Search PubMed⌕ Search

Biomedical subjects

J He

Publications and source records attributed to J He.

At least 361 records · Page 20Linked to original sources
PubMed1995

Use of a novel human immunodeficiency virus type 1 reporter virus expressing human placental alkaline phosphatase to detect an alternative viral receptor.

We report here on the construction and use of a novel human immunodeficiency virus (HIV) type 1 reporter vector, HIV-AP, that encodes human placental alkaline phosphatase. Upon staining with chromogenic alkaline phosphatase substrates 24 to 36 h postinfection, cells infected with HIV-AP develop an intense purple color and can then be counted under a dissecting microscope. Alternatively, HIV-AP infectivity can be quantitated and infected cells can be sorted by a fluorescence-activated cell sorter after staining with a fluorescent alkaline phosphatase substrate. The assay is rapid and accurate, has very low background in a variety of cell lines and primary cells, and is not restricted to use in human cells. Infectious HIV-AP can be pseudotyped by various HIV or murine leukemia virus envelope glycoproteins. Using this virus, we have addressed the long-standing question of CD4-independent infection of cells by HIV. Our results confirm the presence on a human osteosarcoma cell line of an alternative receptor for HIV infection that functions with an efficiency approximately 1/20 that of CD4.

Alkaline Phosphatase↗
PubMed1995

Patterns of blood pressure variability in normotensive and hypertensive rats.

We sought patterns in mean arterial pressure of normotensive rats and alterations in chronic hypertension. Pressure was recorded for 4-6 days by telemetry from conscious, unrestrained rats and sampled digitally at 3 Hz, using normotensive Sprague-Dawley rats, spontaneously hypertensive rats (SHR), and Sprague-Dawley rats with two-kidney, one-clip renovascular hypertension (2K,1C). Time series analysis was by fast Fourier transform. Power spectra were divided into ultradian (frequencies > 1/day), circadian (frequency = 1/day), and infradian (frequencies < 1/day) domains. In the ultradian band from approximately 0.1 to 10 mHz the spectra were 1/f and without distinct peaks. The slopes were not significantly different among the groups and ranged from -1.03 to -1.61. At frequencies > 10 mHz, power continued to decrease but with a lower slope. A peak centered at approximately 100 mHz was present in both normotensive and 2K,1C rats but not in SHR. SHR had significantly more ultradian power than the others. The circadian rhythm modulated power in the ultradian band. Modulation was most prominent in normotensives, in which the ultradian activity was highest during the night when rats are active and lowest during the day; less pronounced in 2K,1C; and not detectable in SHR. There are regular patterns of blood pressure fluctuations and specific modifications to the patterns by different forms of hypertension.

Activity Cycles↗
PubMed1995

[Preconcentration of trace chromium in natural water with activated carbon and its determination by colorimetry].

The adsorption and desorption behavior of chromium was studied. Trace chromium in water could be adsorbed on activated carbon at pH 9-10, then eluted with 0.5% sulfuric acid and determined by colorimetry. The content of chromium could be concentrated by 100 times. For sample, the coefficient of variation of 8 parallel determinations was 7.7%. The proposed method has been applied to the determination of trace chromium in natural waters with the recovery of 71.4%-90.0%, and with the detection limit of 0.04 microgram/L.

Carbon↗
PubMed1995

Stroke in the People's Republic of China. I. Geographic variations in incidence and risk factors.

BACKGROUND AND PURPOSE: Stroke is a major cause of death in the People's Republic of China (PRC), and the geographic distribution of stroke death varies substantially. We conducted an ecological analysis to investigate the relationship of prevalence of hypertension and other risk factors with stroke incidence and mortality in the PRC. METHODS: The relationship between prevalence of risk factors and stroke incidence and mortality in the PRC was assessed in 29 provinces by examining risk factor data from PRC national surveys and incidence and mortality from the 1986 PRC National Stroke Study. RESULTS: A highly statistically significant correlation between prevalence of hypertension and stroke incidence (r = .838, P < .001) and mortality (r = .841, P < .001) was observed. Prevalence of hypertension explained over 70% of the geographic variability in stroke incidence (partial R2 = .703) and mortality (partial R2 = .707) in the PRC. There was a north-south gradient, with a higher prevalence of hypertension and stroke incidence and mortality in the north compared with the south of the country. In multiple Poisson regression analysis, a 10% increase in the prevalence of hypertension was associated with a 2.80-fold higher incidence and 2.68-fold higher mortality from stroke, whereas a 10% increase in the prevalence of alcohol consumption was associated with a 29% higher incidence and a 16% higher mortality from stroke. A 10% increase in the prevalence of cigarette smoking was associated with a 19% higher mortality from stroke. CONCLUSIONS: In the PRC, the prevalence of hypertension is strongly associated with the risk of stroke, and the geographic variation in stroke incidence and mortality is due mainly to differences in the prevalence of hypertension.

