PubMed HealthSearch

Biomedical subjects

M X Huang

Publications and source records attributed to M X Huang.

At least 19 recordsLinked to original sources

[A matched case-control study on the relations between beta-carotene and lung cancer].

In order to discover the relationship between dietary nutrients intake and risk of lung cancer 1:1 matched case-control study on 156 recent histologiclly diagnosed primary lung cancer patients and 156 patients with respiratory tumour and other related diseases as controls, was conducted in Wuhan. All cases and controls were asked to participate in the nutritional assessment program and a food frequency questionnaire containing 64 food items was filled in. The findings showed that there was a statistically significant difference between dietary intake of beta-carotene between the two groups (2877.13 +/- 393.43 vs. 3445 +/- 430.98 micrograms/day). Having controled the confounding factor of cigarette smoking, a significant linear trend for lower dietary carotene intake toward higher lung cancer risk was observed.

Adenocarcinoma

[Clinical and pathological studies of malignant fibrous histiocytoma (MFH) in the oral and maxillofacial regions with report of 15 cases].

This paper reports 5 patients with MFH in the soft tissues and 10 in the jaws. Fourteen patients (5 in soft tissues and 9 in jaws) underwent surgery, 5 and 3 of the 9 bone cases received additional irradiation and chemotherapy respectively. Fourteen patients had been followed up for 6 months to 4 and 1/2 years. Two patients of jaw had local recurrences 1 to 8 months following surgery; 6 of 9 ones with follow-up died, 2 of whom were associated with pulmonary metastases. MFH of bone showed significantly worse prognosis than those localized in soft tissues, particularly in maxilla. Pathologically, the tumors of this series were divided into 5 types. The relation between the mitosis and the malignancy of MFH in the jaws was significant. Immunohistochemical stains for lysozyme, A, AT and ACT showed that ACT was the most sensitive marker for MFH.

Adolescent

Adenosine triphosphate liposomes: encapsulation and distribution studies.

Four methods for encapsulating adenosine triphosphate (ATP) in liposomes were evaluated. Optimum entrapment required emulsifying ATP with the lipids used to form the liposome membrane in a high-speed homogenizer followed by evaporating the organic solvent with vigorous stirring. Under these optimum conditions ATP entrapment was 38.9%; i.e., the dosage form contained 38.9 g of ATP per 100 g of lipid. The distribution of positively charged liposomes loaded with ATP was studied in dogs with experimentally induced myocardial infarction. Intravenous injection of positively charged ATP liposomes caused accumulation of ATP in myocardial infarct tissue. Myocardial infarct tissue has reduced blood flow; since positively charged liposomes accumulated in infarct tissue, liposomes may be a drug delivery system for this disease state.

Adenosine Triphosphate

Compositional analysis of the three main gangliosides from adult human myometrium by a rapid capillary gas chromatographic method.

A new capillary GC method is described for the compositional analysis of the three main gangliosides isolated from adult human myometrium. The sample was subjected to methanolysis, acetylation and trimethylsilylation which allows all the constituents to be analyzed simultaneously. The predominant ganglioside was found to be GD3, with GM3 and GT1b the next most abundant.

Adult

A clinical investigation with Holter's monitoring of the antiarrhythmic effect of adonisidum.

The authors studied 24 cases of refractory premature beats by giving 0.1 adonisidum twice daily with Holter's monitoring. It was found that adonisidum was effective in 12 cases (P less than 0.001), or 50%. In another 8 patients adonisidum or mexiletine alone were ineffective for premature beats. However, when these patients were treated with both mexiletine and adonisidum, they responded with no exception (P less than 0.001). All 7 cases monitored with one hour Holter recording responded to adonisidum (P less than 0.001). As adonisidum tends to slow the heart rate, it is especially indicated for patients suffering from premature beats with increased heart rate, and should be used with caution in cases with slow heart rate or A-V block.

Adolescent

Effect of higenamine on action potential of ventricular myocardial cells.

Action potentials of isolated ventricular myocardial fibers of pigs and the electrophysiological actions of dl-demethylcoclaurine (DMC) or higenamine on the porcine myocardial cells were studied by glass microelectrodes. The action potentials of porcine ventricular myocardial fibers were similar to those of other mammalian hearts. Amplitude of the action potential was 115 +/- 9 mV, duration of action potential 242 +/- 30 ms, resting membrane potential -85 +/- 5 mV and the maximum rise of depolarization of action potential 151 +/- 27 V/s. After perfusion with normal Tyrode's solution containing DMC 5 micrograms/ml, the amplitude of action potential was increased and the duration of action potential was prolonged, the amplitude and duration of the plateau of action potential were increased and the slope of phase 2 of action potential was reduced (p less than 0.05). The resting potential, the slope of phase 3 and the maximum depolarization rate of phase 0 of action potential did not change. In Tyrode's solution containing Mn++ 3 mM, these electrophysiological actions of DMC disappeared. DMC may abolish the conduction block induced by K+-rich solution. In Tyrode's solution containing K+ 32 mM, the upstroke of action potential showed 2 phases under influence of DMC. The second phase disappeared when Mn++ was added. All findings indicate that DMC can be considered as an activator of the slow channel. The electrophysiological mechanism and clinical significance of DMC were discussed.

Alkaloids

Effect of higenamine on action potential of Purkinje and ventricular myocardial cells.

Action potentials of isolated Purkinje cells of dogs and the electrophysiological actions of higenamine on the dog's Purkinje cells were studied by glass microelectrodes. The actions of higenamine on the action potential of Purkinje cells were: (1) increase of amplitude of the plateau phase, (2) enhancement of repolarization of phase 3 and shortening of action potential duration (APD), (3) lower concentration of higenamine (10(-7) g/ml) causing shortening of APD without any significant change of the effective refractory period (ERP), and higher concentration (10(-6) g/ml) of it causing shortening of both APD and ERP, (4) higher concentration (10(-6) g/ml) of higenamine increasing the slope of phase 4, decreasing the threshold of depolarization, and increasing the automaticity of the Purkinje cells, (5) action of higenamine on the Purkinje cells only partially blocked by tetrodotoxin (TTX) and verapamil. The above facts suggest that: (1) higher concentration of higenamine may induce tachyarrhythmias, while lower concentration may prevent arrhythmias; (2) in low concentration of higenamine, there is a relative increase of ERP. Thus, higenamine seems to be safer than isoproterenol in the treatment of bradyarrhythmias.

Action Potentials