Biomedical subjects

L He

Publications and source records attributed to L He.

At least 271 records · Page 15Linked to original sources

PubMed1998

Dietary soluble fiber lowers plasma LDL cholesterol concentrations by altering lipoprotein metabolism in female guinea pigs.

This experiment was designed to evaluate the effects of pectin (PE), guar gum (GG) and psyllium (PSY) intake on VLDL and LDL metabolism in female guinea pigs fed high dietary cholesterol. Guinea pigs were fed a 15 g/100 g fat diet containing 0.25 g/100 g cholesterol with 12.5 g/100 g PE, 12.5 g/100 g GG, 7.5 g/100 g PSY or 12.5 g/100 g cellulose (control diet) for 4 wk. Plasma cholesterol concentrations were 29, 43 and 39% lower in guinea pigs fed PE, GG or PSY, respectively, compared with the control group (P < 0.0001). Plasma apolipoprotein (apo) B concentrations were 16-22% lower in the groups fed soluble fiber compared with the control group (P < 0.01). In contrast, hepatic cholesterol and triglyceride concentrations were not different among the PE, GG, PSY and control groups. No differences in triacylglycerol (TAG) or apo B secretion rates, measured by blocking VLDL catabolism by triton (WR 1339) injection, were observed, whereas plasma LDL apo B fractional catabolic rates (FCR), determined by injection of radiolabeled LDL, were higher in guinea pigs fed GG or PSY than in those from the control group. All sources of dietary soluble fiber reduced LDL apo B flux (P < 0.05). These results suggest that the mechanisms of plasma LDL cholesterol lowering by dietary soluble fiber are distinctive for each fiber source and result in specific alterations in lipoprotein metabolism in female guinea pigs. Differences between male and female guinea pigs in response to these diets are discussed.

Animals↗

PubMed1998

Physiological role for the GlnK protein of enteric bacteria: relief of NifL inhibition under nitrogen-limiting conditions.

In Klebsiella pneumoniae, NifA-dependent transcription of nitrogen fixation (nif) genes is inhibited by a flavoprotein, NifL, in the presence of molecular oxygen and/or combined nitrogen. We recently demonstrated that the general nitrogen regulator NtrC is required to relieve NifL inhibition under nitrogen (N)-limiting conditions. We provide evidence that the sole basis for the NtrC requirement is its role as an activator of transcription for glnK, which encodes a PII-like allosteric effector. Relief of NifL inhibition is a unique physiological function for GlnK in that the structurally related GlnB protein of enteric bacteria-apparently a paralogue of GlnK-cannot substitute. Unexpectedly, although covalent modification of GlnK by uridylylation normally occurs under N-limiting conditions, several lines of evidence indicate that uridylylation is not required for relief of NifL inhibition. When GlnK was synthesized constitutively from non-NtrC-dependent promoters, it was able to relieve NifL inhibition in the absence of uridylyltransferase, the product of the glnD gene, and under N excess conditions. Moreover, an altered form of GlnK, GlnKY51N, which cannot be uridylylated due to the absence of the requisite tyrosine, was still able to relieve NifL inhibition.

Bacterial Proteins↗

PubMed1998

[Clinical guidelines for timing of escharectomy and skin grafting during burn shock stage in extensively burned patients].

OBJECTIVE: To provide practical clinical guidelines to doctors who have no hemodynamic monitoring facilities in performing escharectomy during the shock period in extensively burned patients. METHODS: We analyzed our clinical experiences in 60 patients with extensive burn. RESULTS: Puting forward several clinical indexes for timing of escharectomy during burn shock stage: 1. Amount of fluids in the first 24 h postburn 2.6-3.0 ml.kg-1.1% TBSA-1; 2. Output of urine 80-100 ml/h; 3. Mentally fully conscious; 4. Thirst significantly alleviated and there is no nausea and vomiting; 5. Pulse 100/min; 6. Hb < or = 150 g/L; 7. Hct < or = 0.50. CONCLUSION: With the clinical indexes as guidelines, we assume that escharectomy could be performed during burn shock stage with reasonable safety.

Burns↗

PubMed1998

[Influence of escharectomy during burn shock stage upon the changes in endothelin and NO].