Adolescent↗
PubMed1995

Stroke in the People's Republic of China. II. Meta-analysis of hypertension and risk of stroke.

BACKGROUND AND PURPOSE: In the People's Republic of China (PRC), stroke accounts for over 1 million deaths per year, more than three times the number of deaths from ischemic heart disease. To quantify the effect of hypertension on stroke in the PRC, we conducted a meta-analysis and estimated the population attributable risk of stroke due to hypertension. METHODS: We searched the Chinese Medical Literature Index and MEDLINE databases to identify studies on the relationship between hypertension and stroke conducted in the PRC. The overall relative risk of stroke in hypertensive persons and the population attributable risk of stroke due to hypertension were calculated by pooling the risk estimates from individual studies. RESULTS: A total of 12 epidemiological studies with 2379 stroke cases was identified. The overall relative risk of stroke associated with hypertension was 5.43 (95% confidence interval [CI], 4.62 to 6.39). The relative risk was similar for hemorrhagic (5.44; 95% CI, 3.99 to 7.40) and ischemic (5.25; 95% CI, 3.95 to 6.98) stroke. On the basis of data from the 1990 PRC population census, vital statistics, and the 1991 PRC National Hypertension Survey, the excess annual mortality from stroke due to hypertension was estimated to be at least 545,000 deaths, with a population attributable risk of 49.5%. CONCLUSIONS: Our data suggest that hypertension is an important risk factor for stroke in the PRC and that hypertension may account for about half of all deaths from stroke in that country. Treatment and prevention of hypertension should be an important societal goal in the PRC.

Adult↗
PubMed1995

Radiotherapy of ectopic ACTH syndrome due to thoracic carcinoids.

From 1984 to 1990, six patients with histologically and endocrinologically proven ectopic ACTH syndrome were treated in our department. The lesion in five patients was clinically evident, but in the other was occult. All lesions were located within the chest. Four were thymic carcinoid and the other two were bronchial carcinoids. Most of the patients had typical clinical manifestations of Cushing's syndrome. Laboratory tests including histopathological examination confirmed the diagnosis of ectopic ACTH syndrome. The treatment consisted of surgical removal of the mass supplemented by radiotherapy. The results showed that after treatment all patients had satisfactory remission. Two bronchial carcinoid patients have been living for 40 and 88 months respectively without recurrence. Among 4 thymic carcinoid patients, only one has been living with no tumor for 34 months. One patient had recurrence and the other 2 died 32 and 50 months after the treatment respectively. However, the symptoms of two thymic carcinoid patients had not been relieved at all until radiotherapy was given. This paper discusses the method, dose and indications of radiotherapy. It should be pointed out that the prognosis of bronchial carcinoids is good while that of thymic carcinoids is relatively poor.

ACTH Syndrome, Ectopic↗
PubMed1995

Histidine ameliorated brain edema and cardiac dysfunction during local thrombotic cerebral ischemia in rats.

AIM: To observe the effects of histidine (i.v. 5 mg.kg-1) on brain edema and cardiac disturbance after cerebral thrombosis. METHODS: Regional cerebral thrombosis was induced by photochemical method in rats. RESULTS: It was showed that the brain water content increased markedly (85.6 +/- 3.8%, P < 0.01); the left ventricular systolic pressure (LVSP, 17.9 +/- 1.5 kPa) and the maximal left ventricular contractility decreased (+dp/dtmax 645 +/- 110 kPa and -dp/dtmax 473 +/- 106 kPa, P < 0.05). In rats treated with histidine after photochemical reaction, the brain water content decreased (81.5 +/- 2.0%) while LVSP (21.2 +/- 1.1 kPa) and left ventricular +dp/dtmax and -dp/dtmax increased markedly (777 +/- 144 kPa and 604 +/- 157 kPa, respectively). CONCLUSION: Histidine has protective effects on the brain and cardiac function during cerebral thrombosis.

Animals↗
PubMed1995

Homozygous deletions of the CDKN2 (MTS1/p16ink4) gene in cell lines established from children with acute lymphoblastic leukemia.

