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Biomedical subjects

M Cheng

Publications and source records attributed to M Cheng.

At least 73 records · Page 4Linked to original sources
PubMed1995

A case-control study of the etiology of laryngeal cancer in Liaoning Province.

A case-control study of laryngeal cancer was conducted in Liaoning Province between January 1991 and April 1992 among 100 subjects with newly diagnosed cancer and 100 controls. The results of one factor analysis, odd ratio (OR), and conditional logistic regression indicated that smoking was the first significant risk factor for laryngeal cancer with an OR value of 16.8. Tobacco smoking ranked the first with an OR value of 30.4. Other factors such as alcoholic indulgence, insufficient intake of vegetable and fruits in winter and spring, air pollution in room and working environment, and fatigue of vocal cords were closely associated with the occurrence of laryngeal cancer.

Carcinoma, Squamous Cell↗
PubMed1995

[The reconstruction of facial burn and deformity from burn scar].

Thirty-seven patients with facial full-deep burn and burn scar contructure were treated in our department. The operation included transplantation, of whole piece of full thickness skin (3 patients), transplantation of whole piece of full thickness skin with subdermal vascular rete a (1), transplantation of improved whole piece of full thickness skin (26), and separated transplantation of large piece of partial thickness skin (7). Follow-up from 3 to 15 years showed that the facial skin of whole piece of full thickness skin was soft, smooth, and had natural facial expression. The facial skin of separated transplantation had slight scar and pigmentation. The improved whole piece of full thickness skin was recommendable for avoiding the secondary ectropion of eyelid and lip.

Adolescent↗
PubMed1995

Menses cup evaluation study.

OBJECTIVE: To determine whether the menses cup is well tolerated by menstruating women. DESIGN: Prospective descriptive clinical study. SETTING: Normal human volunteers in an academic research environment. PARTICIPANTS: Fifty-one menstruating women recruited between June to December 1991. INTERVENTIONS: Each participant was provided with two menses cups and an instruction sheet. Baseline information, including age, occupation, martial status, parity, description of menstrual flow, and current method used to cope with menstrual flow was collected. Subjects were asked to describe their experience with the cup at 1-, 2-, 6-, and 12-month intervals. MAIN OUTCOME MEASURE: The proportion of women who found the cup acceptable. RESULTS: The cup was used by 51 subjects for a total of 159 cycles. Overall, 23 women (45%) found the cup an acceptable method for coping with menses. Among 29 (57%) women who used the cup for two or more cycles, 62% found it acceptable. CONCLUSION: The menses cup may be an acceptable method for some women for coping with menstrual flow.

Equipment and Supplies↗
PubMed1994

[An analysis of HCV infection by using recombinant HCV antigen C11 and C7].

The recombinant protein C11 derived from the C region of HCV genome and C7 derived from the nonstructural region NS3 of the HCV genome were used in ELISA to study 442 cases of liver diseases, including chronic hepatitis, cirrhosis and hepatocellular carcinoma in Beijing District. It was found that HBV infection was more prevalent than HCV infection in this district. Both liver cirrhosis and hepatocellular carcinoma were more related to the superinfection of HBV and HCV rather than HBV infection alone or HCV infection alone. It is suggested that there may be some interaction between the HBV and HCV to worsen the prognosis of these patients.

Antigens, Viral↗
PubMed1994

The mitogen-activated protein kinases, ERK1 and ERK2.

The MAP kinases are ubiquitous enzymes that are activated in a complex fashion and inactivated by multiple phosphatases including a dedicated dual specificity enzyme. These kinases have a diverse array of substrates with important functions that result in their substantial regulatory impact. The ERK/MAP kinase cascade displays not only downstream but also upstream interactions as well as cross talk with other signaling pathways which fine tunes the cascade in a cell type-specific fashion. Transforming agents utilize this cascade in inducing cell proliferation.

Animals↗
PubMed1994

[Childhood passive smoking and purulent meningitis].

The relationship between purulent meningitis and passive smoking were investigated in 63 children with purulent meningitis aged 1-12 years against 63 children with non-purulent meningitis as control. It was found that the odds ratio of purulent meningitis for children receiving passive smoking was 3.0, and the 95% confident limit was greater than 1 (P < 0.05). There was significant dose-effect relationship between the daily dosage of cigarette smoked by family members and the odds ratio of purulent meningitis (P < 0.005). It suggests that passive smoking is one of the risk factors for purulent meningitis.

Case-Control Studies↗
PubMed1994

[Determination of norfloxacin, an active dissociation product of silver norfloxacin, in guinea pig plasma and tissue by high performance liquid chromatography with column-switching].

A column switching HPLC method was established for the determination of norfloxacin, and active dissociation product of silver norfloxacin, in guinea pig plasma and tissues. The pre-treating column (50 mm x 5 mm ID) and analytical column (150 mm x 5 mm ID) were packed with mu-Bondapak C18, 37-50 microns and YWG-C18, 10 microns, respectively. A mixture of CH3OH-0.008 mol/L phosphate buffer-0.05 mol/L tetrabutylammoniun bromide (25:75:4) was used as the analytical mobile phase with a flow rate of 1 ml/min. The pre-treating mobile phase was 0.008 mol/L phosphate buffer with a flow rate of 3 ml/min. UV detection was made at 280 nm. The results were linear within a range of 2-128 micrograms/ml norfloxacin for plasma. The lowest detection limit was 0.25 microgram/ml for plasma. The mean recovery of the method was 102% with a relative standard deviation of less than 7%.

