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Biomedical subjects

X L Wen

Publications and source records attributed to X L Wen.

18 recordsLinked to original sources
PubMed2001

[Effect of simulated weightlessness on the apoptosis of thymus cells in tail-suspended mice].

OBJECTIVE: To investigate the effect of simulated weightlessness on apoptosis of thymus cells in mice. METHOD: Tail-suspended mice were used as an animal model of simulated weightlessness; chromosome breakage was measured by PI staining, and changes of cell membrane were determined by Annexin-V analysis. RESULT: As compared with the control, there was no obvious chromosome breakage; the total number of apoptotic cells and number of early apoptotic cells increased in 1 d suspended group; the number of early apoptotic cells increased significantly and the total number of apoptotic cells increased very significantly in 2d suspended groups. CONCLUSION: These results suggested that simulated weightlessness could promote apoptosis of thymus cells.

Animals↗
PubMed2001

[Effects of simulated weightlessness on T cell subpopulations and activity of IL-2 and IL-6 in mice].

OBJECTIVE: To observe the effects of simulated weightlessness on the immunogenic activities in mice. METHOD: T cell subpopulations and the activity of IL-2 and IL-6 were observed in mice after exposure to head-down (-30 degrees) tail suspension for 3 d and 7 d. RESULT: The activity of IL-2 and IL-6 in mice showed no change after simulated weightlessness for 3 d compared with the control group. But after simulated weightlessness for 7 d, CD3+ and CD4+ were markedly reduced (both P< 0.01) and CD8+ and CD4+/CD8+ also tended to decrease; the activity of IL-2 was significantly decreased, while the activity of IL-6 tended to increase. CONCLUSION: Simulated weightlessness for 7 d had significant effects on T cell subpopulations and the activity of certain cytokines in mice.

Animals↗
PubMed2001

[Protective effects of Chinese herb-compound on cellular immunological function (correction of funcion) in tail-suspended rats].

Objective. To observe the protective effects of two kinds of Chinese herb-compounds (Dan-huang-ci compound and Shen-chuan-shu compound) on cellular immunology in tail-suspended rats. Method. The rats were divided into: 1) normal control group; 2) tail-suspended group; 3) tail-suspended + Dan-huang-ci compound; and 4) tail-suspended + Shen-chuan-shu compound. Ability of lymphocyte proliferation and production of IL-2 in rats in the four groups were compared after 21 d. Result. The immunological function of tail-suspended control group decreased significantly as compared with normal control group. Shen-chuan-shu compound could improve immunological function of tail-suspended rats obviously. Conclusion. Shen-chuan-shu compound could enhance cellular immunological function in rats under simulated weightlessness.

Animals↗
PubMed1999

[Effect of -6 degrees head-down-bed-rest on human cellular immune function].

OBJECTIVE: To observe the effect of -6 degrees head-down bed-rest on proliferation of lymphocyte and production of certain cytokines. METHODS: 6 healthy young men served as the subjects. Peripheral blood lymphocyte was assayed 1d prior to and on the 3rd day and 6th day of bed rest. RESULTS: The production of IFN-alpha on the 3rd day was markedly decreased (P < 0.05), but killing activity of NK was significantly enhanced (P < 0.05), production of IFN-gamma and expression of IL-2 receptor were all slightly reduced. Both production of IFN-alpha and killing activity of NK resumed to the control level on the 6th day, production of IFN-r and CD25 were significantly lowered (P < 0.05) on the 6th day, a lymphocyte proliferation and production of IL-2 were gradually decreased with time, but production of IL-6 was gradually increased. CONCLUSION: -6 degrees head-down bed-rested has certain effect on cellular immune function in man.

Adult↗
PubMed1999

[The effect of simulated weightlessness on the function of spleen lymphocytes and the expression of c-fos proto-oncogene in tail-suspended mice].

