Search PubMed⌕ Search

Biomedical subjects

Y Huang

Publications and source records attributed to Y Huang.

At least 775 records · Page 43Linked to original sources

[Extraction, purification and ascertainment of anti-hepatoma active principles for targeted preparation of radix Aconiti Kusnezoffii].

The extraction, purification, pharmacological experiments and chemical analysis of anti-hepatoma active principles of Radix Aconiti Kusnezoffii have been studied. The results show that the medicinal material Radix Aconiti Kusnezoffii is efficacious in inhibiting hepatoma, and the active principles are mainly made up of poisonous ester alkaloids. The liver targeting delivery system will be the first choice for its anti-hepatoma preparation, and the effective component AY3a is fit for the preparation of targeted microspheres.

Aconitum↗

[The study on SDS-PAGE technic classification of the whole protein of oral bacteria].

Oral flora was classificated by SDS-PAGE combined with Comassie blue staining and silver staining. The results showed that each species of the test oral bacteria expressed its specific electrophorectic protein pattern, the way of sample preparation, staining did not change the protein pattern. This indicated that SDS-PAGE could be used to classificate oral flora. The protein pattern was more obvious among the genus than that of within the genus. This showed that different relationship was among the bacteria.

Actinomyces viscosus↗

[Human dynamic equations and analysis of opening the hatch door under weightlessness].

The general human dynamic equations under weightlessness were derived using Kane-Huston's Method. According to manned spaceflight circumstances, specific equations for models of floating in space and having a single point support were derived from the above general equations. The action that the astronaut opens the hatch door was analyzed, the "float" evolution was calculated, and the evolutionary curves were drawn.

Anthropometry↗

[Pharmacognostical identification of Anoectochilus roxburghii].

This paper reported the pharmacognostical identification on characters, microscopic characteristics and TLC of the Anoectochilus roxburghii (Wall.) Lindl., and compared with different resouce samples. The results may provide reference for its identification.

Chromatography, Thin Layer↗

[Pharmacokinetics of intravenous arsenic trioxide in the treatment of acute promyelocytic leukemia].

OBJECTIVE: In order to study the pharmacokinetics and metabolism of arsenic trioxide (As22O3), and its major side effects. METHODS: The clinical pharmacokinetics of intravenous As2O3 in 8 relapsed acute promyelocytic leukemia (APL) patients were studied by Gas-phase chromotography. RESULTS: (1) After 2 hour intravenous drips of 10mg As2O3, drug plasma maximal concentration (Cpmax) was 0.94 +/- 0.37mg/L(x +/- s), time to peak concentration (Tp) was 4hrs, T1/2 alpha and T1/2beta were 0.89 +/- 0.29hrs and 12.13 +/- 3.31hrs, respectively, apparent volume of distribution (Vc) was 3.83 +/- 0.45L, system clearance (CLs) was 1.43 +/- 0.17L/h and area under curve (AUC) was 7.25 +/- 0.97mg x h/L. Importantly, the continuous administration of As2O3 did not alter the pharmacokinetic behaviors. (2) During As2O3 therapy, 24-hour arsenic content in urine accounted for 1%-8% of the total dose (10mg) per day. And it decreased gradually after drug withdrawal. (3) Arsenic contents in nail and hair were increased continuously during As2O3 therapy. The peak concentrations could be five to seven-fold higher than that pre-treatment. It also decreased gradually after drug with drawal. CONCLUSION: As2O3 is a relatively safe and effective drug in the treatment of APL patients, in spite of certain accumulation in some tissues.

Adolescent↗

[The change of trace elements content in hair during the period of gestation].

Study on trace elements content change in hair during the period of gestation for 52 lying-in women was performed. The quantitative results for 7 elements have been obtained and the change tendencies for other 7 elements without standard value have been observed on the basis of a self comparison method for each individual.

Female↗

Transcriptional and post-transcriptional regulation of LDL receptor gene expression in PMA-treated THP-1 cells by LDL-containing immune complexes.

