Biomedical subjects

L Yin

Publications and source records attributed to L Yin.

At least 109 records · Page 6Linked to original sources

PubMed1998

[VP-16 and VM-26 plus platinum drugs combined with radiotherapy in the treatment of small cell lung cancer].

OBJECTIVE: To compare the clinical efficacy of VP-16(etoposide) with VM-26(teniposide) both plus platinum drugs combined with radiotherapy in the treatment of patients with small cell lung cancer(SCLC). METHODS: Seventy-four cases of SCLC were studied retrospectively. Forty-three patients were treated with VP-16 + DDP + CTX or VP-16 + DDP, the other 31 patients were treated with VM-26 + DDP or VM-26 + Carboplatin. The treatment of both groups was combined with radiotherapy. RESULTS: There was no significant difference between VP-16 and VM-26 groups in response rate, 2-year-survival rate, and brain metastasis rate. But the blood toxicity was more serious in VM-26 group than in VP-16 group; 3-4 stage toxicity rate was 58.06% versus 27.91%. CONCLUSION: The results indicate that both VP-16 and VM-26 combined with platinum drugs were effective chemotherapy protocols. The authors suggest choosing VP-16 protocols as the first choice for previously untreated SCLC patients.

Adult↗

PubMed1998

[Diagnosis and endovascular treatment of multiple thrombosis in cerebral venous sinus].

OBJECTIVE: To study 12 cases of multiple thrombosis in cerebral venous sinuses and the diagnosis and endovascular therapy. METHOD: The long T2 and short T1 signals in the related region of multiple venous sinuses on MR were important characteristics for the diagnosis before angiography. In the 12 cases, the treatment consisted of intermittent injection of urokinase via common carotid artery and oral administration of warfarin. RESULTS: Intracranial pressure of 11 cases reduced to lower than 300 mm H2O and clinical deficits were markedly improved in 10 days. Re-angiography of 4 cases found partial recanalization in 2 in one week after therapy. CONCLUSION: Intraoarterial thrombolysis combined with general anticoagulation in the treatment of multiple thrombosis in cerebral venous sinuses may be an effective meansure.

Adolescent↗

PubMed1998

[Effect of recombinant human growth hormone with total parenteral nutrition on albumin synthesis in patients with peritoneal sepsis].

OBJECTIVE: To investigate the effect of recombinant human growth hormone (rhGH) in combination with total parenteral nutrition (TPN) on albumin synthesis in patients with peritoneal sepsis. METHOD: 17 patients with peritoneal sepsis were divided randomly into two groups. The control group received TPN only for 7 days, and the GH group received both rhGH (12 U/d) and TPN for 7 days. The TPN scheme and other treatment were the same in the two groups. RESULT: Serum albumin, prealbumin, and transferrin concentration were increased in patients in the GH group (P < 0.01), but no apparent effect was observed in the control group (P > 0.05). CONCLUSION: In condition of serious peritoneal sepsis, TPN can not increase albumin, prealbumin, and transferrin synthesis alone, whereas rhGH in combination with TPN significantly increase the synthesis of visceral proteins.

Adolescent↗

PubMed1998

Effect of testosterone on Leishmania donovani infection levels of murine bone marrow derived-macrophages.

AIM: To investigate the effect of the male sex hormone, testosterone (Te), on Leishmania donovani infection levels of bone marrow derived macrophages(BMMs) from female mice of strain C57BL/6J. METHODS: After three weeks of Te-treatment, the BMMs were isolated, challenged with L. donovani at a ratio of 10 to 1 promastigotes per macrophage, and the infection levels of different time points were monitored by Giemsa staining. RESULTS: BMMs from Te-treated mice had a significantly increased initial uptake(3 h post infection, P < 0.05) of promastigotes and carried heavier infection levels at all time points(24 h, 48 h, 72 h post infection, P < 0.01), compared with those from oil treated controls. CONCLUSION: Te can increase L. donovani infection levels of BMMs, being possibly related to Te-induced immunosuppression.

Animals↗

PubMed1997

The morphology of the immature HIV-1 virion.

