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Biomedical subjects

F He

Publications and source records attributed to F He.

At least 91 records · Page 5Linked to original sources
PubMed1999

Spontaneous activation of hamster oocytes in vitro.

OBJECTIVES: To observe the time of spontaneous activation of hamster oocytes and to find out the early signs of hamster oocytes activation. METHODS: First, 63 hamster oocytes including activated and non-activated oocytes (group A) and 51 non-activated oocytes (group B) were injected with human sperm and checked for fertilization after 16-18 hours. Then, 20 hamster oocytes were cultured in vitro in medium with or without calcium and examined under light microscope every half an hour up to 9 hours. RESULTS: Under light microscope, hamster oocytes activation were observed to undergo 4 stages: metaphase II stage without meiotic spindle, appearance of meiotic spindle near the first polar body, protrusion of oolemma, and complete extrusion of second polar body with pronucleus formation. After culture for 1.5 hours in vitro, 30%-40% of the oocytes demonstrated meiotic spindle; but after 9 hours, 50% showed complete activation. Culture in medium without calcium showed a little delay in the process of activation. The earliest sign of spontaneous activation in hamster oocytes was the appearance of meiotic spindle near the first polar body. Although group A and B showed no difference, the damage rate was lower in group B (19.7% +/- 16.6%) than in group A (35.9% +/- 5.7%) (P = 0.08), whereas the fertilization rate (18.3% +/- 10.9%) was higher in group B than in group A (14.2% +/- 8.7%) (P = 0.135). CONCLUSIONS: Hamster oocytes may be activated spontaneously early after their removal. It is important to recognize the earliest sign of spontaneous activation and perform intracytoplasmic sperm injection (ICSI) before it happens.

Animals↗
PubMed1999

[Genetic polymorphism and susceptibility to occupational chronic manganism: a case-control study].

OBJECTIVE: In a case-control study, the possible genetic factors relevance to occupational chronic manganism were investigated. METHODS: Forty-nine manganisms who were welders and ferromanganese smelters occupationally exposed to manganese dust and fume from three metallurgical industries, and fifty unrelated healthy control subjects who were working same workshops were recruited. The subjects were matched for sex, age, cigarette and alcohol intake. The manganese exposure duration was also matched in this case-control study. Genetic polymorphism of cytochrome P450 2D6L (CYP2D6L) gene and NAD(P)H: quinone oxidreductase (NQO1) genes from all subjects were investigated. The mutations of CYP2D6L gene located exon 6 were analyzed by a polymerase chain reaction (PCR)-based DNA amplification combined with Hha I restriction fragment length polymorphism (RFLP). The substitution of 609(C-T) at exon 6 of DT-diaphroase gene was analyzed by PCR combined Hinf I RFLP. RESULTS: The frequency of polymorphic allels, a mutation of CYP2D6, was significantly lower in patients with manganism (16.3%) than that of the controls (29.0%). A significant association was also found between the homozygote variant of CYP2D6L gene and occupational manganism. These results suggest that the CYP2D6 gene might be one of the susceptibility genes for Mn-induced neurotoxicity. The allele and genotype frequencies of NQO1 gene were similar in the manganism cases and control subjects. CONCLUSION: It is possible that CYP2D6 gene may be a valuable susceptibility biomarker responded to Mn-induced central nervous system disorders in workers exposed to manganese.

Adult↗
PubMed1998

Tyrosine kinase expression profiles of chicken erythro-progenitor cells and oncogene-transformed erythroblasts.

Tyrosine kinases are implicated in the growth and differentiation of erythroid cells. Aberrant expression and structural alterations of certain tyrosine kinases, such as erbB and sea, are known to trigger erythroleukemia development. To facilitate our understanding of the signal transduction pathways involved in erythroid differentiation and leukemic transformation, we have applied a recently developed tyrosine kinase profile technique to identify the tyrosine kinases and some novel serine/threonine kinases expressed in normal chicken erythroid progenitor cells that respond to TGFalpha (TGFalpha-EB), and erythroblasts transformed by viruses encoding v-erbB (v-erbB-EB) and v-sea (v-sea-EB). Our results reveal that the non-receptor tyrosine kinases, Abl, Fyn, Lyn, Btk and Csk, are expressed in all three cell types. The expression level of Btk, a tyrosine kinase implicated in Bruton's syndrome, is exceptionally high in the erythroblastoid cell line 6C2, transformed by the v-erbB carrying avian erythroblastosis virus, AEV-ES4. We have also uncovered a new STE-20-related serine/threonine kinase, KFC, which is abundantly expressed in both the TGFalpha-stimulated erythroid progenitor cells and v-sea-transformed erythroblasts. Based on sequence homology of the kinase domain, KFC appears to be the first member of a new subfamily of STE-20-like kinases.