We have previously shown that uptake of low density lipoprotein-containing immune complexes (LDL-IC) by human monocyte-derived macrophages led to the transformation of these cells into foam cells and induced a paradoxical increase in receptor-mediated binding of 125I-labeled LDL due to an increase in the number of LDL receptors (LDL-R). The same metabolic changes are also observed in PMA-treated THP-1 cells after incubation for 2 h with 150 microg/ml of immune complexes containing either native, oxidized (ox), or malondialdehyde (mda) LDL. After stimulation, PMA-treated THP-1 cells showed not only a 40-fold increase in 125I-labeled LDL binding but also a 40-fold increase in the immunoreactive LDL-R protein, confirming that the increase in LDL binding is due to an increase LDL-R number. In this study we have investigated, in PMA-treated THP-1 cells, the regulatory mechanism(s) responsible for the increased receptor-mediated binding of LDL induced by LDL-IC. By Northern blot and nuclear run-on analysis we have shown transcriptional activation of the LDL-R gene with a 7-fold increase in the LDL-R mRNA level in LDL-IC stimulated cells. Due to the marked difference between the increase in LDL-R mRNA and LDL-R protein, we estimated LDL-R mRNA stability using a inhibitor chase method and have shown that LDL-IC did not alter the LDL-R mRNA stability in THP-1 cells. We have also demonstrated, using cycloheximide as a inhibitor of protein synthesis, that the marked increase in LDL-R protein observed in LDL-IC-stimulated THP-1 cells resulted from de novo synthesis of LDL-R protein. To determine whether the increase in transcriptional activity of the LDL-R gene was secondary to changes in the cholesterol regulatory pool we performed experiments in which the cell cholesterol content was modified by the addition of either 25-hydroxycholesterol and mevalonate or inhibitors of ACAT activity (SA-58035 and progesterone). These experiments showed that the enhanced LDL-R expression was not affected by the addition of any of the above compounds. In conclusion, LDL-IC induced both transcriptional and post-transcriptional activation of the LDL-R gene in PMA-treated THP-1 cells and this induction was independent of the free cholesterol content of these cells.

Antigen-Antibody Complex↗

Prophylactic antibiotic project.

This project evaluated the use of prophylactic antibiotics within two hours prior to selected surgical procedures. Even with knee arthroplasty, for which there is essentially universal agreement on the need for prophylactic antibiotics, there is room for improvement in antibiotic delivery. This is true both in the percent of patients receiving antibiotics and the timeliness of administration. Although there is some difference of opinion about the advisability of prophylactic antibiotics for certain procedures, the preponderance of recent literature advocates its use and this is a quality indicator evaluated by JCAHO.

Antibiotic Prophylaxis↗

Pneumonia I and Pneumonia II Projects.

The need for timely and efficient treatment is assuming even greater significance, with pneumonia discharges increasing from 5,862 in 1992 to 7,870 in 1994. These two projects, involving a total of 13 hospitals, evaluated the timeliness of antibiotic administration for pneumonia patients. Baseline data revealed opportunities for improving process of care at all hospitals. After implementation of improvement plans, the majority of hospitals increased the percentage of patients receiving antibiotics within four hours of admission. This evaluation of the antibiotic delivery system can also be adapted to other diagnoses and medications.

Anti-Bacterial Agents↗

A natural apolipoprotein A-I variant, apoA-I (L141R)Pisa, interferes with the formation of alpha-high density lipoproteins (HDL) but not with the formation of pre beta 1-HDL and influences efflux of cholesterol into plasma.

ApoA-I(L141R)Pisa is a naturally occurring apolipoprotein A-I variant that causes virtual absence of HDL in hemizygotes and hypoalphalipoproteinemia with half-normal levels of HDL-cholesterol in heterozygotes. In this study we analyzed the distribution of HDL subclasses in plasmas of four hemizygotes for this mutation. We also investigated the abilities of these plasmas to esterify cholesterol and to promote cholesterol efflux. Residual apoA-I-containing lipoproteins in plasmas of hemizygotes for apoA-I(L141R)Pisa correspond to pre beta 1-LpA-I and small alpha-LpA-I. Unlike normal pre beta 1-LpA-I, pre beta 1-LpA-I of apoA-I(L141R)Pisa hemizygotes was not converted into a larger alpha-migrating particle. Plasmas of apoA-I(L141R)Pisa hemizygotes were significantly reduced in their activity to esterify cholesterol in either endogenous or exogenous lipoproteins. Cholesterol efflux capacity was significantly lower than that of normal plasma. Efflux of [3H] cholesterol from radiolabeled fibroblasts into apoB-depleted plasma of normal probands was biphasic with fast cholesterol efflux occurring in the first minute. Thereafter, cholesterol efflux was slow and unsaturable. After incubation with radiolabeled fibroblasts, efflux values of [3H]cholesterol into apoB-depleted plasma from normal controls and from apoA-I(L141R)Pisa hemizygotes were indistinguishable at 1 min. Longer incubations with apoB-free plasma from apoA-I(L141R)Pisa hemizygotes did not, however, lead to the unsaturable increase in cholesterol efflux that was observed during incubations with apoB-free plasma of normolipidemic probands. Pre beta 1-LpA-I of apoA-I(L141R)Pisa hemizygotes took up significantly less cell-derived [3H]cholesterol than pre beta 1-LpA-I of normal donors. We conclude that apoA-I(L141R)Pisa interferes with the formation of lipid-rich alpha-HDL but not with that of lipid-poor pre beta 1-LpA-I. Very low concentrations of alpha-HDL in plasmas of apoA-I(L141R)Pisa hemizygotes combined with reduced LCAT activity cause a decrease of the slow, unspecific, and LCAT-dependent components of cholesterol efflux into plasma.