OBJECTIVE: To observe influence of escharectomy during and after burn shock stage upon the changes in plasma ET and NO. METHODS: 35% TBSA full-thickness burn was produced in pigs, which were divided into two groups. Group S was a group undergoing escharectomy during burn shock stage at 24 h postburn. Group C was a group receiving escharectomy at 96 h after injury. ET and NO were determined and ET/NO was calculated. RESULTS: The levels of ET and NO were higher after injury than before injury in both groups. The level of ET was lower significantly in group S than in group C from 96 h postburn on. The level of NO was higher in group S than in group C. The ET/NO was lower in group S than in group C from PBH 24 on. CONCLUSION: Escharectomy during burn shock stage was beneficial in reducing injury of endothelial cells, decreasing exudation and edema, decreasing tissue hypoxia and improving microcirculation.

Animals↗

PubMed1998

[Etiology and clinical analysis of epididymal mass].

The etiology and clinical pathological analysis of 147 cases of epididymal mass were presented. The result showed that the most common mass in inflammatory (66%), and the majority was tuberculosis, the next was cystic diseases (30%). However, neoplasm was relatively less and malignant mass was rare. The diagnosis can be established by careful history, physical examination, and BUS. The selective surgery depends on the nature of diseases, the demand of the patients and the effect of conservative therapy.

Adenomatoid Tumor↗

PubMed1998

Experimental study on pathogenicity of precore mutants in Hepadnaviridae.

OBJECTIVE: To study the replicative competency and pathogenicity of precore gene mutants of duck hepatitis B virus (DHBV) in the duck model. METHODS: Three site-directed point mutations in the precore region of cloned DHBV were constructed. Head-to-tail dimers were formed. The three plasmids were named: pEDM1-2 (initiation codon ATG mutated to TTG), pEDM2-2 (an "A" was inserted down stream of codon 12, leading to frame shift in the distal end of precore region), pEDM3-2 (codon 38 was changed from TAT to TAA, leading to a stop codon at the 3'-end). Mutants and wild-type cloned DNA dimers were first separately used to transfect LMH cells (a chicken hepatoma cell line) and viruses were collected from supernatant and used to infect 6 one-day-old ducklings per group. Serum duck hepatitis B surface antigen (DHBsAg) and DHBV DNA were assayed. Six weeks after infection, ducks were killed and liver tissues were studied for histopathological changes. RESULTS: After transfection, pEDM1-2, pEDM2-2 and pEDM3-2 expressed similar level of DHBsAg. Replication of pEDM1-2 and pEDM3-2 was similar to that of the wild type clone, while pEDM2-2 replicated at a significantly decreased level. Infection study employing the supernatant of transfected cells was as follows: pEDM1-2 infected 5/6 ducklings, pEDM2-2 non infected, pEDM3-2 infected 2/6 ducklings, wild type virus infected 6/6 ducklings. Positive serum samples from both pEDM1-2 and pEDM3-2 were at a lower serum DHBV level compared to that of the wild type virus. Pathological changes were more significant in pEDM3-2 infected duck livers, with numerous inflammatory cells in portal tract and infiltration into parenchyma. CONCLUSIONS: Mutations in the initiating codon or generation of a stop codon at the 3'-end of the precore region resulted in decreased replication competency of DHBV, while frame-shift mutation of the precore region, covering the epsilon encapsidation signal abolished the replication of DHBV. When the mutants replicated in hosts, more severe pathological changes were observed in ducks infected with mutant harboring a stop codon at the 3'-end. Data suggest that replicative-competent DHBV precore mutant can be more pathogenic than wild-type DHBV.

Animals↗

PubMed1998

Androgen receptor in primary hepatocellular carcinoma and its clinical significance.

OBJECTIVE: To assess retrospectively the clinical value of androgen receptor (AR) levels in primary hepatocellular carcinoma (HCC) as a prognostic factor of the disease. METHODS: Fresh HCC tissue and the surrounding liver tissue were obtained surgically from 32 patients with HCC, and preserved in liquid nitrogen. The levels of AR in all specimens were determined by radio-ligand binding assay. RESULTS: The median level of AR was 42.8 fmol/mg protein in the cancerous tissue and 48.3 fmol/mg protein in the surrounding non-cancerous liver tissue. The overall survival rate of the patients with AR < 30 fmol/mg protein in either HCC or the non-cancerous liver was significantly higher than that of the patients with AR > or = 30 fmol/mg protein (P < 0.05 and P < 0.01, respectively). The relative risk on prognosis was 3.27 (P < 0.01) for AR level in HCC and 6.06 (P < 0.001) for AR level in the non-cancerous tissue. The main prognostic factors except the tumor size were not different between the group with higher AR level and that with lower AR level in HCC. The AR level in HCC had a positive correlation with the tumor size (r = 0.44, P < 0.05). CONCLUSIONS: AR can be detected in HCC and the AR status might be a prognostic parameter that provides additional predictive information on the survival. Different AR status might define a real difference of biological characteristics between HCCs.

