Biomedical subjects

Jimmy B Y So

Publications and source records attributed to Jimmy B Y So.

3 recordsLinked to original sources

PubMed2003

Cloning of rat telomerase catalytic subunit functional domains, reconstitution of telomerase activity and enzymatic profile of pig and chicken tissues.

Telomerase is a ribonucleoprotein polymerase which adds TTAGGG repeats to telomeric ends. Recent studies reported the reverse transcription enzyme activity mostly from the catalytic subunit (TERT) of the enzyme complex. Both human telomerase catalytic subunit (hTERT) and mouse telomerase catalytic subunit (mTERT) had been previously cloned but not rat telomerase catalytic subunit rTERT. In this study, the rTERT functional domains were cloned and was found that its function resemble to mouse and human telomerase. In addition, chicken and pig telomerase activity profile were studied and its enzyme activity is related to its proliferation capability of individual tissues. However, its catalytic subunit does not like mouse, rat and human cases that the telomerase activity could not reconstituted by the in-vitro transfection of mTERT and hTERT cloned vectors. Here we demonstrated that rTERT is similar to mTERT and hTERT but not pig and chicken telomerase. Further studies are needed to verify the malignancy characteristics because nowadays artificial organs/tissues from these animals are used for the transplantation to human body.

Animals↗

PubMed2002

Laparoscopic appendectomy for perforated appendicitis.

Although laparoscopic appendectomy for uncomplicated appendicitis is feasible and safe, its application to perforated appendicitis is uncertain. A retrospective study of all patients with perforated appendicitis from 1992 to 1999 in a university hospital was performed. A series of 231 patients were diagnosed as having perforated appendicitis. Of these patients, 85 underwent laparoscopy (LA), among whom 40 (47%) required conversion to an open procedure. An open appendectomy (OA) was performed in 146 patients. The operating time was similar for the two groups. Return of fluid and solid diet intake were faster in LA than OA patients (p < 0.01). Postoperative infections including wound infections and abdominal abscesses occurred in 14% of patients in the laparoscopy group and in 26% of those with OA (p < 0.05). The surgeon's experience correlated with the conversion rate. Laparoscopic appendectomy is associated with a high conversion rate for perforated appendicitis. If successful, it offers patients faster recovery and less risk of infectious complications.

Adolescent↗

PubMedDate not supplied

Antisense telomerase induced cell growth inhibition, cell cycle arrest and telomerase activity down-regulation in gastric and colon cancer cells.

BACKGROUND: Antisense telomerase RNA (anti-hTR) coupled with 2',5'-linked tetraadenylate (2-5A) shows an inhibitory effect on cell growth and induces apoptosis in certain kinds of cancer. This experiment examined the anti-hTR effect on gastric and colorectal cancer cells. MATERIALS AND METHODS: Gastric cancer cells CRL-5822, CRL-5971 and colorectal cancer cells HTB-38, CCL-247 were treated with repeated doses of anti-hTR. Cell growth and cell cycle parameters were analysed. Telomerase activity was measured by TRAP assay. Control oligonucleotides and normal fibroblast were used as control. RESULTS: After two doses of anti-hTR, the cell viability for CRL-5822, CRL-5971, HTB-38 and CCL-247 cells was reduced to 15%, 12%, 37% and 37%, respectively. The DNA histogram showed cells arrested at the G2/M-phase and the sub-G1 peak found indicated that apoptosis had occurred. CONCLUSION: Anti-hTR demonstrated inhibition of cell growth and cell cycle arrest on gastric and colorectal cancer cells through a telomerase regulation pathway. Its specificity towards cancerous tissues but not normal tissues suggested a potential for anti-cancer therapy.

Adenine Nucleotides↗