Objective. To investigate the effect of simulated weightlessness on proliferation of spleen lymphocyte, production of interleukin-2 and expression of c-fos proto-oncogene in mice. Method. Mice were tail-suspended for 7 or 14 days to simulate the effect of weightlessness; proliferation of lymphocyte was measured by MTT method, production of IL-2 was determined by biological activity and expression of c-fos proto-oncogene was determined by dot blotting. Result. As compared with the control, the proliferation of spleen lymphocyte and the production of IL-2 were significantly decreased in 14 d suspended group, but the expression of c-fos proto-oncogene [correction of oncogen] was increased in both 7 d and 14 d suspended groups. Conclusion. This result suggested that simulated weightlessness could interfere with the genes regulating the lymphocyte.

Animals↗
PubMed1998

GABAergic cells and signals in CNS development.

GABA is formed primarily from decarboxylation of glutamate by a family of cytosolic and membrane-bound GAD enzymes. In the adult, GAD-derived GABA sustains the vitality of the central nervous system (CNS), since blockage of GAD rapidly leads to convulsions and death. In plants, cytosolic GAD synthesizes GABA in response to hormones and environmental stress. Since decarboxylation involves protonation, secretion of GABA serves to buffer cytosolic pH in plant cells. Families of GAD and GABAA receptor/Cl- channel transcripts and encoded proteins emerge early and seemingly everywhere during CNS development, with their abundance closely paralleling neurogenesis and peaking before birth. Micromolar GABA acts at receptor/Cl-channels to depolarize progenitor cells in the cortical neuroepithelium; it also elevates their cytosolic Ca2+ (Cac2+) levels. In some way, these effects decrease proliferation. GABA directs the migration of postmitotic neuroblasts at femtomolar concentrations and stimulates their random motility at micromolar concentrations via Ca2+ signaling mechanisms. Activation of GABAA receptors by micromolar GABA may limit motility via membrane depolarization and elevated Cac2+. These results indicate that in vitro GABA can affect embryogenesis of the CNS through effects on cell proliferation and migration. As neurons differentiate postnatally, Cl(-)-dependent depolarization disappears together with GABAergic Cac2+ signals. Physiologically occurring GABAergic signals at Cl-channels exist in tonic and transient forms. Since the former are found on progenitor cells while both are present in postmitotic neurons, mechanisms to generate transients differentiate in the latter. Surprisingly, tonic and transient forms of GABAergic signaling at Cl-channels are rapidly and smoothly interconvertible and seem to be derived from online GABA synthesis in a surface-accessible compartment of the membrane.

Animals↗
PubMed1996

Human herpesvirus type 8 DNA sequences in cell-free plasma and mononuclear cells of Kaposi's sarcoma patients.

Human herpesvirus (HHV) type 8 has been detected in both classical and AIDS-related Kaposi's sarcoma, body-cavity lymphomas, and other types of tumors. HHV-8 has also been detected in DNA from peripheral blood mononuclear cells (PBMC) of some Kaposi's sarcoma patients and more readily in B cell fractions derived from panned cell subpopulations. Two patients were followed using several methods; in situ hybridization, solution-based polymerase chain reaction (PCR), and in situ PCR. HHV-8 was intermittently detected in plasma, and detection correlated with detection in PBMC. In situ PCR demonstrated HHV-8 sequences in both peripheral blood B lymphocytes and, to a lesser extent, T lymphocytes. HHV-8 may undergo periods of viremia while at other times it is undetectable and infects circulating B cells and some T cells.

Adult↗
PubMed1993

Classification of pulse waveform of cerebral spinal fluid during intracranial pressure monitoring.

Cerebral spinal fluid (CSF) pulse waveform basing on 899 records was classified. Eleven types of CSF pulse waveform were further classified according to the harmonic wave relation and the configuration of the pulse waveform. The characteristic features of various types of CSF pulse waveform were considered to reflect certain intracranial pathophysiological conditions including cerebral compliance, cerebral vasomotor reactivity and intracranial elastance.