Adult↗

PubMed1998

[Incidence, risk and prognostic factors of pneumonia acquired at intensive care units].

OBJECTIVE: To estimate the incidence of pneumonia acquired in the intensive care unit, and to define risk factors for developing such an event. METHOD: A total of 158 patients were retrospectively analyzed and 108 of them acquied pneumonia at ICU of Zhongshan Hospital (surgical ICU and respiratory ICU) and Huashan Hospital (general ICU) from January 1996 to November 1997. Statistical analysis was made using SPSS, odds ratios and stepwise logistic regression analysis were used to determine the interrelationships between multiple variables. Statistical significance was predetermined to include p values of < 0.05. RESULT: The following five factors were significantly (P < 0.05) associated with HAP: cancer [OR = 6.73, 95% CI = 1.58 to 28.59], treatment with H2-blockers (OR = 5.5742, CI = 1.94 to 15.99), decreased consciousness (OR = 3.30, CI = 1.52 to 7.18), use of urethral catheters (OR = 1.07, CI = 1.01 to 1.13), and mechanical ventilation (OR = 1.05, CI = 1.00 to 1.01). The risk facors for HAP were different among different ICU. The risk of developing pneumonia increased when depressed level of consciousness and mechanical ventilation were present at general ICU. Factors significantly predisposing to HAP were underlying COPD, using H2-blockers and mechanical ventilation at respiratory ICU, and previously lower respiratory tract infection was the risk factor for HAP in surgical ICU. The following factors were associated with a significantly higher fatality rate in HAP patients: depressed level of consciousness (P = 0.02), previously lower respiratory tract infection (P = 0.001), and long-time mechanical ventilation (P = 0.03). CONCLUSION: The risk factors for HAP were different among different ICU, which may be related to the difference of patients with an ultimately or a rapidly fatal underlying illness admitted to these units.

Cross Infection↗

PubMed1998

[Analysis of etiological agents and death-relating factors of pulmonary infections in immunocompromised patients].

OBJECTIVE: To explore the distribution of etiological agents and death-relating factors of pulmonary infections in immunocompromised hosts(ICH). METHOD: 80 patients of pulmonary infections in ICH confirmed by etiological and(or) pathological diagnosis were retrospectively analyzed. RESULT: The distribution of etiological agents of pulmonary infections (except for cytomegalovirus, CMV): common bacteria 56%, mycobacterium tuberculosis 29%, fungus 11%, pneumocystis carinii 4%. Mortality of pulmonary infections in ICH showed significant difference between age 67% (> or = 60 years): 48% (< 60 years), bacteremia 86% (yes): 45% (no), white blood cell count 67%, 87% (> 10 x 10(9)/L, < 4.0 x 10(9)/L): 23% (4.0-10) x 10(9)/L, extent of lesions in x-ray film 65% (diffuse): 23% (local) (P < 0.05, P < 0.01), however, there was no obvious difference in sex, underlying diseases, types of etiological agents, mixed infections. CONCLUSION: Bacteria was one of the most common etiological agents of pulmonary infections in ICH, the latent reactivation and relapse of pulmonary tuberculosis in ICH should be emphasized sufficiently. The preliminary analysis of death-relating factors showed: age, bacteremia, white blood cell count, extent of lesions in x-ray film were related to the prognosis of pulmonary infections in ICH.

Adult↗

PubMed1998

[Relationship between elastase activity and leukocyte counts in gingival crevicular fluid].

OBJECTIVE: To determine the relationship among the elastase(EA) activity in the supernatant (EA-s), and in the pellet (EA-p) after centrifuge, and polymorphonuclear leukocyte (PMN) counts in gingival crevicular fluid. METHODS: Gingival crevicular fluid (GCF) was sampled with filter paper strips by intra-pocket method to determine EA levels and then with gingival crevicular washings after 24 hours at the same site for PMN counting. The levels of EA-s and EA-p were determined seperately using the subtract Meosuc-ala-ala-val-pro-NA. PMNs at the same site were counted with light microscope. RESULTS: The research demonstrated significantly positive correlation among EA-s and EA-p per site and the PMN counts in GCF (P < 0.001). CONCLUSION: GCF-EA-p per site could reflect the amount of PMNs collected from the pockets, and EA can be the marker of PMN in GCF.

Adult↗

PubMed1998

[An epidemiological survey of cleft lip and cleft palate in Fujian province].