Amino Acid Sequence↗
PubMed1998

Intermediate myasthenia syndrome following acute organophosphates poisoning--an analysis of 21 cases.

1. Twenty-one cases out of 272 patients of acute organophosphates poisoning were diagnosed as intermediate syndrome (IMS) with a prevalence at 7.7%. The responsible OP insecticides included parathion, omethoate and some OP containing pesticide mixtures. IMS occurred mainly in severe OP poisoning patients who recovered from the acute cholinergic crisis at 7-75 h after the onset of acute poisoning. 2. Muscular weakness appeared in the following three categories of muscles: (1) neck flexors and proximal limb muscles; (2) muscles innervated by motor cranial nerves and/or (3) respiratory muscles. Blood acetylcholinesterase activity was persistently inhibited. Electroneuromyography (ENMG) with repetitive nerve stimulation (RNS) at frequencies of 20 Hz or 30 Hz in seven patients showed decrements of common muscle action potentials during the presence of myasthenia in five patients and became normal when their muscle strength recovered. 3. Mild IMS recovered within 2-7 days and had a favorable prognosis. Severe IMS patients with respiratory paralysis needed immediate endotracheal intubation and mechanical ventilation. Recovery of weakness of the respiratory muscles and proximal limb muscles took longer, the slowest being 30 days. Four of the patients died of respiratory paralysis and the fatality rate was 19%. 4. The mechanism of IMS remains to be further investigated. The RNS/ENMG changes indicate a post-synaptic block at the neuromuscular junctions. 5. In order to promote the recognition of this syndrome, we proposed to name the syndrome as Intermediate Myasthenia Syndrome (IMS).

Adolescent↗
PubMed1998

Evaluation of a safety educational programme for the prevention of pesticide poisoning.

The causal factors of pesticide poisoning in spraymen usually include sloppy handling, leakage of sprayers and a lack of personal protection, as well as of a knowledge about pesticide toxicity. This paper outlines the results of a safety educational programme to prevent pesticide poisoning among Chinese village spraymen in 1991 and 1992. The programme consisted of two parts: an interview of 3,286 trained subjects who were surveyed before and after the education courses, and a survey on the prevalence of pesticide poisoning among spraymen in 10 villages in 1991 and 1992, respectively. The results showed a general improvement in the knowledge about pesticide toxicity and safe use among the surveyed subjects. The prevalence of pesticide poisoning among the surveyed spraymen decreased from 1.05% in 1991 to 0.25% in 1992. Moreover, a 68.2% reduction of pesticide poisoning cases was observed in 10 villages in 1992. The success of the safety educational programme proved that education is an effective measure for preventing pesticide poisoning.

Adult↗
PubMed1998

[Radioimmunoimaging of hepatocellular carcinoma with 131I labeled antihepatoma monoclonal antibody Fab fragment].

OBJECTIVE: To study the effects of radioimmunoimaging (R11) of hepatocellular carcinoma with 131I labeled antihepatoma monoclonal antibody (HAb18) Fab fragment. METHODS: HAb18Fab was prepared by papain digesting HAb18, and it was radioiodinated with iodine-131 using high efficiency iodination method. The experiment consisted of two parts: ten nud mice bearing human hepatocellular carcinoma xenograft were injected intravenously with 131I-HAb18Fab 3,700 kBq/mouse, and six patients with hepatocellular carcinoma were injected intravenously with 131I-HAb18Fab 111-166.5 mBq/body. RESULTS: Ten nud mice bearing hepatocellular carcinoma, showed positive image. The optimum imaging time was 4.5-12 h after injection, and was 21.07 +/- 0.05 for tumor/liver higher than 5.83 +/- 0.05 of intact HAb18, and the reported 3.03. No tumor image was found in the control group of mice. Six patients with hepatocellular carcinoma, after injecting 131I-HAb18Fab 16 h, showed positive image. The optimum imaging time was 16-24 h earlier than 96 h of the reported 131I. CONCLUSION: R11 with 131I-HAb18Fab possesses the advantages of the location, qualitative analysis and earlier diagnosis. It is prospective in clinical application.

Animals↗
PubMed1998

[Study of experimental mixed bone marrow transplantation].