Newly released HIV-1 particles exhibit an immature morphology, previously reported to be characterized by a doughnut/ring-shaped structure. In this study we showed that among immature extracellular virus particles not only were particles with doughnut-shaped morphology present, but particles with a crescent morphology were also observed. These particles occurred with different frequencies, depending on whether they were in the cell or in cell-free fractions. The crescent-shaped particles were more abundant in the cell-free fractions, whereas the particles in the cell fraction mainly exhibited doughnut-shaped morphology. The crescent-shaped structure may represent an assembly intermediate.

Cell Line, Transformed↗

PubMed1997

Apoptotic condensations in M-phase cells.

BACKGROUND: Apoptosis is a morphologically distinctive form of programmed cell death/cell suicide in which genomic DNA degradation/fragmentation and variegated dense chromatin aggregates are characteristic hallmarks that have never been demonstrated in mitotic cells. Perceptions of mutual exclusivity between apoptosis and mitosis imply that M-phase cells cannot be apoptotic. However, in the present study we show apoptotic morphologies in M-phase cells after an acute oxidative stress and endonuclease digestion. METHODS: Degradation of genomic DNA in human Chang liver cells (American Type Culture Collection, ATCC CCL13) was demonstrated by flow cytometric cell-by-cell evaluation of (a) propidium iodide intercalative binding to DNA and (b) terminal deoxynucleotidyl transferase (TdT)-mediated 3'OH nick end labeling (TUNEL) of fragmented DNA. Oxidative stress was imposed by a 30-min prepulse with 200 microM vanadyl(4), which produces hydroxyl free radicals (OH*), the most reactive of the free radical species. Oxidative stress in the cells was demonstrated by evaluating glutathione-S-transferase (GST)-mediated monochlorobimane-glutathione adduct fluorescence for glutathione content, the main reducing agent of a cell, and methylene blue redox metachromasia, which is a deep color when oxidized and colorless when reduced. Cells with DNA fragmentation were highlighted by TUNEL. Apoptotic morphologies were visualized by staining with Giemsa and neutral red dyes and by DNA-propidium iodide binding to chromatin. Direct endonuclease induction of apoptotic morphologies in permeabilized M-phase cells was produced by 1 hr incubation (37 degrees C) with 16 units/ml of micrococcal nuclease. RESULTS: The genomic DNA of proliferative cells, namely in G2/M phase of the cell cycle, was degraded by vanadyl(4) prepulsing and by micrococcal nuclease digestion, concomitantly with DNA fragmentation shown by TUNEL. Cytological profiles showed GSH depletion and M-phase cells with particularly high oxidative reactivity indicated by methylene blue redox metachromasia. DNA fragmentation in M-phase cells was highlighted by TUNEL. Characteristic apoptotic condensations, ranging from single-ball condensations to "pulverized" aggregates of a mitotic catastrophe, buddings, and "apoptotic bodies," were found in prophase, metaphase, anaphase, and telophase mitotic cells. The observed separation of condensed chromatin aggregates from the main chromosome mass in prophase and metaphase cells could explain micronuclei, linking it with apoptosis. Direct endonuclease digestion readily produced apoptotic morphologies in interphase and in M-phase cells. CONCLUSION: Apoptotic morphologies in M-phase cells can be induced indirectly via oxidative stress or directly via endonuclease activity, which has long been established as a pervading hallmark of apoptosis.

Apoptosis↗

PubMed1997

Frequency of RET mutations in long- and short-segment Hirschsprung disease.

Hirschsprung disease, or congenital aganglionic megacolon, is a genetic disorder of neural crest development affecting 1:5,000 newborns. Mutations in the RET proto-oncogene, repeatedly identified in the heterozygous state in both long- and short-segment Hirschsprung patients, lead to loss of both transforming and differentiating capacities of the activated RET through a dominant negative effect when expressed in appropriate cellular systems. The approach of single-strand conformational polymorphism analysis established for all the 20 exons of the RET proto-oncogene, and previously used to screen for point mutations in Hirschsprung patients allowed us to identify seven additional mutations among 39 sporadic and familial cases of Hirschsprung disease (detection rate 18%). This relatively low efficiency in detecting mutations of RET in Hirschsprung patients cannot be accounted by the hypothesis of genetic heterogeneity, which is not supported by the results of linkage analysis in the pedigrees analyzed so far. Almost 74% of the point mutations in our series, as well as in other patient series, were identified among long segment patients, who represented only 25% of our patient population. The finding of a C620R substitution in a patient affected with total colonic aganglionosis confirms the involvement of this mutation in the pathogenesis of different phenotypes (i.e., medullary thyroid carcinoma and Hirschsprung). Finally the R313Q mutation identified for the first time in homozygosity in a child born of consanguineous parents is associated with the most severe Hirschsprung phenotype (total colonic aganglionosis with small bowel involvement).

