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Biomedical subjects

M Q Xu

Publications and source records attributed to M Q Xu.

43 records · Page 3Linked to original sources
PubMed1988

Structural conservation among three homologous introns of bacteriophage T4 and the group I introns of eukaryotes.

Three group I introns of bacteriophage T4 have been compared with respect to their sequence and structural properties. The introns include the td intervening sequence, as well as the two newly described introns in the nrdB and sunY genes of T4. The T4 introns are very closely related, containing phylogenetically conserved sequence elements that allow them to be folded into a core structure that is characteristic of eukaryotic group IA introns. Similarities extend outward to the exon sequences surrounding the three introns. All three introns contain open reading frames (ORFs). Although the intron ORFs are not homologous and occur at different positions, all three ORFs are looped-out of the structure models, with only the 3' ends of each of the ORFs extending into the secondary structure. This arrangement invites interesting speculations on the regulation of splicing by translation. The high degree of similarity between the T4 introns and the eukaryotic group I introns must reflect a common ancestry, resulting either from vertical acquisition of a primordial RNA element or from horizontal transfer.

Animals↗
PubMed1985

Hydatid disease of the lung.

A total of 1,022 patients with hydatid disease were treated by surgical operations in our hospital, 201 of whom had lung echinococcosis. The criteria for diagnosis were (1) a history of living in an area where hydatid disease prevailed and of contact with dogs or their contaminated environment; (2) pressure symptom in the lungs produced by larger hydatid cysts, concomitant infection that provoked pulmonary abscess, concomitant rupture into the bronchi with the abrupt onset of a barking cough, and rupture into the thoracic cavity causing acute pleural effusions; (3) positive results of Casoni's intradermal test as high as 82.3 percent; (4) typical roentgenoscopic findings, such as a round or ovoid shadow with a regular margin, definite limits, and uniform density that is unifocal or multifocal. Specific images described in this report may also be observed. Two procedures for treatment were adopted: for intact endocysts, a meticulous incision was made along the ectocyst wall and then the endocyst was extracted, and for endocysts that had previously lost fluid, puncture was used. After removal of the endocysts, appropriate suturing of bronchial fistulas and of residual loculi of the ectocysts in the lungs carried out to prevent infection.

Adolescent↗