Search PubMed⌕ Search

Biomedical subjects

J Qin

Publications and source records attributed to J Qin.

151 records · Page 9Linked to original sources
PubMed1991

[Hypocrellin A induced photodamage to the fluidity of human erythrocyte membranes and membranes of some phospholipid liposomes].

In this paper, the photodamage of Hypocrellin A to the fluidity of human erythrocyte membranes and some kinds of membranes of phospholipid liposomes was investigated by measuring the changes in fluorescence polarization of the membranes. The results showed that the photosensitization effect of HA caused the decrease of membrane fluidity of the phospholipid (DPPC, DPPC/DPPE, phospholipid of erythrocyte membranes) liposomes. The DPPC and DPPC/DPPE liposomes were more sensitive to the damage than the phospholipid liposomes of erythrocyte membranes. To human erythrocyte membranes, the photodamage effect of HA caused its fluidity first increased and then, with the increment of illumination time, decreased. To spectrin-depleted and trypsin-treated erythrocyte membranes, this kind of change in fluidity was inhibited. All of the results indicated that phospholipids and proteins play different roles in the photodamage of HA to the fluidity of membranes. Membrane proteins, especially spectrin, were the key factor involved in the changes of the fluidity.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1990

[NK cell activity and counts of T-lymphocyte subsets in pulmonary tuberculosis].

NK cell activity and counts of T lymphocyte subsets examined in 42 pulmonary tuberculosis cases and 32 sex- and age-matched healthy controls. The mean NK cell activity in patients (62.78 + 27.54) were significantly higher than that in healthy controls (39.39 + 12.01) While counts of CD4+T cells and CD3+T cells in patients (35.5 + 9.3, 51.5 + 9.4) were lower than that in controls (43.8 + 9.0, 65.6 + 11.1). The CD4+T cell/CD8+T cell ratio had no significant change both in patients and in controls. Nk cell activity increased with the progression of tuberculosis lesion in X-ray. Counts of T lymphocyte subsets were unrelated with the severity and the extent of the lesion radiologically.

Adult↗
PubMed1987

Toxin resistance and/or male fertility reversion is correlated with defined transcription changes in the 1.5 kb AvaI region of cmsT.

Reversion of T type cytoplasmic male sterility (cmsT) to fertility is correlated with sequence changes in a 1.5 kb AvaI fragment. This 1.5 kb AvaI fragment is composed of 5' flanking sequences of ATPase subunit 6, one complete open reading frame (ORF 13) and part of the another (ORF 25). The sequence of the 1.5 kb AvaI fragment was compared to the sequences of homologous regions in the N (male fertile) and T revertant V3 mitochondrial DNA. Sequences were found to diverge between ORF 13 and ORF 25 coding regions. To further characterize the transcription of these rearranged sequences, specific probes for ORF 13, ORF 25 and 5' flanking sequences of ATPase 6 were hybridized to Northern blots of N, cmsT and the T revertant V3 and V18 mtRNAs. Each revertant has a single ORF 25 homologous transcript in contrast to the multitranscript pattern in cmsT. ORF 13 homologous transcripts were not detected in either revertant cytoplasm. The loss of ORF 13 and/or altered ORF 25 transcription in the fertile revertants may be responsible for the male fertility and/or toxin resistance in these plants.

Base Sequence↗
PubMedDate not supplied

Evidence for the lack of mismatch-repair directed antirecombination during mouse meiosis.

Meiotic recombination was studied in DNA mismatch repair (MMR)-deficient mice using a strain carrying a Pms2 knockout mutation. Using single-sperm typing, recombination was analyzed over five intervals on four chromosomes in four Pms2 -/- animals. A total of 1936 meioses were studied and compared to 1848 meioses from three Pms2 +/+ controls. A smaller study was carried out on a single interval in each of two chromosomes in an MMR-deficient mouse homozygous for the Msh2 knockout mutation. A total of 792 meioses were examined in the Msh2 -/- and 880 meioses in the Msh2 +/+ animal. Recombination fractions were not significantly different in either of the MMR-deficient mouse strains when compared to MMR-proficient controls. Our results appear to conflict with mouse embryonic stem (ES) cell gene-targeting experiments where MMR plays a major role in determining the efficiency of homologous recombination between nonidentical sequences. A number of possibilities could explain the apparent lack of a significant effect on meiosis.

Adenosine Triphosphatases↗
PubMedDate not supplied

An electric model with time varying resistance for a pneumatic membrane blood pump.

To investigate the effects of an artificial heart and cardiac assist device on the cardiovascular system and determine the proper control method, an electrical model is an effective tool. An electric model with time varying resistance is proposed to represent a pneumatic membrane blood pump, by which the resistance of the valves in the pump is a function of time. The model is consistent over the whole cardiac cycle, and the important transitional processes between systole and diastole are considered. The calculated results based on this model are compared with the experimentally measured waveforms of the corresponding state-variables of a loaded pump, and the model parameters estimated using the least-squares criterion are compared with the measured physical values of corresponding functional parts. Results showed that this electric model is capable of representing a pneumatic membrane pump with quite satisfactory accuracy. They also showed that the transitional property of the valve resistance has a significant influence on the output characteristics of the pump.

Heart Valves↗
PubMedDate not supplied

Sternocleidomastoid pseudotumor of infants and congenital muscular torticollis: fine-structure research.

Fifty cases, 16 with sternocleidomastoid pseudotumor of infants (SCMPOI) and 34 with congenital muscular torticollis (CMT), were investigated by light and electron microscopy. The ultrastructure of the pseudotumor revealed that there were myoblasts, fibroblasts, myofibroblasts, and mesenchyme-like cells, which consisted of fibrous tissue and were regarded as fibroblasts only in the literature. The myoblasts showed the various stages of differentiation and degeneration. For those cases without mass, the collagen fibrils and fibrocytes were often arranged in tight parallel bundles in which some muscles showed normal structure and some with decreased myofibrillae. The mesenchyme-like cells and myoblasts found in the pseudotumor may be the key point to its pathologic characteristics.

Child↗