Animals↗

Rod plateaux during dark adaptation in Sorsby's fundus dystrophy and vitamin A deficiency.

PURPOSE: To investigate the transitory plateaux observed during dark adaptation after partial bleaches in Sorsby's fundus dystrophy (SFD) and in systemic vitamin A deficiency (VAD). METHODS: Psychophysical dark adaptation functions were measured after bleaching exposures isomerizing from 2% to 99% of the rhodopsin. Narrow-band stimuli of 1.7 degrees diameter and 200 msec duration were presented at an eccentricity of 30 degrees. RESULTS: After a full bleach, the patients showed typical dark adaptation abnormalities reported for these diseases. The cone recovery was slowed, and the time to the rod-cone break was delayed; the final phase of rod recovery was also slowed but led to a normal final rod threshold. After partial bleaches, short wavelength stimuli produced a biphasic recovery function, with an initial rapid component and plateau, followed by a subsequent break-off and eventual return to prebleach thresholds. Action spectra obtained during the plateaux were consistent with thresholds for shorter wavelength stimuli mediated by rods and thresholds for longer wavelength stimuli mediated by cones. In the patient with VAD, vitamin A supplementation led to accelerated recovery and disappearance of the transitory rod plateaux. CONCLUSIONS: The biphasic dark adaptation functions resulting from fractional bleaches in SFD and VAD appear superficially similar to the classic biphasic adaptation functions obtained with full bleaches. However, thresholds during the plateaux are lower than the cone threshold, and action spectra indicate rod mediation. These transitory rod plateaux may increase our understanding of the normal visual cycle and its perturbation in retinal disease.

Adult↗

Effects of dobutamine, epinephrine and norepinephrine on the hemodynamics of dogs during hemorrhagic shock.

BACKGROUND: The present study examined how effective epinephrine (EPI), norepinephrine (NOR) and dobutamine (DOB) were for resuscitating dogs subjected to hemorrhagic shock (HS). METHODS: Dogs (n = 42) were randomly assigned to seven test groups: EPI, NOR and DOB infusion with and without HS, and HS dogs with no catecholamine. Following baseline measurements, the dogs were bled to a mean arterial blood pressure of 40 mmHg. After 3 h, the shed blood was reinfused. EPI and NOR (0.1, 0.4 and 1.6 micrograms/kg/min) and DOB (2.5, 5.0 and 10.0 micrograms/kg/min) were given and the dog allowed to stabilize for 30 min. Hemodynamic and blood gas data were obtained at 6 time points (control, shock, resuscitation and after catecholamine infusion). RESULTS: There was no significant difference in myocardial performance (dP/dt) between the respective shocked and unshocked groups after blood resuscitation. In dogs without catecholamine infusion, CO and SvO2 continued to decline whereas SVR increased. DOB (2.5 to 10.0 micrograms/kg/min) with and without shock improved CO, LV dP/dt, SVR and SvO2. EPI did not further improve CO or SvO2 at infusion rates above 0.1 microgram/kg/min (with and without shock). NOR did not improve SvO2 at any infusion rate (with and without shock) and did not improve CO until the infusion rate was at 0.4 microgram/kg/min (without shock). CONCLUSIONS: This study advocates the use of both volume replacement therapy and DOB for resuscitation of HS dogs.

Animals↗

Disease expression in X-linked retinitis pigmentosa caused by a putative null mutation in the RPGR gene.

