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Biomedical subjects

C C Liang

Publications and source records attributed to C C Liang.

At least 55 records · Page 3Linked to original sources
PubMed1994

Influence of bulky side chains of amino acids on the solution conformation of peptide fragment (81-92) derivatives of CD4, TYICEVEDQKEE, as studied by NMR spectroscopy and molecular modeling.

Solution conformation of CD4 fragment 81-92 TYICEVEDQKEE and two of its benzylated analogues was determined by two-dimensional 1H NMR spectroscopy, distance geometry and simulated annealing techniques. The structures of both benzylated derivatives are similar but are distinct from that of wild-type dodecapeptide. It is concluded from structural analysis that bulky side chain(s) of amino acid(s) at an appropriate position can have a marked effect on the conformation and thus the functions of a peptide.

Amino Acid Sequence↗
PubMed1994

Conditional and unconditional automaticity: a dual-process model of effects of spatial stimulus-response correspondence.

Distributional analyses and event-related brain potential were used to show that effects of irrelevant spatial stimulus-response correspondence consist of 2 qualitatively different automatic components that can be distinguished on the basis of their dependencies on relative response speed and on computational requirements of the primary task. One component reflects priming of the spatially corresponding response by an abrupt stimulus onset that does not depend on the nature of the primary task. This unconditional component exhibits a biphasic pattern, with initial facilitation later turning into inhibition, analogous to that found for spatial cuing in visual detection tasks. The 2nd component reflects automatic generalization of task-defined transformations of relevant stimulus information to spatial codes; this conditional component does not depend on relative response speed. Possible connectionist implementations of the conditional mechanism are discussed.

Automatism↗
PubMed1994

The G gamma:A gamma ratios in the fetal hemoglobin of newborns of the Man ethnic group and their gamma-globin gene arrangements.

The G gamma:A gamma ratios of Hb F were determined in 331 newborn babies of the Man ethnic group in Liaoning Province, P.R. China, using polyacrylamide gel electrophoresis; in 27 cases they were also determined by reversed phase high performance liquid chromatography. The results showed that a high G gamma value (> 80%) was present in four cases (1.21%) and low G gamma values (30-48%) in six cases (1.81%); not a single case with the A gamma T [A gamma 75(E19)Ile->Thr] chain was found. Gene mapping analysis demonstrated that two babies with high G gamma values had the -G gamma-G gamma-/-G gamma-A gamma- (0.60%), and two others the -G gamma-AG gamma-A gamma-/-G gamma-A gamma- (0.60%) arrangements. Two of the four babies with low G gamma values were identified as -A gamma-A gamma-/-G gamma-A gamma- (0.60%) and the other two as -GA gamma-/-G gamma-A gamma- (0.60%). The genotype -A gamma-A gamma- has not been reported before in Chinese.

Asian People↗
PubMed1992

Cancer of the colon during pregnancy: report of a case and review of the literature.

A case of adenocarcinoma of the sigmoid colon during pregnancy is reported. The patient presented with anemia and a painless mass over the left abdomen without gastrointestinal discomfort, making this case different from 25 previously reported cases of colon carcinoma above the peritoneal reflection associated with pregnancy.

Adenocarcinoma↗
PubMed1992

Loop excision for cervical intraepithelial neoplasia.

We report the results of a prospective trial using a loop electrosurgical excision procedure (LEEP) on 97 patients with cervical intraepithelial neoplasia. In the LEEP group the mean cutting time and whole procedure time were 6.2 +/- 1.9 seconds and 12.7 +/- 3.5 minutes, respectively. The average blood loss was 3.6 +/- 1.9 mL. In the control group (39 cases) using laser conization, the mean cutting time and whole procedure time were 11.7 +/- 3.5 minutes and 44.9 +/- 8.9 minutes, respectively. The average blood loss in the control group was 11.2 +/- 3.1 mL. The differences between the two groups were statistically significant. During LEEP surgery, four cases had accidental vaginal excision. There were three cases of late cervical bleeding after surgery; the surface of the cervix was smooth, and no adhesion or crypt formation was noted after re-epithelialization. Eight patients became pregnant after the loop excision and no cervical incompetence was noted during antenatal care. After a one-year follow-up period in the colposcopy clinic, there was no recurrence of cervical intraepithelial neoplasia in either group. We advise that among the modalities of treatment for cervical intraepithelial neoplasia, LEEP appears to offer patients several benefits such as less bleeding, precise specimens, local anesthesia, less cost and less discomfort. It is particularly suitable for treating younger women who have not yet completed their families.

