Search PubMed⌕ Search

Biomedical subjects

N Li

Publications and source records attributed to N Li.

426 records · Page 24Linked to original sources
PubMed1985

Histopathological and ultrastructural change in liver tissue from burned patients.

Histopathological studies were made on samples of liver and spleen tissue taken post mortem from 59 patients with severe burns. Samples from 8 patients were also studied using the transmission electron microscope. The main pathological findings were degeneration and necrosis of hepatic cells and proliferation of Kupffer cells showing active phagocytosis. Their causes in relation to the time of death after burning and severity of injury have been discussed. The proliferation of Kupffer cells may be a compensatory reaction to the severe splenic injury seen in the patients.

Adolescent↗
PubMed1984

Identification of a new glutathione S-transferase from rat liver cytosol.

A new glutathione S-transferase has been purified to homogeneity from 105,000 X g supernatant of Sprague-Dawley rat liver homogenates. The purified enzyme exhibited specific activities of approximately 1.8, and 0.12 mumoles X min-1 X mg-1 toward 1-chloro 2,4-dinitrobenzene and cumene hydroperoxide respectively. The SDS gel electrophoresis data on subunit composition revealed that the new transferase is composed of two subunits with an identical Mr of 24,400 (Y alpha Family). Our in vitro translation experiments with rat liver poly(A) RNAs and substrate specificity data suggest that this subunit is different from the previously reported Ya , Yb and Yc subunits of rat liver glutathione S-transferases. Comparatively, the new isozyme showed significant activity toward 1,2 epoxy-3-(P-nitrophenoxy)-propane, ethacrynic acid and P-nitrophenyl acetate, 0.4, 0.34 and 0.18 mumoles. min-1 X mg-1 respectively.

Animals↗
PubMed1984

The nucleotide sequence of a rat liver glutathione S-transferase subunit cDNA clone.

We have determined the nucleotide sequence of a cloned cDNA derived from liver poly(A) RNA of pentobarbital-treated rats encoding a glutathione S-transferase subunit. This cDNA clone pGTR261 contains one open reading frame of 222 amino acids, a complete 3' noncoding region, and 63 nucleotides in the 5' noncoding region. The cloned DNA hybridizes to rat poly(A) RNA in a tissue-specific fashion, with strong signals to liver and kidney poly(A) RNA(s) of approximately 1100 and approximately 1400 nucleotides in size but little or no hybridization to poly(A) RNAs from heart, lung, seminal vesicles, spleen, or testis under stringent conditions. Our sequence covers the cDNA sequence of pGST94 which contains a partial coding sequence for a liver glutathione S-transferase subunit of Ya size. Comparison of sequences with our earlier clone pGTR112 suggests that there are at least two mRNA species coding for two different subunits of the Ya (Mr = 25,600) subunit family with very limited amino acid substitutions mainly of conserved polarity. The divergent 3' noncoding sequences should be useful molecular probes in differentiating these two different but otherwise very similar subunits in induction and genomic structure analyses. Our results suggest that tissue-specific expression of the glutathione S-transferase subunits represented by the sequences of pGTR261 and pGTR112 may occur at or prior to the level of RNA processing.

Amino Acid Sequence↗
PubMed1984

Human chromosome hot points. 1. Hot point at 3p14 in three populations.

A chromosome hot point, 3p14, in healthy peasants, mentally retarded patients (MR), and epileptic patients (EP) was studied. The frequency of the hot point, 3p14 break, was significantly higher in EP. It may be caused by folic acid reduction in patients' serum induced by the antiepileptic drugs. The difference between hot point and fragile site is discussed.

Adolescent↗
PubMed1983

Effect of intravenous infusion on development of pulmonary oedema after inhalation injury.

Last year, after a systematic search of pathological and patho-physiological changes of inhalation injury in dogs, we recorded severe pulmonary oedema as early as 2 h postburn (the earliest monitoring time designed in experiment) on dogs inflicted with both body surface and severe respiratory burns without any fluid replacement during the whole course of experiment. In an analysis of cases admitted into our burn centre in the past ten years, we also found that there was no definite relationship between the incidence and severity of pulmonary oedema occurring in severe burn patients and the amount of fluid infused in the early burn phase. These facts led us to the following experiment designed to study the effect of intravenous infusion on development of pulmonary oedema after severe burns complicated with inhalation injuries.

Animals↗
PubMedDate not supplied

A comparative study of determinants of uxorilocal marriage in two counties of China.

A strictly maintained patrilineal family system makes virilocal marriage almost universal and uxorilocal marriage rare in the history of rural China. Uxorilocal marriage can be divided into two types that may be termed, respectively, contingent and institutional. The former preserves family lineages in families without a son and occurs when uxorilocal marriage is uncommon. The latter serves practical economic purposes in families with sons and occurs when uxorilocal marriage is relatively prevalent. Using data from a survey in two counties of Shaanxi--Lueyang, where both kinds of uxorilocal marriage are prevalent, and Sanyuan, where uxorilocal marriage is rare and usually contingent--this paper employs logistic regression models in a quantitative comparative study of determinants of uxorilocal marriage in rural China. We show that the purposes and prevalence of the two types of uxorilocal marriage differ and that their determinants are also different in the two counties. In Sanyuan, the determinants are only a couple's sibling composition, membership in a large family clan, and educational level. In Lueyang, in addition to those determinants in Sanyuan, important contributions to the type of uxorilocal marriage include a couple's parental marriage type, age at marriage, adoption status, marriage arrangement, and their attitudes toward uxorilocal marriage. The results indicate the potential importance of encouraging uxorilocal marriage in rural areas as a means of mitigating demographic and social problems related to son preference, such as high sex ratio at birth and lack of old-age security, which are projected for China's future.