OBJECTIVE: To explore strategies for preventing graft versus host disease (GVHD) while preserving graft versus leukemia (GVL) effects in allogeneic bone marrow transplantation(BMT). METHODS: Allogeneic bone marrow and spleen cells mixed with syngeneic spleen/bone marrow cells were transplanted into lethally irradiated inbred mice. The mortality of the recipient mice from GVHD, the number of CFU-S, the origin of the bone marrow cells responsible for the reconstitution at different time after transplantation and the proliferative reaction against the stimulating cells from the syngeneic or allogeneic mice were observed and compared with those in the conventional syngeneic and allogeneic BMT. L615 leukemia model was used to evaluate the GVL effect of mixed BMT. RESULTS: Lethal GVHD was effectively prevented by the syngeneic spleen cells which showed no harmful effect on the CFU-S reconstitution. The medium survival time of the mixed transplanted L615 mice was significantly prolonged. CONCLUSION: The grafts composed of allogeneic bone marrow and spleen cells mixed with syngeneic spleen cells, make the recipient mice have transient GVL effects resulted from the MHC mismatched immunocompetent cells and alleviated the severe GVHD of allogeneic BMT.

Animals↗
PubMed1998

Protective effect of recombinant human augmenter of liver regeneration on CCl4-induced hepatitis in mice.

OBJECTIVE: To observe the anti-injury role of recombinant human augmenter of liver regeneration. METHODS: To establish liver injury models induced by CCl4 in vivo and in vitro, cell survival rates and LDH release rates served as observing index in experiments in vitro. Survival rates of liver failure animals, serum concentration of ALT, LDH, DNA and pathological examination were selected as parameters in experiment in vivo. RESULTS: rhALR could increase the survival rates and decrease the LDH release rates of injured hepatocytes in vitro. rhALR could also increase the survival rates of liver failure animal, promote hepatocyte proliferation and decrease the serum level of ALT and LDH in vivo. CONCLUSION: ALR is an important stimulator for liver regeneration and may play important role in liver damage repair.

Animals↗
PubMed1997

Mast cells and nerve fibers in interstitial cystitis (IC): an algorithm for histologic diagnosis via quantitative image analysis and morphometry (QIAM).

OBJECTIVE: To develop and evaluate a diagnostic algorithm based on the alteration of mast cell and nerve fiber observed in bladder tissue of patients with interstitial cystitis (IC). MATERIALS AND METHODS: Non-IC samples from 6 control groups (N = 10, 10, 13, 2, 11, and 3, respectively) and nonclassic interstitial cystitis (NC-IC, N = 20) were stained with Giemsa stain in order to calculate the detrusor to mucosa mast cell ratio (DMMCR) using quantitative image analysis and morphometry (QIAM). Immunohistochemical staining for S-100 protein was also performed to quantify nerve fiber proliferation in the detrusor muscle of the bladder. RESULTS: The average DMMCR of NC-IC was 1.19. Bacille Calmette-Guérin (BCG) cystitis was 0.84 and microscopically normal bladder tissue from patients with bladder or prostate cancer was 0.45. No case of IC that we examined had a DMMCR < 0.5. The number and percentage area of nerve fibers in the detrusor in IC were increased compared to controls and BCG (IC, 2.01%; BCG, 0.95%; control, 1.3%). CONCLUSION: A diagnostic algorithm is proposed for IC based on the findings that indicate that: 1) if the DMMCR > 0.75, then IC is present; 2) if the DMMCR < 0.5, then IC is negative; and 3) if the DMMCR is between 0.5 and 0.75, a quantitative S-100 protein staining analysis can be employed to evaluate nerve fiber proliferation to detect those marginal cases of NC-IC. The findings of the study also suggest that a neuroimmune process or mediation may be involved in the pathogenesis of IC.

Algorithms↗
PubMed1997

Upf1p, Nmd2p, and Upf3p are interacting components of the yeast nonsense-mediated mRNA decay pathway.

