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Biomedical subjects

M Ding

Publications and source records attributed to M Ding.

At least 163 records · Page 9Linked to original sources
PubMed1996

[Correlation analysis of the changes of EEG mapping and the changes of CT scan in patients with senile dementia].

OBJECTIVE: To observe the changes of EEG mapping and CT scan and analyse the correlation between the changes of the function presented by EEG mapping and morphology presented by CT. METHODS: The absolute power of EEG mapping and 9 parameters of CT in 30 normal controls and 31 patients with senile dementia were measured. The correlation was analysed quantitatively with multiple stepwise regression method. RESULTS: The EEG mapping of senile dementia revealed a diffuse increase in delta, theta power and decreased alpha power in most areas. CT scan showed cortical and subcortical atrophy in brain. There were positive correlations between the increase of delta power and lateral fissure, and between the increase of delta power and average cerebral sulcus. There was a negative correlation between the decrease of alpha power and the increase of lateral fissure. CONCLUSION: The EEG mapping and CT in patients with senile dementia are different from those in normal elderly. There is a correlation between the changes of EEG mapping and CT scan.

Aged↗
PubMed1996

[An alpha-1-antitrypsin deficiency allele PI*Siiyama found in a disputed paternity case].

An incompatible mother-child pair was found in an alpha-1-antitrypsin (PI) system in a disputed paternity case. By the isoelectric focusing, the PI type of the mother and the child were confirmed PI M1 and PI M2, respectively. Testing of many other genetic markers could not exclude her motherhood. Therefore, the mother and the child were inferred to be heterozygous carriers of a PI deficiency allele. PCR-SSCP analysis of exon 2 suggested that the PI types of the mother and the child are heterozygous M1-Siiyama and M2-Siiyama, respectively.

Alleles↗
PubMed1995

Tumor necrosis factor-alpha induces substance P in sympathetic ganglia through sequential induction of interleukin-1 and leukemia inhibitory factor.

The present study establishes that tumor necrosis factor-alpha (TNF-alpha) induction of sympathetic substance P (SP) requires sequential induction of both interleukin (IL-1) and leukemia inhibitory factor (LIF). TNF-alpha dose-dependently induces SP, an induction that is secondary to an increase in the SP precursor, preprotachykinin (PPT), mRNA. Since TNF-alpha conditioned medium (CM) mimics the effect of TNF-alpha by raising SP, actions that are not antagonized by a neutralizing TNF-alpha antibody, TNF-alpha induction of SP is mediated by a soluble intermediate or intermediates. The blockade of TNF-alpha action by a specific IL-1 receptor antagonist and the induction of IL-1 mRNA by TNF-alpha suggest that IL-1 is one of the intermediates. Moreover, because immunoprecipitation with LIF antibodies decreases SP-inducing activity of TNF-alpha CM, and because LIF mRNA is also induced by TNF-alpha, LIF is a second intermediate. Furthermore, TNF-alpha-induced LIF mRNA is blocked by the IL-1 receptor antagonist, whereas IL-1-induced LIF mRNA is not affected by TNF-alpha antibodies, suggesting that TNF-alpha first induces IL-1, and IL-1 subsequently induces LIF. These data suggest that TNF-alpha induces SP in sympathetic ganglia through the sequential inductions of IL-1 and LIF.

Animals↗
PubMed1995

Molecular basis of inter-alpha-trypsin inhibitor heavy chain H1 (ITIH1) polymorphism.

A genetic polymorphism of the inter-alpha-trypsin inhibitor heavy chain H1 (ITIH1) was analyzed at the nucleic acid level. Three common alleles, ITIH1*1, ITIH1*2 and ITIH1*3, were characterized by mutations at codons 551 and 561 in exon 14. ITIH1*1 was characterized by GAG (Glu) at codon 551 and CAG (Gln) at codon 561, ITIH1*2, by GTG (Val) and CGG (Arg), and ITIH1*3, by GAG (Glu) and CGG (Arg).

