to assess the growth suppressive function of PTEN by gene transfer. Introduction of wild-type PTEN into glioma cells containing endogenous mutant alleles caused growth suppression, but was without effect in cells containing endogenous wild-type PTEN. The ectopic expression of PTEN alleles, which carried mutations found in primary tumors and have been shown or are expected to inactivate its phosphatase activity, caused little growth suppression. These data strongly suggest that PTEN is a protein phosphatase that exhibits functional and specific growth-suppressing activity.

Brain Neoplasms↗

PubMed1997

Electromagnetic field exposure induces rapid, transitory heat shock factor activation in human cells.

Stimulation of human promyelocytic HL60 cells by a 60Hz magnetic field at normal growth temperatures results in heat shock factor 1 activation and heat shock element binding, a sequence of events that mediates the stress-induced transcription of the stress gene HSP70 and increased synthesis of the stress response protein hsp70kD. Thus, the events mediating the electromagnetic field-stimulated stress response appear to be similar to those reported for other physiological stresses (e.g., hyperthermia, heavy metals, oxidative stress) and could well be the general mechanism of interaction of electromagnetic fields with cells.

Binding Sites↗

PubMed1997

Spectrosomes and fusomes anchor mitotic spindles during asymmetric germ cell divisions and facilitate the formation of a polarized microtubule array for oocyte specification in Drosophila.

In the Drosophila ovary, membrane skeletal proteins such as the adducin-like Hts protein(s), spectrin, and ankyrin are found in the spectrosome, an organelle in germline stem cells (GSC) and their differentiated daughter cells (cystoblasts). These proteins are also components of the fusome, a cytoplasmic structure that spans the cystoblast's progeny that develop to form a germline cyst consisting of 15 nurse cells and an oocyte. Spectrosomes and fusomes are associated with one pole of spindles during mitosis and are implicated in cyst formation and oocyte differentiation. Here we show that the asymmetric behavior of the spectrosome persists throughout the cell cycle of GSC. Eliminating the spectrosome by the htsl mutation leads to randomized spindle orientation, suggesting that the spectrosome anchors the spindle to ensure the asymmetry of GSC division; eliminating the fusome in developing cysts results in defective spindles and randomized spindle orientation as well as asynchronous and reduced cystocyte divisions. These observations suggest that fusomes are required for the proper formation and asymmetric orientation of mitotic spindles. Moreover, they reinforce the notion that fusomes are required for the four synchronous divisions of the cystoblast leading to cyst formation. In htsl cysts which lack fusomes and fail to incorporate a hts gene product(s) into ring canals following cyst formation, polarized microtubule networks do not form, the dynamics of cytoplasmic dynein is disrupted, and oskar and orb RNAs fail to be transported to the future oocyte. These observations support the proposed role of fusomes and ring canals in organizing a polarized microtubule-based transport system for RNA localization that leads to oocyte differentiation.

Animals↗

PubMed1997

Cryogenic frozen solution matrixes for analysis of DNA by time-of-flight mass spectrometry.

We present an alternative matrix system for mass analysis of high molecular weight biomolecules by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS). Single-stranded DNA oligomers are embedded in thin films of frozen solutions containing photoabsorbing substituted phenols. Ultraviolet laser desorption from these cryogenically cooled matrixes generates internally colder ions than from the equivalent room-temperature crystalline matrixes containing no solvent, as evidenced by a substantial reduction in the extent of fragmentation in the corresponding mass spectra of oligonucleotides. Furthermore, the homogeneity of the frozen solution samples allows analyte signals to be obtained uniformly throughout the sample. Sensitivity and mass resolution approaching that obtained using the most effective room-temperature crystalline matrix for DNA (3-hydroxypicolinic acid) are consistently and reproducibly obtained in both positive and negative ion mass spectra. As fragmentation is a principle factor limiting the maximum attainable mass resolution in MALDI-TOF mass analysis of DNA, this improvement in generating intact DNA ions is advantageous.

DNA↗

PubMed1997

Transcriptional targeting of replication-defective adenovirus transgene expression to smooth muscle cells in vivo.

Gene transfer using replication-defective adenoviruses (RDAd) holds promise for the treatment of vascular proliferative disorders, but is potentially limited by the capacity of these viruses to infect multiple cell lineages. We have generated an RDAd vector, designated AdSM22-lacZ, which encodes the bacterial lacZ reporter gene under the transcriptional control of the smooth muscle cell (SMC)-specific SM22alpha promoter. Here, we show that in vitro AdSM22-lacZ programs expression of the lacZ reporter gene in primary rat aortic SMCs and immortalized A7r5 SMCs, but not in primary human umbilical vein endothelial cells (HUVECs) or NIH 3T3 cells. Consistent with these results, after intraarterial administration of AdSM22-lacZ to control and balloon-injured rat carotid arteries, beta-galactosidase activity was detected within SMCs of the tunica media and neointima, but not within endothelial or adventitial cells. Moreover, intravenous administration of AdSM22-lacZ did not result in lacZ gene expression in the liver or lungs. Finally, we have shown that direct injection of AdSM22-lacZ into SMC-containing tissues such as the ureter and bladder results in high-level transgene expression in visceral SMCs. Taken together, these results demonstrate that transgene expression after infection with an RDAd vector can be regulated in an SMC lineage-restricted fashion by using a transcriptional cassette containing the SMC-specific SM22alpha promoter. The demonstration of an efficient gene delivery system targeted specifically to SMCs provides a novel means to restrict expression of recombinant gene products to vascular or visceral SMCs in vivo.

Adenoviridae↗

PubMed1997

Influence of the positions of cis double bonds in the sn-2-acyl chain of phosphatidylethanolamine on the bilayer's melting behavior.

In an attempt to examine the effects of different numbers and positions of cis double bonds in the sn-2-acyl chain of phosphatidylethanolamine (PE) on the bilayer's melting behavior, 21 molecular species of PE were first semisynthesized, and their Tm and DeltaH values were subsequently determined by high resolution differential scanning calorimetry. In the plot of Tm versus the number of the cis double bond, some characteristic profiles were observed for the various series of PEs. For instance, if the cis double bond was first introduced into the sn-2-acyl chain of C(20):C(20)PE at the Delta5-position, the Tm was observed to reduce drastically. Subsequent stepwise additions of up to five cis double bonds at the methylene-interrupted positions toward the methyl end resulted in a progressive yet smaller decrease in Tm. If, on the other hand, the cis double bonds were introduced sequentially at the Delta11-, Delta11,14-, and Delta11,14,17-positions along the sn-2-acyl chain of C(20):C(20)PE, the Tm profile in the Tm versus the number of the cis double bond showed a down-and-up trend. Most interestingly, for positional isomers of C(20):C(20:3Delta5,8,11)PE, C(20):C(20:3Delta8,11,14)PE, and C(20):C(20:3Delta11,14,17)PE, an inverted bell-shaped Tm profile was detected in the plot of Tm against the position of the omega-carbon for these isomers. Similar Tm profiles were also observed for C(18):C(20)PE, C(20):C(18)PE, and their unsaturated derivatives. This work thus demonstrated that both the positions and the numbers of cis double bonds in the sn-2 acyl chain could exert noticeable influence on the gel-to-liquid crystalline phase transition behavior of the lipid bilayer. Finally, a molecular model was presented, with which the behavior of the gel-to-liquid crystalline phase transition observed for lipid bilayers composed of various sn-1-saturated/sn-2-unsaturated lipids can be rationalized.

Acylation↗