Rapid turnover of nonsense-containing mRNAs in Saccharomyces cerevisiae is dependent on Upf1p, Nmd2p, and Upf3p, the products of the UPF1, NMD2/UPF2, and UPF3 genes, respectively. We showed previously that Upf1p and Nmd2p interact and that this interaction is required for nonsense-mediated mRNA decay (F. He and A. Jacobson, Genes Dev. 9:437-454, 1995; F. He, A. H. Brown, and A. Jacobson, RNA 2:153-170, 1996). In this study we have used the yeast two-hybrid system to define other protein-protein interactions among the essential components of this decay pathway. Nmd2p-Upf3p and Upf1p-Upf3p interactions were identified, and the respective domains involved in these interactions were delineated by deletion analysis. The domains of Upf1p and Upf3p putatively involved in their mutual interaction were found to correspond to the domains on the two proteins which interact with Nmd2p, suggesting that Nmd2p bridges Upf1p and Upf3p. This conclusion was reinforced by experiments showing that: (i) deletion of NMD2 completely abolishes interactions between Upf1p and Upf3p and (ii) overexpression of full-length Nmd2p or Nmd2p fragments that retain Upf1p- and Upf3p-interacting domains promotes 10- to 200-fold enhancement of Upf1p-Nmd2p-Upf3p complex formation. These results; the observation that cells harboring either single or multiple deletions of UPF1, NMD2, and UPF3 inhibit nonsense-mediated mRNA decay to the same extent; and an analysis of the possible targets of a dominant-negative NMD2 allele indicate that Upf1p, Nmd2p, Upf3p, and at least one other factor are functionally dependent, interacting components of the yeast nonsense-mediated mRNA decay pathway.

Adaptor Proteins, Signal Transducing↗
PubMed1997

[Blocking effects of dimethoate on acetylcholine receptor channels].

The patch-clamp technique was used to study the inhibitory effect of dimethoate, an organophosphrous pesticide, on the membrane of embryoinc Xenopus musle cells in culture. Using whole-cell clamp and cell-attached clamp, we found that the direct inhibitory effects of dimethoate was evidenced on both miniature end-plate currents (MEPC) and single channel currents. Dimethoate increased the amplitude and frequency of MEPC at a lower concentration (21.6 mumol/L) while both decreased at a higher concentration (237 mumol/L). The dimethoate at a concentration of 146 mumol/L shortened the opening time and decreased the opening probability of the single channel. The results show that dimethoate is an AChR channel blocker.

Animals↗
PubMed1997

[Analysis of the vol atiles from pigeon's excrement with capillary gas chromatography].

The volatiles from pigeon's excrement were obtained with a simultaneous distillation and extraction (SDE) equipment. The chemical composition of the volatiles was examined by means of capillary gas chromatography and combined gas chromatography-mass spectrometry. Forty seven constitutents of the volatiles were identified by gas chromatography-mass spectrometry. Of these compounds, thirty nine were further identified by measuring their temperature-programmed retention indexes or retention times on OV-1 and PEG-20M columns and making comparison with those of the corresponding authentic samples. The total compounds identified make 57% of the total peak areas. The compound classes consist of alcohols (4), aldehydes (11), ketones(4), acids (8), esters (5), and phenols (2), amounting to 43.68% of the total peak areas. The ten compounds with highest contents are, hexadecanoic acid (9.03%), ethyl acetate (6.85%), ethanol (4.03%), 1-ethoxy-2-methylpropane (3.87%), acetic acid (3.23%), heptadecane-(8)-carbonic acid (3.20%), (Z,Z)-9,12-octadecadienoic acid (3.18%), nonanal (2.85%), 1,2-benzenedicarboxylic, dibutyl ester (2.65%), and acetaldehyde (2.32%). Pigeon's excrement has long been used as a Chinese traditional medicine for the therapeutic treatment of haemorrhoid. Some of the constituents identified in the work have been reported to have antibacterial activities.

Animals↗
PubMed1997

[Research of the effect of ascorbic acid prereduced Pd in the determination of micro quantity of Mn with GFAAS].

In this article, method of determination of micro quantity of Mn with GFAAS and Pd have been researched, results of different additional methods of Pd were compared the combining energy of Pd in three heating steps were determined by X-ray Photoelectron Spectroscopy. The point was given that as a catalyst reduced Pd changed courses of Mn atomization, and when pre-reduced Pd was used because of its much larger surface area, method had much better RSD and had much stronger signal than other methods in those cases Pd was used too.

Ascorbic Acid↗
PubMed1997

[Cloning and squencing of human thrombopoietin (hTPO) cDNA and it's expression in COS-7 cells].

Two hTPO cDNA segments (N-terminal and C-terminal) were amplified from human fetal liver mRNA by using separate reverse-transcription PCR reactions, and cloned into pUC19. Their sequences were identical with that previously reported. Then the full length cDNA of hTPO was obtained from the two cDNA fragments, cloned into the shuttle vector pSVK3 and transiently expressed in COS-7 cells. The activity of the expression product was demonstrated with the stimulation of CFU-Meg.

Animals↗