Alpha-Globulins↗
PubMed1995

Copresence of prostaglandin EP2 and EP3 receptors on gastric enterochromaffin-like cell carcinoid in African rodents.

BACKGROUND & AIMS: Prostaglandins (PGs) have important roles in the regulation of gastric acid secretion. The aim of this study was to examine the possible presence of PG receptors on the gastric enterochromaffin-like (ECL) carcinoid of Mastomys natalensis, which might be a useful model of normal ECL cells. METHODS: A [3H]PGE2 binding experiment was performed by using the ECL tumor membrane, and intracellular signal transduction was studied in the cells. In addition, Northern blot analysis using EP2 and EP3 receptor complementary DNAs was conducted. RESULTS: [3H]PGE2 specifically bound to the tumor cell membrane, and the binding was displaced by various PGs with a potency order of PGE1 = PGE2 > enprostil > PGF2 alpha. Although PGE1 and PGE2 stimulated 5'-cyclic adenosine monophosphate (cAMP) production, neither PGF2 alpha nor enprostil had any effect. On the other hand, all of PGE1, PGE2, PGF2 alpha, and enprostil attenuated the forskolin-induced cAMP production. Moreover, enprostil inhibited histamine release induced by forskolin. However, on pertussis toxin treatment, PGE2 paradoxically enhanced the forskolin-induced increase of cAMP production. Finally, the presence of EP2 and EP3 receptor messenger RNAs was confirmed by RNA blot analysis. CONCLUSIONS: The ECL carcinoid tumor cells of Mastomys seem to possess two subtypes of PGE receptor: EP2 linked to cAMP production and EP3 coupled with inhibitory guanosine 5'-triphosphate-binding proteins mediating the inhibition of cAMP production.

Animals↗
PubMed1995

Intermittent aortic crossclamping prevents cumulative adenosine triphosphate depletion, ventricular fibrillation, and dysfunction (stunning): is it preconditioning?

This study was designed to determine whether intermittent warm aortic crossclamping induces cumulative myocardial stunning or if the myocardium becomes preconditioned after the first episode of ischemia in canine models in vivo. The role of adenosine triphosphate catabolism and subsequent release of purines on reperfusion-mediated postischemic ventricular dysfunction and arrhythmias was assessed with the use of selective inhibitors of nucleoside transport, p-nitrobenzylthioinosine (NBMPR), and a specific adenosine deaminase inhibitor, erythro-9-[2-hydroxy-3-nonyl] adenine (EHNA). Thirty-two anesthetized dogs were instrumented to monitor left ventricular contractility, off bypass, by sonomicrometry. During cardiopulmonary bypass dogs were treated before ischemia with either saline solution (control group, n = 8) or EHNA (100 mumol/L) and NBMPR (25 mumol/L) (EHNA/NBMPR group, n = 8). Hearts were subjected to either 60 minutes of global ischemia and 120 minutes of reperfusion (n = 16) or 6 episodes of 10 minutes of global ischemia and 10 minutes of reperfusion, followed by 60 minutes of reperfusion (n = 16). Sixty minutes of sustained ischemia resulted in 80% loss of adenosine triphosphate and induced reperfusion-mediated ventricular fibrillation and severe left ventricular dysfunction in the control group. EHNA/NBMPR treatment augmented myocardial adenosine trapping during ischemia, attenuated ventricular fibrillation, and enhanced left ventricular functional recovery, despite similar depletion of adenosine triphosphate (80% loss). In the intermittent ischemia experiment, the first episode of 10 minutes of ischemia and reperfusion caused significant adenosine triphosphate depletion, ventricular fibrillation, and left ventricular stunning in both control and drug-treated groups. The prevalence of ventricular fibrillation was greater in the control group than in the drug-treated group after the first episode of ischemia (p < 0.05). Adenosine was the major nucleoside accumulated in the myocardium at the end of 10 minutes of ischemia in the EHNA/NBMPR-treated group (p < 0.05 versus control). Subsequent episodes of ischemia prevented ventricular fibrillation and did not cause cumulative left ventricular stunning in either group. Left ventricular function fully recovered in the EHNA/NBMPR-treated group after intermittent ischemia, but remained stunned in the control group. Unlike sustained ischemia, intermittent ischemia and reperfusion preserved myocardial adenosine triphosphate, limited purine release, and prevented ventricular fibrillation and cumulative stunning. These results suggest that intermittent ischemia and reperfusion augmented the endogenous protective mechanism or mechanisms of "preconditioning." Nucleoside trapping improved functional recovery after sustained or repetitive ischemia. It is concluded that adenosine triphosphate preservation or blockade of nucleoside transport may play an important role in the activation of endogenous myocardial protective mechanisms that "precondition" against subsequent ischemic stress.