DNA Mutational Analysis↗

PubMed1997

Immune responses in mice deficient in Ly-GDI, a lymphoid-specific regulator of Rho GTPases.

Ly-GDI (lymphoid-specific guanosine diphosphate (GDP) dissociation inhibitor), also called D4-GDI, is preferentially expressed in hematopoietic tissues including bone marrow, thymus, spleen and lymph nodes. It binds to the small guanosine triphosphate (GTP)-binding protein Rho and inhibits GDP dissociation from Rho proteins. To explore the function of Ly-GDI in lymphocytes, we have generated Ly-GDI-deficient mice by gene targeting. These mice showed no striking abnormalities of lymphoid development or thymocyte selection. The mice also exhibited, for the most part, normal immune responses including lymphocyte proliferation, IL-2 production, cytotoxic T lymphocyte activity, antibody production, antigen processing and presentation, immune cell aggregation and migration, and protection against an intracellular protozoan. However, Ly-GDI-deficient mice exhibited deregulated T and B cell interactions after in vitro cultivation of mixed lymphocyte populations in concanavalin A (Con A) leading to overexpansion of B lymphocytes. Further studies revealed that Ly-GDI deficiency decreased IL-2 withdrawal apoptosis of lymph node cells while dexamethasone- and T cell receptor-induced apoptosis remained intact. These data implicate the regulation of the Rho GTPase by Ly-GDI in lymphocyte survival and responsiveness, but suggest that these functions may be partially complemented by other Rho regulatory proteins when the Ly-GDI protein is deficient.

Animals↗

PubMed1997

Micrococcal nuclease (endonuclease) digestion causes apoptosis and mitotic catastrophe with interphase chromosome condensation in human Chang liver cells.

Endonuclease activation causing genomic degradation is a pervasive hallmark of apoptosis and a suggested precipitating or commitment step in the suicidal process. Directly applied endonuclease activity has produced apoptotic-like effects in isolated nuclei, but not yet shown as an initiating apoptogen in whole cells. Mechanistically genomic damage inflicted by a variety of DNA-damaging agents is also known to produce mitotic catastrophe condensations characterizing cell cycle derangement. Morphological and molecular similarities between apoptosis and mitotic catastrophe have been noted, but their conjoint expressions from directly applied endonuclease activity has also not been shown. We show here micrococcal nuclease (MNase) initiating apoptosis in human Chang liver cells which expressed both apoptotic and mitotic catastrophe condensations. Genomic profiling showed (a) the two stage apoptotic sequence of large (50 kb) and small (200 bp) fragment cleavage demonstrated by pulse field and normal gel electrophoresis, respectively; (b) the sub-G1 ;apoptotic peak' with shrunken cells from flow cytometric evaluation of PI-DNA binding and laser forward scattering, (c) 3' OH termini typical of apoptotic DNA fragments labelled by terminal deoxynucleotidyl transferase (TdT)-mediated fluorescence tagging especially in the shrunken cells, and (d) positive comet assay of the apoptotic genome. Nuclear shrinkage evaluated by confocal image analysis was consistent with the apoptotic response, as was Zn2+ ion sensitivity, an established inhibitor of apoptotic expression. Endonuclease activity per se is apoptogenetic and mechanistically convergent with the mitotic catastrophe pathway in the proliferative cycle.

Journal Article↗

PubMed1997

[Spectrophotometric method for determination of protein in food with Hantzsch reaction].