PURPOSE: To determine the disease expression in X-linked retinitis pigmentosa (XLRP) caused by a putative null mutation in the RPGR (retinitis pigmentosa GTPase regulator) gene. METHODS: In a family with XLRP, haplotype analysis was performed with polymorphic microsatellite markers from the Xp chromosomal region, and genomic polymerase chain reaction sequencing was used to identify sequence variations in the RPGR gene. Hemizygotes and heterozygotes were evaluated clinically and with visual function tests. Optical coherence tomography (OCT) was performed on heterozygotes. Postmortem donor retinas from a heterozygote were examined by microscopy and immunocytochemistry. RESULTS: X-linked inheritance was confirmed by haplotype analysis using Xp markers. Sequence analysis of the RPGR gene identified a single base pair change, a G-->T transversion, that converts codon 52 GGA (Gly) to TGA (stop codon); the mutation segregates with the disease. A hemizygote in the third decade of life had barely measurable rod function and severely impaired cone function that diminished further over a 7-year interval. Heterozygotes varied in degree of disease expression from mild to severe. Perimetry showed loci with normal rod and cone sensitivity interspersed with loci having either equal rod and cone dysfunction or rod > cone dysfunction. Electroretinographic photoreceptor responses had equal reductions in rod and cone maximal amplitude. OCT cross sectional reflectance images of retinal regions with severe dysfunction showed reduced thickness of the retina and retinal pigment epithelium-choriocapillaris (RPE-CC) complex and increased reflections posteriorly. Regions with mild dysfunction showed similar OCT findings but with preserved retinal thickness. Retinal histopathology in a heterozygote revealed loss of photoreceptors throughout, with retention of only a few islands of cones with tiny or absent outer segments and rods lacking outer segments. CONCLUSIONS: This RPGR gene mutation, in its mildest expression in heterozygotes, causes a relatively equal disturbance of rod and cone photoreceptor function. Detectable structural change by OCT at the level of the RPE-CC can be present in patches of retina with minimal functional disturbance. More advanced disease stages in heterozygotes show greater rod than cone dysfunction, and the end stage in hemizygotes and heterozygotes is that of typical RP, with only barely detectable cone function from residual cones in a thinned retina with abnormal RPE and choriocapillaris.

Adult↗

Characterization of the acetylcholinesterase gene from insecticide-resistant houseflies (Musca domestica).

Acetylcholinesterase (AChE) is the target site for the organophosphates and carbamates in insects. Widespread use of these two classes of insecticides has led to the selection of resistance. Target modification was regarded as a molecular mechanism in some resistance species. The altered AChEs with reduced sensitivity to inhibition are related to this resistance. AChE genes from two insecticide-resistant housefly (Musca domestica) strains D3 and Kash were isolated and sequenced using RT-PCR and streptavidin-linked magnetic bead techniques. The cDNAs have a 2082-bp open reading frame from which the complete amino acid sequence of AChE has been deduced. Some differences in nucleotide sequence and four-point mutations of amino acid were found compared to a susceptible strain, i.e., the Cooper strain. Three substitutions are likely to confer insecticide insensitivity, which seems that D3 and Kash belong to CH2 pattern of resistance.

Acetylcholinesterase↗

The evaluation of intra- and extra-cranial circulation in subclavian steal syndrome.

OBJECTIVE: To compare the efficacy of transcranial Doppler ultrasound (TCD) and digital subtraction angiography (DSA) in identifying the clinical and hemodynamic relationship between intra- and extra-cranial circulation and subclavian steal syndrome. METHODS: Sixteen patients were collected. The intra- and extra-cranial arteries were insonated with Doppler ultrasound. DSA and brain CT were performed in all patients. The relationship between the grade of arterial stenosis showing in DSA and the flow direction showing in TCD was studied. RESULTS: TCD showed reversal flow of the vertebrobasilar artery in 13 patients, normal flow in 3, which was influenced obviously by fist-clenching. In the hyperemia test, the flow velocity and the direction changed significantly in all patients. The steal phenomenon of the middle cerebral artery (MCA) was coincident with that of the arterial cerebral artery (ACA) in 2 cases. Stenosis of MCA or ACA was found in 5 cases (31%). Nine patients were treated with arterial bypass or angioplasty. TCD was performed during the follow-up. CONCLUSIONS: Reversal flow of the vertebral artery may occur in rest or only in exercise, depending on the grade of subclavian arterial stenosis. Hyperemia test is the most sensitive index. It is necessary to monitor blood flow in the MCA and basilar artery in hyperemia test. The coexistence of intra- and extra-cranial arterial stenosis is common.

Adult↗