Adenine↗
PubMed1995

Quantitation of human immunodeficiency virus type 1 DNA and RNA by a novel internally controlled PCR assay.

A novel internally controlled PCR (ICPCR) assay was developed to accurately quantitate human immunodeficiency virus type 1 (HIV-1) DNA and RNA in peripheral blood mononuclear cells and plasma. The ICPCR assay was sensitive and reproducible within a linear range of amplification of 10(0) to 10(3) copies for HIV-1 DNA and 10(1) to 10(4) copies for HIV-1 RNA. The assay detected HIV-1 RNA in plasma and peripheral blood mononuclear cells from all HIV-1 subjects regardless of disease stage. ICPCR was compared with a branched-DNA signal amplification assay for subjects beginning antiretroviral therapy. The reductions in plasma HIV-1 RNA in response to therapy were comparable with the two assays. The ICPCR assay should be useful in monitoring HIV-1 RNA levels both in natural history studies and in clinical trials of antiretroviral agents.

DNA, Viral↗
PubMed1995

High levels of anti-human immunodeficiency virus type 1 (HIV-1) memory cytotoxic T-lymphocyte activity and low viral load are associated with lack of disease in HIV-1-infected long-term nonprogressors.

Lack of disease in long-term nonprogressors with human immunodeficiency virus type 1 (HIV-1) infection was strongly associated with very low copy numbers of HIV-1 DNA and RNA in peripheral blood mononuclear cells and plasma and the presence of high levels of anti-HIV-1 CD8+ memory cytotoxic T lymphocytes specific for Gag, Pol, and Env, compared with levels present in intermediate and advanced progressors. CD8+ memory cytotoxic T lymphocytes may have an important role in controlling HIV-1 replication and preventing disease in long-term nonprogressors.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Evaluation of a dynamical model of speech perception.

Previous work (Tuller, Case, Ding, & Kelso, 1994) has revealed signature properties of nonlinear dynamical systems in how people categorize speech sounds. The data were modeled by using a two-well potential function that deformed with stimulus properties and was sensitive to context. Here we evaluate one prediction of the model--namely, that the rate of change of the potential's slope should increase when the category is repeatedly perceived. Judged goodness of category membership was used as an index of the slope of the potential. Stimuli from a "say"-"stay" continuum were presented with gap duration changing sequentially throughout the range from 0 to 76 to 0 msec, or from 76 to 0 to 76 msec. Subjects identified each token as either "say" or "stay" and rated how good an exemplar it was of the identified category. As predicted, the same physical stimulus presented at the end of a sequence was judged a better exemplar of the category than was the identical stimulus presented at the beginning of the sequence. In contrast, stimuli presented twice near the middle of a sequence with few (or no) stimuli between them, as well as stimuli presented with an intervening random set, showed no such differences. These results confirm the hypothesis of a context-sensitive dynamical representation underlying speech.

Humans↗
PubMed1995

[The distribution of SbV nonstructural protein 2 (nsP2) in host cell].

The distribution of SbV nsP2 has been observed by means of immunolabelling electron microscopy. The results showed that SbV nsP2 existed both in the cytoplasm and in the nucleus of host cell. When the cDNA of SbV nsP2 was transfected in host cell, the nsP2 also accumulates in the nucleus.