Brain Injuries↗
PubMed1991

The use of corticotropin releasing factor (CRE) for the treatment of post-operative cerebral edema. A preliminary study.

Synthetic corticotropin-releasing factor (CRF) was administered pre-operatively to five patients who underwent craniotomy for brain tumors, acute subdural and intracerebral hematomas. After craniotomy, an intraventricular catheter is placed in the ventricle, on the normal side of brain. This is for intracranial pressure monitoring. The data obtained were pooled and compared with the saline group (n = 6). The CRF group was found to have statistically significant difference (P less than 0.01). This preliminary study showed that CRF decreases postoperative edema.

Adult↗
PubMed1990

Medicinal protection with Chinese herb-compound against radiation damage.

Experiments were carried out on mice and the subjects irradiated for cancer therapy to evaluate the protective efficacy of a Chinese medicinal herb-compound (CMHC). The lethality and the degree of leucopenia caused by radiation in mice medicated with CMHC were significantly less in comparison with control mice (p less than 0.01 and p less than 0.001, respectively). CMHC significantly improved the WBC and the thrombocytes in irradiated workers (p less than 0.01 and p less than 0.001, respectively). The WBC count of 40 patients under radiotherapy while treated with CMHC recovered from 3450 +/- 77/c.mm to 5425 +/- 264/c.mm (p less than 0.001); whereas, in the control group, without any medication, the WBC count dropped significantly (p less than 0.001). Our results revealed the applicabilities of CMHC in protection against radiation damage in spaceflight and in other fields.

Animals↗
PubMed1986

Induction of heavy metal binding groups by dexamethasone and Zn in cultured Chinese hamster ovary cells.

Cd binding capacity and pulse polarography were used to study the inducibility of sulfhydryl groups in cultured Chinese hamster ovary cells (wild type and a Cd-resistant mutant) in response to dexamethasone (dex) and Zn. Evidence is presented that both the wild type and the mutant responded to dex and Zn treatment by induction of sulfhydryl groups. In wild type for Zn and dex as well as in the mutant for dex, this induction seems to be in the form of sulfhydryls attached to particulate or membrane fractions in the cells. For Zn in the Cd-resistant mutant the induction was in the form of metallothionein.

Animals↗
PubMed1985

Effects of adrenocorticotropic hormone, human chorionic gonadotropin, and insulin on steroid production by human adrenocortical carcinoma cells in culture.

Adrenocortical carcinoma tissue removed from a mildly hirsute 16-year-old girl was cultured in order to assess steroidogenesis and responsiveness of the cells to adrenocorticotropic hormone (ACTH), human chorionic gonadotropin (HCG), and insulin. The cells in culture produced large amounts of androstenedione and testosterone; however, production of cortisol, which was initially high, decreased with time. No aldosterone, estrone, or estradiol was produced in vitro. Both monolayer cells maintained for 6 weeks and organ culture explants maintained for over 3 days responded to ACTH (10(-7) M) with increased production of androgens (testosterone, androstenedione, dehydroepiandrosterone) but decreased production of cortisol as measured by radioimmunoassay of steroids in the culture media. Concomitant with decreased cortisol production was the enhanced formation of 11-deoxycortisol in cells exposed to ACTH, suggesting impaired 11 beta-hydroxylation. Tissue exposed to HCG (10(-7) M) in organ culture showed an increase in androgen production over control levels, but no significant effect of HCG on glucocorticoid production was found. Tumor cells differed in their androgen response to ACTH and HCG, with enhanced adrenal androgens in the presence of ACTH and more gonadal-type androgens after exposure to HCG. Insulin exposure had no effect on production of either androgen or glucocorticoid by tumor tissue in organ culture. Thus, this adrenocortical carcinoma showed marked androgen production in culture which was enhanced in different ways by ACTH and HCG. 11 beta-Hydroxylation was impaired with time in culture. No specific effect of insulin on steroidogenesis was noted.

Adolescent↗