Adolescent↗
PubMedDate not supplied

Proliferative effect of mevalonate metabolites other than isoprenoids on cultured vascular smooth muscle cells.

1. Recent investigations revealed that isoprenoid compounds serve as key substances for cellular proliferation through post-translational modification. Previously we reported that tissues of spontaneously hypertensive rats (SHR) had a lower activity of isoprenoid biosynthesis when compared with the normotensive control rat (WKY). However, cultured vascular smooth muscle cells (VSMC) of SHR showed an enhanced growth rate. These findings led us to investigate further the effect of isoprenoid compounds on VSMC proliferation. 2. When the cells of WKY were stimulated with 5% fetal calf serum (FCS) in the presence of lovastatin, [3H]-thymidine incorporation decreased in a dose-dependent manner and was completely inhibited at 30 mumol/L. Exogenously added mevalonate showed a protective effect against lovastatin (81% protection at 0.1 mumol/L). 3. Fluoromevalonate (Fmev), an inhibitor of mevalonate-PP decarboxylase which converts mevalonate-PP into isoprenoids, showed a dual inhibitory effect. DNA synthesis was partially inhibited at 0.01-1 mumol/L, however at 10 mumol/L there was no detectable inhibition. The inhibitory effect was again observed at concentrations over 10 mumol/L. 4. In the presence of lovastatin and Fmev to block both HMG CoA reductase and mevalonate-PP decarboxylase, exogenous mevalonate dose dependently stimulated [3H]-thymidine incorporation induced by FCS. 5. These data suggest the positive effect of the initial mevalonate derivatives other than isoprenoid compounds on the proliferation of VSMC.

Animals↗
PubMedDate not supplied

BRCA1 germline mutations in Chinese patients with hereditary breast and ovarian cancer.

The role of germline BRCA1 mutations in hereditary breast and ovarian cancer (HBOC) has been well established in women in Western countries. However, relatively few studies have been carried out in Chinese population. In the present study, we investigated the frequency and spectrum of germline BRCA1 mutations in Chinese HBOC patients, all of whom were from northern part of China. A total of 25 women with HBOC and ten relatives were analyzed. Mutation screening was performed by a combination of denaturing high-performance liquid chromatography and sequencing. Seven protein-truncating mutations were identified. They were 667delG, 3347A --> T, 3478del5, 4255delCT, 1235A --> G, 2064G --> T, and 5589del8. The first four of the mutations were putative ones never reported before. The prevalence of the protein-truncating mutations in this HBOC series was 40.0%, which is similar to that observed in Western hereditary ovarian cancer patients but higher than that reported in Chinese women with sporadic breast and ovarian cancer. Among the ten relatives we analyzed, six shared the same mutations with their affected relatives. No ovarian cancer was detected after 19 months of follow-up. This study showed that BRCA1 mutations play an important role in Northern Chinese HBOC.

Adult↗
PubMedDate not supplied

Predicting survival of patients with sepsis by use of regression and neural network models.

OBJECTIVES: (1) To predict at the time of diagnosis of sepsis the subsequent occurrence of multiple organ failure and patient death; and (2) to compare the prediction accuracies of standard multiple logistic regression (MLR) and neural network (NN) models. METHODS: The data were collected during a 5-year period for all patients (n=173) who met prospectively determined criteria for sepsis and had positive blood culture results while admitted in the surgical intensive care unit at the University Hospital of Geneva, Switzerland. These data formed the basis for a retrospective cohort study described elsewhere. The MLR model was adapted from existing data. An NN model of the feed-forward, back-propagation type was constructed for predicting the outcome of sepsis with bloodstream infection. Both models were constructed from randomly chosen subsets of patients and subsequently were evaluated on the remaining (independent) patients. RESULTS: Survival after sepsis was predicted with an accuracy of 80% by the NN model, which used only information collected at the time of the diagnosis of sepsis. The development of multiple organ failure after the diagnosis of sepsis was predicted accurately (81.5%) with either the MLR or the NN model. Both the MLR and the NN methods depended on the interpretation of a likelihood quantity, requiring the choice of a threshold to make a survival prediction. The accuracy of the MLR models was very sensitive to the threshold value. The accuracy of the NN models was not sensitive to the choice of threshold, because they generated likelihood predictions that were distributed far from the middle range where the threshold was placed. CONCLUSION: Compared with MLR models, the NN models were slightly more accurate and much less sensitive to the arbitrary threshold parameter.

Bacterial Infections↗