Cell Nucleus↗
PubMed1995

The microtubule cytoskeleton in human phagocytic leukocytes is a highly dynamic structure.

The microtubule cytoskeleton of human leukocytes has been difficult to study, in part, due to the lack of a reliable protocol for the indirect immunofluorescence staining of microtubules in these cells. We report here the development of a simple and reliable immunocytochemical labeling protocol for the examination of microtubules in leukocytes including monocytes, neutrophils, and eosinophils. The dynamic properties of microtubules in both monocytes and neutrophils were examined by indirect immunofluorescence staining of cells following exposure to nocodazole. Nocodazole-induced depolymerization is extremely rapid in both cell types, as is the regrowth of microtubules following removal of the nocodazole. Rapid reorganization of the microtubule cytoskeleton was also observed in neutrophils undergoing chemotactic stimulation. Bundling of microtubules was observed in both monocytes and neutrophils isolated from patients undergoing taxol infusion chemotherapy. The taxol-induced bundles were transient in nature as they were absent from samples collected 48 h following the completion of the taxol infusion. These results demonstrate the unique dynamic properties of leukocyte microtubules and indicate that they can be altered in vivo. The development of this staining protocol should allow for the further analysis of leukocyte microtubules as related to the normal functional response of these cells and form the basis for correlating alterations in microtubule dynamics with the effects of taxol on leukocyte function.

Drug-Related Side Effects and Adverse Reactions↗
PubMed1995

[The preliminary study of insulin resistance in pregnancy induced hypertension].

OBJECTIVE: To observe the changes of glucose metabolism in late pregnancy and to reveal the relationship between insulin resistance and pregnancy induced hypertension (PIH). METHODS: The 75g oral glucose tolerance test (OGTT) was performed in 30 cases with PIH (37-41 weeks gestation), 30 cases of normal pregnancy and 12 non-pregnant women. The levels of serum glucose, insulin and C-peptide were measured by radioimmunoassay, and the areas under the curve (AUC) were calculated. RESULTS: There were significant increases of the peak level or AUC of insulin in PIH (61.42 +/- 48.72, 137.12 +/- 81.12 mIU/L) and in normal pregnant group (70.46 +/- 58.42, 150.37 +/- 104.76 mIU/L) compared with non-pregnant controls (17.12 +/- 11.03, 34.38 +/- 16.01 mIU/L) (P < 0.01), however, they had a similar glucose levels before or after GTT (P > 0.05). Furthermore, there was no correlationship between systolic or diastolic blood pressure and the fasting insulin or the AUC. CONCLUSIONS: Insulin resistance and hyperinsulinemia were found in late pregnancy, but the changes of insulin resistance in PIH cases was not significant. So, there was no definitive relationship between insulin resistance and the rising of blood bressure of PIH.

Adult↗
PubMed1995

Fibroblast growth factor 2 increases Otx2 expression in precursor cells from mammalian telencephalon.

Dissociated primary cultures from rat telencephalon at different developmental stages were used to study the effect of basic fibroblast growth factor (FGF2) on Otx2, Dlx1, and Emx1, three homeobox genes expressed in different regions of the developing mammalian forebrain. At embryonic day (E)13.5. the regional pattern of expression of Otx1, Otx2, Dlx1, Dlx2, Dlx5, and Emx1 is maintained in primary culture, suggesting that cells are already committed to a regional identity at this stage. In these cultures, Otx2 is expressed by precursor cells, whereas Dlx1 and Emx1 are predominantly expressed by postmitotic cells. We found that FGF2 increased Otx2 expression within precursor cells and the total number of Otx2-expressing cells. This effect was gene-specific, dose-dependent, and temporally regulated, with larger effects at earlier stages of development (E11.5). At E13.5, the effect of FGF2 on Otx2 expression was restricted to the basal telencephalon. Our results suggest that a restricted population of neuroblasts respond to FGF2 in a temporally regulated fashion by proliferating and increasing Otx2 expression. This interaction between FGF2 and Otx2 may be important for the regulation of neurogenesis in the forebrain.

Animals↗