Biomedical subjects

K Ji

Publications and source records attributed to K Ji.

4 recordsLinked to original sources

PubMed2000

[Remodeling and biomechanical properties of thoracic aorta in spontaneously hypertensive rats].

Morphometry and microstructure of thoracic aorta of spontaneously hypertensive rats (SHR) at different periods before and after hypertension were studied quantitatively by histological method and computer image analysis. We also observed the changes of opening angle in the zero-stress state and the relationship between pressure and diameter in SHR during established hypertension. The results showed that with blood pressure chronically increasing, there was a significant increase in morphometric parameters and microstructure parameters of the thoracic aorta in SHR. The zero-stress state of opening angle in SHR during established hypertension increased significantly. These reults suggest that aortic structural remodeling in hypertension such as thickness of vascular wall and disproportional increase of collagen may lead to decrease in distensibility of the aorta in SHR. The structural remodeling and changes of mechanical properties in aorta may contribute to the important pathophysiology of hypertension-induced complications.

Animals↗

PubMed2000

[Zero-stress state of renal artery in spontaneously hypertensive rats].

By observing the opening angle of the renal artery, the zero-stress state of the renal artery was studied in spontaneously hypertensive rats (SHR) prior to and posterior to their hypertension, and the role of endogenous angiotensin II (Ang II) and endothelin (ET) on the zero-stress state was studied by giving SHR Losartan(AT1 receptor antagonist of Ang II) and BMS-182874 (an A type receptor antagonist of ET) respectively. The opening angle of the renal artery in SHR with established hypertension was much greater than that in wistar-Kyoto rats(WKY) (114.2 +/- 42.2 vs 70.2 +/- 30.4, P < 0.01). The opening angles of the renal artery in SHR treated with Losartan and BMS-182874 were much smaller than those in control SHR. The opening angles of the renal artery in Losartan-treated and BMS-182874-treated SHR were 65.9 +/- 32.7 and 66.6 +/- 41.54 respectively. The results suggest that non-unequal growth exists in the renal arterial wall in SHR with established hypertension and the residual stress and strain in SHR are greater than those in age-matched WKY. Endogenous Ang II and ET may play a role in the changes of zero-stress state in SHR with hypertension.

Angiotensin II↗

PubMed1998

[Sequencing and analysis of the NS5 region of HGV/GBV-C gene].

To study the genomic organization of non structural region 5 of HGV in China, 186 nucleotides of NS5 region of HGV were amplified, cloned and sequenced. The data were analyzed with computer programs. The results indicated that the gene sequence homology between 2 HGV isolates in this study was 95.2%. The comparison of these 2 isolates and 3 foreign isolates reported previously showed that the sequence homology was in the range of 84.4% to 92.4%, and was obvious by divergent from the foreign isolates. The results make us consider that HGV may have different genotypes, after a further inspection into the gene sequence of each region of HGV. The 2 isolates were from the sera collected in 1984, therefore the existence of HGV infection in Harbin was retrospectively traced to 1980s.

Base Sequence↗

PubMed1994

Computerized case-based instructional system for computed tomography and magnetic resonance imaging of brain tumors.

RATIONALE AND OBJECTIVES: A computerized system that applies the case-based approach to training radiologists to diagnose brain tumors was designed. The authors attempted to provide residents a tool that supports their visual memory and inducts case-based reasoning. METHODS: A relational database with a digital image library was implemented and incorporated into a computer aided instruction environment based on case presentation. An indexing system was structured around case features (case history and radiologic findings). "If-then" type rules were used to control the search direction within the case library and to generate lists of diagnostic hypotheses. The indexing system was evaluated against cases "known" to the system. RESULTS: The current case library consists of 122 cases with 640 digitized images (computed tomography and magnetic resonance imaging). The accuracy of retrieval for "known" to the system cases was 80.7%. CONCLUSIONS: A case library stored on a personal computer can be efficiently searched for a combination of radiologic findings and can offer quality images for comparison to the case in question. A case library is a source of the information that may be used by different teaching applications.

Brain Neoplasms↗