OBJECTIVE: To find out the incidence of cleft lip and cleft palate in Fujian provice and to analysis the factors of its deformity. METHODS: From Oct. 1986 to Dec. 1992, the birth defect monitoring was carried out in 22 hospitals in Fujian province. RESULTS: It was found that there were 204 cases of cleft lip (CL) and cleft palate (CP) in 139,882 perinatals. The incidence rate of CL and/or CP was 1.46@1000. Annual incidence rate of CL and/or CP had not found any significant change. CONCLUSION: Among the 204 cases 28 had other deformities. The incidence rate of CL and/or CP related to maternal age, birth order, smoking factors were studied.

Adolescent↗

PubMed1998

[Comparison of sampling methods and their effects on alkaline phosphatase levels in gingival crevicular fluid].

OBJECTIVE: To observe the change of alkaline phosphatase (ALP) after repeat sampling and compare the two sampling methods (orifice method and intra-pocket method). METHODS: Gingival crevicular fluid (GCF) was sampled repeatedly by the interval of 20 minutes, with orifice and intra-pocket method respectively, and the levels of ALP in GCF were determined. RESULTS: Mean levels of ALP per site and concentration of ALP are not statistically different between two samples after repeat sampling with-orifice method as well as intra-pocket method (P > 0.05). ALP levels (per site and per microliter) are much higher for intra-pocket method than orifice method (P < 0.001). From the viewpoint of the numbers of recovery sites after repeat sampling, though ALP levels at most sites can't entirely recover to their original levels with both method, intra-pocket method is still a little better than orifice method, and ALP levels per site is better than ALP concentration. CONCLUSION: The interval of repeat sampling should be prolonged more than 20 minutes. It is better to determine the GCF-ALP with intra-pocket method and also the recommended pattern that express enzyme levels is total activity per site but not concentration.

Adult↗

PubMed1998

[The relationship between nm23-H1 loss of heterozygosity and metastasis in hepatocellular carcinoma].

OBJECTIVE: To demonstrate the relationship between nm23-H1 loss of heterozygosity (LOH) and clinical pathological characteristics of hepatocellular carcinoma (HCC) from the DNA level. METHOD: Southern blot hybridization was used to analyze genomic DNA in liver cancer and its corresponding liver tissue. RESULT: nm23-H1 has diallelic bands at 7.6 Kb and 2.3 Kb. Allelic loss of heterozygosity in tumour tissues was detected in 31.25% patients (5 patients). LOHs were more common in the tumours with intrahepatic metastasis or portal vein tumour embolism and the tumours poorly differentiated (Edmondson's classification III, IV). CONCLUSION: nm23-H1 LOHs may induce the metastasis potential of HCC and help to predict recurrence and metastasis of HCC.

Carcinoma, Hepatocellular↗

PubMed1998

[Synthesis and biological activity of 1-(4-alkyloxy)benzyl-1,2,3,4-tetrahydroisoquinolines and related compounds].

In an attempt to search for novel cardiovascular drugs which might act on calcium or potassium channels, on the basis of the previous study of our group, 15 1-(4-alkyloxy)benzyl-1,2,3,4-tetrahydroisoquinolines derivatives were designed and synthesized among which 10 were not reported previously in the literature. Preliminary pharmacological studies showed that most of these compounds exhibited relaxation of rat thoria aorta in vitro. Compound III9 exhibited potent inhibiting action on low KCl(20 mmol.L-1)-induced contraction of rat aorta, and significant protective effect on experimental arrhythmia in rats.

Animals↗

PubMed1998

[Synthesis and biological activity of 1-(4-acylamino)benzyl-1,2,3,4-tetrahydroisoquinolines].

For searching more effective antiarrhythmic agents, on the basis of integration of the structural feature of certain potassium channel blockers available, various acylamino groups were introduced to the position 4 of the benzyl ring of this series of compounds. Thus, eight 1-(4-acylamino)benzyl-1,2,3,4-tetrahydroisoquinolines were designed and synthesized, which had not been reported in the literatures. Compounds V1, V2 and V6 at concentration 10(-6) mol.L-1 depressed rat aortia contraction induced by high KCl (80 mmol.L-1). The effect was similar to that of tetrandrine. Compound V6 showed potent antiarrhythmic activity at the dosage of 1 mg.kg-1.

Aminoquinolines↗

PubMed1998

[Antisense oligodeoxynucleotide targeted at the pre-s region of DHBV could inhibit virus replication in vivo].