Administration, Topical↗
PubMed1993

Bridged gamma-carbolines and derivatives possessing selective and combined affinity for 5-HT2 and D2 receptors.

A series of 5,6,7,8,9,10-hexahydro-7,10-iminocyclohept[b]indoles and 6,7,8,9,10,11-hexahydro-7,11-imino-5H-cyclooct[b]indoles was prepared. Structural modifications of the lead compound, 11-[4-(4-fluorobenzoyl)propyl]-5,6,7,8,9,10-hexahydro-7,10- iminocyclohept[b]indole (5, Ki = 0.82 nM vs [3H]ketanserin) enabled the identification of the functionality necessary for high affinity at serotonin 5-HT2 and dopamine D2 receptors in ligand binding studies. The indole ring, as well as the benzoyl or isosteric benzisoxazole moiety, were essential for high affinity. Variations of the length of the side chains resulted in ligands having either selective affinity for the 5-HT2 receptor or a combination of 5-HT2 and D2 affinity. In vivo binding studies were performed on selected members in this series. The most potent member, 2-fluoro-11-[4-(4-fluorobenzoyl)butyl]-5,6,7,8,9,10-hexahydro-7,10- iminocyclohept[b]indole (36) had an ED50 of < 1 mg/kg at the 5-HT2 and D2 receptors following oral administration.

Animals↗
PubMed1993

A clinical assessment of desflurane anaesthesia and comparison with isoflurane.

In 48 randomly assigned ASA I adult patients undergoing elective orthopaedic procedures, we compared the pharmacodynamics of desflurane (DF) and isoflurane (IF), and their pharmacokinetics during rapid induction of deep anaesthesia (via face mask, to 1.5-2 MAC, after thiopentone), maintenance of anaesthesia at 1.25 MAC, and emergence therefrom. During induction, laryngeal reactions ranging from mild crowing to laryngospasm occurred more frequently with DF than with IF (15/24 DF, 5/24 IF; P < 0.05) and was more severe (9/24 DF, 1/24 IF, excluding the mildest form, P < 0.05). As a result, induction of anaesthesia was not accomplished faster with DF, in spite of a faster equilibration between exhaled and inhaled concentrations. Emergence from DF was more rapid and less complicated by delirium. Pharmacokinetically, the exhaled concentration of DF reached 90% of the inhaled concentration within five minutes of induction, whereas that of IF lagged behind and remained 25% below the inhaled concentration (1 vs 1.34 +/- 0.05) even one hour after induction. Premature ventricular contractions did not occur in any patient even during periods of difficulty with the airway and oxygen desaturation. It is concluded that DF is a safe anaesthetic, pharmacokinetically superior to IF but clinically inferior for induction of anaesthesia via a face mask. Because of the fast equilibration, the exhaled concentration of DF can be controlled more precisely by the dial setting of the vaporiser.

Adolescent↗
PubMed1993

Regulation and properties of extracellular signal-regulated protein kinases 1, 2, and 3.

The extracellular signal-regulated kinases ERK1 and ERK2 are 43- and 41-kd enzymes activated by many extracellular cues. They lie within a protein kinase cascade that is used to achieve many cellular responses. In addition to the wide variety of regulatory contexts in which they are activated, they phosphorylate important regulatory proteins, including receptors, transcription factors, cytoskeletal proteins, and other protein kinases. Thus, the stimulation of this kinase cascade is thought to have a pleiotropic action. ERK1 and ERK2 are controlled by phosphorylation on threonine and tyrosine. To understand the regulatory mechanisms, wild-type and mutant ERKs were expressed in bacteria and phosphorylated with MEK, the enzyme that is upstream of ERKs. Wild-type proteins could be activated 500- to 1,000-fold in vitro by MEK. ERK3, an enzyme of 62 kd and only 50% identical to ERK1 and ERK2 in the catalytic core, was also phosphorylated by MEK in vitro. This suggests that all three of these enzymes are targets of common signaling pathways.

Animals↗
PubMed1993

Breech delivery at term: a critical review of the literature.

OBJECTIVE: To determine whether planned vaginal or elective cesarean delivery is better for singleton term breech infants. DATA SOURCES: Articles that included singleton term pregnancies with breech presentation published in English between 1966 and September 1992 were searched through the Index Medicus, Oxford Database of Perinatal Trials, and MEDLINE. METHODS OF STUDY SELECTION: We reviewed 24 studies that presented results according to the intended mode of delivery in terms of the following adverse outcomes: perinatal mortality, low 5-minute Apgar score, traumatic neonatal morbidity, overall short-term neonatal morbidity, long-term infant morbidity, and maternal morbidity and mortality. DATA EXTRACTION AND SYNTHESIS: The effect of planned vaginal delivery, compared with planned cesarean delivery, for each adverse outcome was determined by calculating a typical odds ratio. Perinatal mortality was higher for the planned vaginal delivery groups than for the elective cesarean groups, with a typical odds ratio of 3.86 (95% confidence interval [CI] 2.22-6.69). Neonatal morbidity due to trauma was also higher for the planned vaginal delivery groups, with a typical odds ratio of 3.96 (95% CI 2.76-5.67). CONCLUSION: The results suggest that planned vaginal delivery may be associated with higher perinatal mortality and morbidity rates than planned cesarean delivery. Because of selection bias in the majority of studies, differences in outcomes may be due to factors other than the planned method of delivery. An appropriately sized, randomized controlled trial is needed to answer this question definitively.

Breech Presentation↗