Adult↗
PubMed1990

Treatment of severe beta-thalassemia (patients) with myleran.

We previously reported that myleran, a cell cycle nonspecific drug, can stimulate gamma-globin gene expression in anemic adult rhesus monkeys. This finding prompted us to treat two patients with severe beta-thalassemia with myleran. Both patients received an initial course of therapy, constantly of myleran at a dosage of 0.2 mg/kg/d for 9 days followed by 0.15 mg/kg/d for the next 11 days. One patient received an additional 20-day course of myleran at a dosage of 0.2 mg/kg/d beginning 44 days after completion of the first course. No severe ill effects related to the drug were observed during or after drug administration. After 20 days of myleran treatment, levels of HbF and reticulocytes increased in both patients and level of F cells increased in patient 1. In patient 1, Hb concentration rose from 42g/L (9 days after transfusion) before treatment to a maximum of 65g/L afterward; in patient 2, it rose from 74g/L to a maximum of 106g/L. A value of 15g/L above baseline lasted for about 5 months in both patients. Hypomethylation of bone marrow DNA near the gamma-globin gene was demonstrated in patient 1.

Busulfan↗
PubMed1989

Appendicitis during pregnancy.

Twenty-four pregnant women with acute appendicitis received exploratory laparotomy during an 8-year period. Abdominal pain accompanied with nausea and vomiting were the most common symptoms. Abdominal tenderness and rebounding pain were the most reliable physical signs. Leukocytosis with WBC count greater than 15,000/cu mm and granulocytes greater than 87% and prolonged symptomatic duration were indications that appendiceal perforation might have occurred. A McBurney's incision and spinal anesthesia were preferred for appendectomy during pregnancy. In cases of uncomplicated appendicitis, tocolytic agents and antibiotics were not routinely used. Premature labor occurred in 21% of patients during postoperative period.

Adult↗
PubMed1989

Studies of beta-thalassemia mutations in families living in three provinces in southern China.

beta-Thalassemia is a common disease in Southern China and 10 different mutations or frameshifts are responsible for most types of beta-thalassemia in this area. We studied 126 chromosomes of 80 beta-thalassemia patients from the Guangxi, Guangdong, and Sichuan Provinces using the polymerase chain reaction followed by dot-blot hybridization with specific oligonucleotide probes. The most common mutation in the three provinces is the frameshift at codons 41-42, followed by the A----T mutation at codon 17. The A----G mutation at nt -29 of the promoter is common in Sichuan but not in the other two provinces. Three mutations (T----C at nt -30; G----T at IVS-I-1, and G----C at IVS-I-5) were not observed. These data were used to initiate a prenatal diagnosis program using the same techniques for identification. Eleven fetuses at risk for beta-thalassemia have been diagnosed.

Base Sequence↗
PubMed1985

Alpha-1-antitrypsin types in five Chinese national minorities.

The frequencies of alpha-1-antitrypsin alleles were determined for five Chinese national minorities: Uigur, Korean, Mongolian, Chuang, and Li. PI S and PI Z alleles are not found in the five populations studied. PI ETOK allele is present in Korean, Mongolian, and Chuang populations, and Etokyo is a very common alpha-1-antitrypsin variant in Chinese. Other alleles which occur in more than one of the minorities are PI X (Mongolian and Chuang) and PI M4 (Korean and Uigur). The high frequency of PI M4 in the Uigur population suggests a probably Occidental origin of this nationality.

Alleles↗
PubMed1985

Geographical variability of alpha-1-antitrypsin alleles in China: a study on six Chinese populations.

Alpha-1-antitrypsin phenotypes of six Chinese Han populations (20 degrees-45 degrees N. latitude) were determined. The frequency of allele M2 increases from North to South China. The north-south change of M2 appears to be mainly at the expense of alleles M1 and M3. Geographical variability of other variants was also observed. In the northern populations, the most common variants are M4 and Etokyo; in the southern populations, Pweishi, a variant which can not be distinguished electrophoretically from Pyasugi. These results form a distribution pattern of alpha-1-antitrypsin alleles in China.

Alleles↗