To study the antiviral effect of antisense oligodeoxynucleotide (AS-ODN), AS-ODN phosphotioates targeted to DHBV Pre-S region (951-968nt) (5'-TATCTCCTCCATTGTTTG-3') was synthesized. Two day-old ducklings were infected i.p. with 150 microliters of DHBV (3 x 10(8) copies/ml DHBV). After 12 days, 6 DHBsAg and DHBV DNA positive ducks were divided into two groups. In treated group, each duck was injected i.v. AS-ODN 20 micrograms/gram weight/day for 10 dyas successively, while in the control group, each duck received the same volume of normal saline for 10 days. Sera from ducks prior to treatment and treated after 6, 10 days were collected, and after 10 days ducks were sacrificed and livers were examined. DHBsAg was significantly decreased in all three treated ducks after 10 days of AS-ODN treatment. One of these ducks showed decreased DHBsAg even 6 days after treatment. Two out of three treated ducks showed decreased serum DHBV DNA, while one remained unchanged. In contrast, none of the control group showed decreased DHBsAg and DHBV DNA did not change. By Southern blot, DHBV DNA in the liver significantly decreased in 2/3 of the treated ducks and decreased in the other duck. In all control ducks, DHBV DNA remained strongly positive. Data indicated that AS-ODN targeting at Pre-S region could partly inhibit the replication of DHBV.

Animals↗

PubMed1998

Delta opioid receptor enhancement of mu opioid receptor-induced antinociception in spinal cord.

Although the mu selective agonist [D-Ala2-MePhe4-Gly-ol5]enkephalin (DAMGO) and the delta selective agonist [D-Pen2,D-Pen5]enkephalin (DPDPE) are both antinociceptive when administered directly into the spinal cord of mice, 50% of antinociceptive dose (AD50) of DAMGO is about 2 orders of magnitude lower than the AD50 of DPDPE. In contrast, the two ligands show similar affinities for their respective receptors in in vitro binding assays. One possible explanation for this discrepancy is that DPDPE antinociception in the spinal cord is mediated through not delta but mu receptors, for which it has an several hundred-fold lower affinity than DAMGO. In support of this, we found that DPDPE-mediated antinociception was blocked by the mu selective antagonist D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH2 (CTAP). The pA2 value of CTAP for DPDPE was virtually identical with that for DAMGO. However, because its action also was blocked by naltrindole, an antagonist selective for delta receptors, the latter must also play a role in antinociception. When DAMGO and DPDPE were administered i.t. together at ratios ranging from 1:200 to 1:500, the AD50 of DAMGO was lowered as much as 10-fold relative to its AD50 when given alone. Thus DPDPE had a potentiating effect on DAMGO, although the reverse was not observed. This potentiation was lost in animals made tolerant to systemic morphine. The loss of potentiation seemed to be caused by changes in the delta receptors, because a) the AD50 of DAMGO (i.t.) given alone to tolerant animals was virtually the same as for naive animals, whereas the AD50 of DPDPE given alone increased by 4-fold; and b) the AD50 of DPDPE given alone in the tolerant animal was increased only slightly by naltrindole, whereas CTAP was still a very potent antagonist. We conclude that DPDPE, a selective delta agonist, mediates antinociception in the spinal cord through mu receptors, consistent with results of recent studies of "knock-out" mice lacking mu receptors. At the same time, however, the delta agonist acting through delta receptors can potentiate the mu receptor-mediated antinociceptive action of either mu or delta agonists. This potentiating effect, like the synergistic effect observed between mu receptors at spinal and supraspinal sites, is lost during tolerance.

Analgesics↗

PubMed1997

A mammalian model for Laron syndrome produced by targeted disruption of the mouse growth hormone receptor/binding protein gene (the Laron mouse).

Laron syndrome [growth hormone (GH) insensitivity syndrome] is a hereditary dwarfism resulting from defects in the GH receptor (GHR) gene. GHR deficiency has not been reported in mammals other than humans. Many aspects of GHR dysfunction remain unknown because of ethical and practical limitations in studying humans. To create a mammalian model for this disease, we generated mice bearing a disrupted GHR/binding protein (GHR/BP) gene through a homologous gene targeting approach. Homozygous GHR/BP knockout mice showed severe postnatal growth retardation, proportionate dwarfism, absence of the GHR and GH binding protein, greatly decreased serum insulin-like growth factor I and elevated serum GH concentrations. These characteristics represent the phenotype typical of individuals with Laron syndrome. Animals heterozygous for the GHR/BP defect show only minimal growth impairment but have an intermediate biochemical phenotype, with decreased GHR and GH binding protein expression and slightly diminished insulin-like growth factor I levels. These findings indicate that the GHR/BP-deficient mouse (Laron mouse) is a suitable model for human Laron syndrome that will prove useful for the elucidation of many aspects of GHR/BP function that cannot be obtained in humans.

Animals↗