A new spectrophotometric method for the determination of protein in food was developed. The method is based on the reaction of ammonia in Kjeldahl digest with acetylacetone for maldehyde reagent in pH4.8 acetate medium to yield a yellow compound 3,5-diacetyl-2,6-dimethyl-1,4-dihydropyridine. Beer's law is obeyed in the concentration range of 0-10.0 mg/L at 400 nm. The molar absorptivity in terms of nitrogen was 1.7 x 10(-3). The recoverites of the added standard samples were 99.6%-101.2%, and relative standard deviation was below 3.7%.

Dietary Proteins↗

PubMed1997

[Influence of intercellular adhesion molecule-1 transcription on nasal epithelial cell by airborne allergenic pollens].

Eleven patients with Artemisia allergic rhinitis were evaluated. Among them 8 were studied during pollen season and 3 out of pollen season. Intercellular adhesion molecule-1(ICAM-1) was detected on nasal epithelial cells by reverse transcription polymerase chain reaction (RT-PCR). The results showed that ICAM-1 was detectable from all samples in the pollen season. However, during off-pollen season 2 of the 3 samples were negative, 1 was positive (who was also positive to house dust). It is suggested that ICAM-1 is detectable on nasal epithelial cells during exposure to specific allergen.

Adolescent↗

PubMed1997

[Inherent mdr-1 gene expression in fresh tumor tissue specimens from several high-incidence malignancies].

OBJECTIVE: To ascertain frequency of inherent mdr-1 gene expression in several common neoplasms. METHODS: One hundred fifty one surgically resected tumor specimens confirmed pathologically to be malignant from preoperatively untreated cancer patients were studied. Expression of mdr-1 gene was examined by RT-PCR. RESULTS: The frequency of primary mdr-1 gene expression was 33.3% for cancer of the stomach and gastric cardia (17/51), 37% for cancer of the esophagus (17/46), 31.3% for cancer of the colon and rectum (5/16), 13.2% for cancer of the breast (2/15), 40.0% for cancer of the thyroid (4/10), 55.0% for cancer of the lung (5/9) and 0% for cancer of the uterine cervix (0/4). CONCLUSION: Primary mdr-1 gene expression is relatively of frequent occurrence as detected by RT-PCR technique.

Adenocarcinoma↗

PubMed1996

The role of Gag in human immunodeficiency virus type 1 virion morphogenesis and early steps of the viral life cycle.

The phenotypes of a series of mutant human immunodeficiency virus type 1 proviruses with linker insertion and deletion mutations within the gag coding region were characterized. These mutants, with mutations in the matrix, capsid, and p2 coding regions, produced replication-defective virion particles with defects in the early steps of the viral life cycle. To investigate this phenotype further, the abilities of mutant virion particles to enter T cells, initiate and complete reverse transcription, and transport the newly transcribed proviral DNA were investigated. Only 4 of 10 of the mutants appeared to make wild-type levels of viral DNA. Biochemical analyses of the mutants revealed the middle region of CA as being important in determining virion particle density and sedimentation in velocity gradients. This region also appears to be critical in determining the morphology of mature virion particles by electron microscopy. Particles with aberrant morphology were uninfectious, and only those mutants which displayed cone-shaped cores were capable of carrying out the early steps of the viral life cycle. Thus, the normal morphology of human immunodeficiency virus type 1 appears to be critical to infectivity.

Animals↗

PubMed1996

Cyclosporine A-resistant human immunodeficiency virus type 1 mutants demonstrate that Gag encodes the functional target of cyclophilin A.