Homozygous deletions of the CDKN2 (MTS1/p16ink4) gene have been found at high frequency in cell lines derived from a variety of adult solid tumors. In order to investigate the status of the CDKN2 gene in cell lines established from childhood acute lymphoblastic leukemia (ALL), we surveyed 25 lines representing the major pediatric ALL phenotypes for the presence of this gene by Southern blot analysis. Homozygous deletions of all or part of the CDKN2 gene were detected in 21 (84%) cell lines, including 11 of 14 (79%) early-pre-B-ALL, four of five (80%) pre-B-ALL, and six of six T-ALL lines. CDN2 mRNA was detected by Northern blotting in each of the four lines containing an intact CDKN2 gene. These data suggest an important role for CDKN2 deletion in the cause and/or progression of pediatric ALL.

Blotting, Northern↗
PubMed1995

[Clinical significance of c-myc gene in esophageal squamous cell carcinoma].

Using polymerase chain reaction, we analysed 41 samples of esophageal squamous cell cancer at molecular level. Amplification of c-myc gene was found in 16 (39%). C-myc gene amplification was found to be related to lymph node metastasis, TNM staging (P < 0.01) and also prognosis (P < 0.05). We thought that c-myc gene was the prognosis factor for the patients with esophageal squamous cell carcinoma.

Adult↗
PubMed1995

[Preparation of oral berberine bisulfate liposomes].

The co-precipitate has been made from berberine bisulfate and polyvingyl pyrrolidone (PVP) with the ratio of 1 : 5. The liposomes entrapped berberine bisulfate have been prepared with the ration of drug to lipid 1 : 20 and the ratio of cholesterol to soy phosphatide 2 : 7. The percentage of encapsulation is 48.72%. The test in vivo of small intestinal absorption in rats shows that liposomes can increase the absorption by 4-fold odd compared with free ber-berine bisulfate.

Animals↗
PubMed1994

Effect of hydroxyurea on 2',3'-dideoxycytidine activation.

The effect of hydroxyurea (HU) on cell growth, cell cycle progression, and the intracellular accumulation of 2',3'-dideoxycytidine (ddC) and ddCTP formation was examined. Twenty-four-hour exposure of H9 cells (human lymphocytic cell line) to 500 microM HU significantly increased the cells in the G1 phase and inhibited cell growth to 33.3 +/- 10.6% of control. The total intracellular ddC and ddCTP accumulation in HU-treated cells increased to 232.3% and 310% of control, respectively.

Biotransformation↗
PubMed1994

CDK4 amplification is an alternative mechanism to p16 gene homozygous deletion in glioma cell lines.

Recently, it has been shown that a gene encoding the cyclin-dependent kinase 4 inhibitory protein, p16, is frequently targeted for homozygous deletions in several types of tumor cell lines, including those established from malignant gliomas. Here we have examined 32 glioma cell lines for amplification-associated overexpression of the CDK4 gene as an alternative mechanism for abrogating the growth-regulatory effects of p16. Two of the cell lines revealed high-level expression of CDK4 in association with gene amplification, and this alteration was observed among the 10 cases having intact p16 genes. Consequently, 24 of 32 glioma cell lines revealed one of two alternative genetic alterations, each of which indicates that increased cdk4 kinase activity is important to glial tumor development.

Base Sequence↗
PubMed1994

Short- and long-term prognosis after acute myocardial infarction in Chinese men and women.

Most, but not all, studies in Western countries have indicated that women have a higher mortality than men after an acute myocardial infarction, but this has not been well documented in the developing world. The authors studied 601 male and 294 female myocardial infarction patients, aged 26-94 years, admitted to a city hospital in Beijing, China, between 1974 and 1986. A total of 745 (98.8%) of the cohort of 754 who survived past their initial hospitalization were followed up in 1988. Compared with their male counterparts, female myocardial infarction patients were older (63.4 vs. 58.1 years) and had a higher prevalence of tachycardia (heart rate, > or = 110 beats/minute), rales, New York Heart Association class III or IV, and heart block, but a lower prevalence of smoking and white collar occupation (all p < 0.01). The mortality within 28 days of their myocardial infarction was higher in women than in men, mainly in the group whose age was less than 60 years (20.4% vs. 7.1%, p < 0.001). The greater risk of short-term mortality in women persisted even after adjustment for age, history of stroke and hypertension, tachycardia on admission, anterior infarction, Killip class III or IV, and arrhythmia (relative odds = 1.74, 95% confidence interval 1.17-2.60). The 10-year total cumulative mortality in persons who survived the first 28 days following their myocardial infarction was 51.1% for women and 35.9% for men (log rank p = 0.002). After adjustment for age, this difference was not statistically significant (p = 0.3). Our results suggest that, in Beijing, women have a higher short-term mortality after myocardial infarction compared with men.

Adult↗
PubMed1994

Correction of accelerated autoimmune disease by early replacement of the mutated lpr gene with the normal Fas apoptosis gene in the T cells of transgenic MRL-lpr/lpr mice.