The cellular peptidyl-prolyl isomerase cyclophilin A is incorporated into human immunodeficiency virus type 1 virions via contacts with the proline-rich domain of the Gag polyprotein. Cyclosporine A and nonimmunosuppressive analogs bind with high affinity to cyclophilin A, compete with Gag for binding to cyclophilin A, and prevent incorporation of cyclophilin A into virions; in parallel with the disruption of cyclophilin A incorporation into virions, there is a linear reduction in the initiation of reverse transcription after infection of a T cell. Passage of human immunodeficiency virus type 1 in the presence of the drug selects one of two mutations, either of which alters the proline-rich domain of Gag and is sufficient to confer drug resistance on the cloned wild-type provirus. Neither mutation alters Gag's cyclophilin A-binding properties in vitro, and cyclophilin A incorporation into drug-resistant virions is effectively disrupted by cyclosporine A, indicating that the drug-resistant mutants do not require virion-associated cyclophilin A to initiate infection. That Gag's functional dependence on cyclophilin A can be differentiated genetically from its ability to bind cyclophilin A is further demonstrated by the rescue of a mutation precluding cyclophilin A packaging by a mutation conferring cyclosporine A resistance. These experiments demonstrate that, in addition to its ability to package cyclophilin A into virions, gag encodes the functional target of cyclophilin A.

Acquired Immunodeficiency Syndrome↗

PubMed1996

MoSearch: a radiologist-friendly tool for finding-based diagnostic report and image retrieval.

The diagnostic reports generated in a radiology department contain a wealth of information. Although radiology information systems can greatly facilitate patient-based access to this information, they typically provide only limited finding-based access. A user-friendly personal computer-based software package that allows radiologists to conduct sophisticated real-time searches of diagnostic reports on the basis of patient characteristics, modality used, anatomy examined, and imaging findings and to easily review, refine, and output the results was designed and implemented in a large academic hospital. A notable feature of this system is the use of synonym-matching and syntactic cues, which allow it to identify findings within the text of a diagnostic report much more accurately than a simple keyword search can. This type of system is easily and inexpensively implemented and is a valuable tool in the support of various research and teaching applications in a radiology department.

Radiology Information Systems↗

PubMed1996

Physical map and cosmid contig encompassing a new interstitial deletion of the X-linked lymphoproliferative syndrome region.

The X-linked lymphoproliferative syndrome (XLP) is an inherited immuno-deficiency to Epstein-Barr virus infection that has been mapped to chromosome Xq25. Molecular analysis of XLP patients from ten different families identified a small interstitial constitutional deletion in 1 patient (XLP-D). This deletion, initially defined by a single marker, DF83, known to map to interval Xq24-q26.1, is nested within a previously reported and much larger deletion in another XLP patient (XLP-739). A cosmid minilibrary was constructed from a single mega-YAC and used to establish a contig encompassing the whole XLP-D deletion and a portion of the XLP-739 deletion. Based on this contig, the size of the XLP-D deletion can be estimated at 130 kb. The identification of this minimal deletion, within which at least a portion of the XLP gene is likely to reside, should greatly facilitate efforts in isolating the gene.

Adolescent↗

PubMed1996

Prevalence and parental origin of de novo RET mutations in Hirschsprung's disease.

In contrast with the reported almost exclusive paternal origin of de novo mutations in MEN 2A, FMTC and MEN 2B, de novo mutations in Hirschsprung patients arise both on paternal and maternal chromosomes. This distinctive feature of RET mutations associated with Hirschsprung's disease and of the RET mutations associated with thyroid cancer indicates a basic biological difference between the mutational events leading to the different phenotypes.

DNA Mutational Analysis↗

PubMed1995

The physical map of the human RET proto-oncogene.

The RET proto-oncogene, a transmembrane tyrosine kinase receptor, is involved in the development of at least five different disease phenotypes. RET is activated through somatic rearrangements in a number of cases of papillary thyroid carcinoma while germ-line point mutations are associated with three inherited cancer syndromes MEN 2A, MEN 2B and FMTC. Moreover, point mutations or heterozygous deletions of RET are found in the dominant form of Hirschsprung disease or congenital colonic aganglionosis. We cloned the entire RET genomic sequence in a contig of cosmids encompassing 150 kb, from the CA repeat sTCL-2 to the region upstream the RET promoter, and established the position of the 20 exons of the RET gene with respect to a detailed restriction map based on eight endonucleases. A new highly polymorphic CA repeat sequence was identified within intron 5 of RET (RET-INT5). Finally the orientation of RET on chromosome 10q11.2 made it possible to orientate three other genes rearranged with RET in papillary thyroid carcinomas, namely H4/D10S170 on 10q21, R1 alpha on 17q23 and RFG2/Ele1 on 10q11.2.

Animals↗