MRL-lpr/lpr mice develop a generalized autoimmune disease which includes increased autoantibody production, glomerulonephritis, and development of lymphadenopathy. The lpr genetic defect has been identified as a mutation in the Fas apoptosis gene that results in low expression of Fas mRNA. To determine the significance of the lpr mutation and T cells in the development of the autoimmune disease, we constructed transgenic MRL-lpr/lpr mice using a full-length murine Fas cDNA under the regulation of the T-cell-specific CD2 promoter and enhancer. Here we show that the early correction of the lpr gene defect in T cells eliminates glomerulonephritis and development of lymphadenopathy and decreases the levels of autoantibodies. In this model, early correction of the lpr defect in T cells is sufficient to eliminate the acceleration of autoimmune disease even in the presence of B cells and other cells that express the mutant lpr gene.

Animals↗
PubMed1994

Body mass and blood pressure in a lean population in southwestern China.

Body mass has been consistently associated with blood pressure in acculturated populations but not in lean populations with low blood pressures. In southwestern China, in 1989, the authors studied the relation between body mass and blood pressure in three community-based random samples: rural Yi farmers (5,023 men, 3,218 women); Yi migrants (1,656 men, 919 women); and Han Chinese living in an urban setting (2,173 men, 1,516 women). The Yi farmers had virtually no obesity or hypertension and had little rise in blood pressure with age. The Yi migrants and Han had a steeper slope of blood pressure with age and consequently more hypertension. For men and women, respectively, mean body mass index (weight (kg)/height (m)2) was 20.6 and 21.0 in the Yi farmers, 21.3 and 21.4 in the Yi migrants, and 21.0 and 21.4 in the Han. Both systolic and diastolic blood pressure were positively related to body mass index in all six ethnicity-sex groups, and the association remained statistically significant after adjustment for age, heart rate, smoking, alcohol intake, and physical activity. The change in mean blood pressure for each kg/m2 increase in body mass index, after adjustment for community of residence, was 1.47 mmHg for systolic pressure and 1.13 mmHg for diastolic pressure. The association between body mass index and blood pressure was greater in men than in women and greater in Yi migrants and Han than in Yi farmers. The percentages of hypertension attributable to overweight (body mass index > or = 25) among the Yi farmers, Yi migrants, and Han, respectively, were 4.1%, 34.1%, and 24.0% for men and 0%, 26.2%, and 28.9% for women. Thus, even in this lean Chinese population with a low mean blood pressure, body mass was positively and independently associated with increased blood pressure.

Adolescent↗
PubMed1994

Iron-induced conformational change in human lactoferrin: demonstration by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and analysis of effects of iron binding to the N and C lobes of the molecule.

Analysis of Fe-saturated- and apo-lactoferrin by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) without heating the samples prior to application revealed a substantial difference in mobility. The mobility shift was fully reversible on repetitive removal and readdition of Fe. Binding of a single Fe to the N-lobe binding site was sufficient to cause the gel shift; binding of a second Fe to the C-lobe site did not further alter mobility. Removal of Fe from the N lobe of Fe2 lactoferrin did not restore mobility to the position of apolactoferrin. No change in mobility with Fe binding was detected in N and C lobes isolated from intact lactoferrin by controlled trypsin digestion. The data indicate that a conformational change induced by Fe binding to a single site on lactoferrin is detectable by SDS-PAGE and that this change requires an intact molecule, possibly due to the need for interactions between the two homologous lobes of the molecule.

Apoproteins↗
PubMed1994

Analysis of glioma cell lines for amplification and overexpression of MDM2.

Recently, amplification of the gene encoding a p53 binding protein, MDM2, was determined in 8% of the cases constituting a large series of glioblastomas. Here we have utilized Southern blot analysis to examine 30 cell lines established from such tumors, and our investigation has revealed large increases in MDM2 gene dosage in two cases, one of which showed coamplification of the CDK4 gene that resides in close proximity to MDM2 in chromosomal region 12q13-14. Northern analysis demonstrated overexpression of MDM2 mRNA in the two cell lines with gene amplification, and overexpression of MDM2 protein was evident in each of these by immunohistochemical and Western blot analysis. Analysis of TP53 cDNAs revealed normal TP53 sequences in the cell lines with MDM2 amplification; these results are consistent with those of previous studies suggesting that MDM2 amplification occurs only in tumors expressing wild-type p53. In total, these data suggest that MDM2 amplification in glioblastoma cell lines occurs at a frequency (6.7%) comparable to that determined in primary tumors; occurs in cell lines expressing wild-type p53; and can involve the coamplification of additional genes.

Gene Amplification↗