Inactivation of farnesyltransferase and geranylgeranyltransferase I by caspase-3: cleavage of the common alpha subunit during apoptosis.

Caspase plays an important role in apoptosis. We report here that farnesyltransferase/geranylgeranyltransferase (FTase/GGTase)-alpha, a common subunit of FTase (alpha/beta(FTase)) and GGTase I (alpha/beta(GGTase)), was cleaved by caspase-3 during apoptosis. FTase/GGTase-alpha (49 kDa) was cleaved to 35 kDa (p35) in the Rat-2/H-ras, W4 and Rat-1 cells treated with FTase inhibitor (LB42708), anti-Fas antibody and etoposide, respectively. This cleavage was inhibited by caspase-inhibitors (YVAD-cmk, DEVD-cho). Serial N-terminal deletions and site-directed mutagenesis showed that Asp59 of FTase/GGTase-alpha was cleaved by caspase-3. The common FTase/GGTase-alpha subunit, but not the beta subunits, of the FTase or GGTase I protein complexes purified from baculovirus-infected SF-9 cells was cleaved to be inactivated by purified caspase-3. In contrast, FTase mutant protein complex [(D(59)A)alpha/beta(FTase)] was resistant to caspase-3. Expression of either the cleavage product (60-379) or anti-sense of FTase/GGTase-alpha induced cell death in Rat-2/H-ras cells. Furthermore, expression of (D(59)A)FTase/GGTase-alpha mutant significantly desensitized cells to etoposide-induced death. Taken together, we suggest that cleavage of prenyltransferase by caspase contributes to the progression of apoptosis.

Ether fraction of methanol extracts of Gastrodia elata, a traditional medicinal herb, protects against kainic acid-induced neuronal damage in the mouse hippocampus.

Gastrodia elata (GE) has been used traditionally for the treatment of convulsive diseases such as epilepsy in oriental countries including South Korea and still occupies an important place in traditional medicine in Asia. We studied the anticonvulsive effect and protective effect of the ether fraction of methanol extracts (EFME) of GE against hippocampal neuronal damage after kainic acid administration in mice. Mice were treated with the EFME of GE (200 or 500 mg/kg per day, p.o.) for 14 days before kainic acid injection (45 mg/kg, i.p.). The EFME of GE (at the dose of 500 mg/kg) delayed the onset time of neurobehavioral change (P<0.01) and reduced the severity of convulsions (P<0.05) and hippocampal neuronal damage in the CA1 (P<0.01) and CA3 (P<0.05) regions. Our results show that The EFME of GE has anticonvulsive effect and putative neuroprotective effect against excitotoxicity induced by kainic acid.

Kinetic study of oxalic acid inhibition on enzymatic browning.

Oxalic acid has a strong antibrowning activity. The inhibitory pattern on catechol-PPO model system appeared to be competitive, with a K(i) value of 2.0 mM. When the PPO was incubated with oxalic acid, the activity was not recovered via dialysis, but the inactivated enzyme partially recovered its activity when cupric ion was added. Comparing the relative antibrowning effectiveness of oxalic acid with other common antibrowning agents, oxalic acid with I(50) value of 1.1 mM is as effective as kojic acid and more potent than cysteine and glutathione.

Primary tubercolous osteomyelitis of the sternum.

We present an 82-year-old woman with anterior sternal pain diagnosed as primary mycobacterial osteomyelitis of the sternum. She was treated with simultaneous wide resection and reconstruction of the chest wall. On admission, computed tomographic scan showed a sclerotic sternal mass with soft tissue reaction. Mycobacterium tuberculosis was grown in initial culture. First-line antituberculous medication and local debridement failed. The successful result was achieved by extensive sternal and chondral resection followed by simultaneous bilateral pectoralis major muscle flap positioning.

Tissue engineered tracheal prosthesis with acceleratedly cultured homologous chondrocytes as an alternative of tracheal reconstruction.

BACKGROUND: Autologous tissue is an ideal substitue for an extensive tracheal reconstruction, but it is rarely feasible in clinical situations. Many tracheal prosthesis had been used for such an instances, but unfortunately it is still problematic. Dislocation, local infection, hemorrage, and luminal stenosis can cause prosthetic failure. To achieve clinically available autologous tracheal prosthesis, it is necessary that we have to get phenotypically functioning chondrocytes, rapid differentiation of harvested autologous chondrocytes, and the survival of free grafted cultured chondrocytes. METHODS: In this study, we investigated isolation and culture method of the chondrocytes using the rabbit costal cartilage, and the cells were characterized microscopically and biochemically first. Then we have used cultured rabbit chondrocytes to investigate the role of growth factors upon the proliferation and regulation of the cultured chondrocytes. We have examined the effect of peptide growth factors on DNA and proteoglycan synthesis to the rabbit chondrocyte. The effects of IGF-I and basic FGF were investigated individually. Secondly, acceleratedly cultured chondrocytes were embeded to polymer (PLGA) scaffold in bioreactor, and implanted to defected rabbit trachea. Six weeks later, the rabbits were sacrificed and examined their histologic characteristics. RESULTS: The harvested chondrocytes from costal arch grew well and were amplified successfully maitaining their own phenotypes. Its embedding to PLGA scaffold was accomplished successfully. The implanted tracheal prosthesis maintains its physical integrity well, but the histologic examination revealed non-viable chondrocytes. The epithelial linings were good. CONCLUSIONS: The tissue engineered tracheal prosthesis can be a promising alternative of good functional air way tube in short term experiment, but biologically not vital yet. Further investigations are necessary to see the survival of free grafted chondrocytes and the long term results.

Measurement of superoxide dismutase-like activity of natural antioxidants.

The superoxide dismutase (SOD)-like activity of natural antioxidants was evaluated by measuring the inhibition of pyrogallol autoxidation that is catalyzed by the superoxide radical. Among 22 water-soluble antioxidants tested, L-ascrobic acid, L-ascorbic acid 6-palmitate, glutathione (reduced form), (+)-catechin, and (-)-epicatechin showed effective SOD-like activity. To analyze lipophilic antioxidants, an optically clear organic system composed of diethyl ether, surfactant (dioctyl sulfosuccinate, AOT) and water, called reverse micelles, was developed. The optimum concentrations of AOT, water and pyrogallol for determining SOD-like activity were found to be 50 mM, 1.3 M, and 40 mM, respectively. After proving that pyrogallol autoxidation was mediated by the superoxide anion in that system, the SOD-like activity of 24 lipophilic antioxidants was measured. Cinnamon oil, gamma-oryzanol, extract of rosemary leaf, L-alpha-lecithin, and L-alpha-cephalin exhibited activity, although the activity of some antioxidants could not be measured because of the intense color or low solubility.

A glycosidase antibody elicited against a chair-like transition state analog by in vitro immunization.

Antibodies were generated against the positively charged chair-like glycosidase inhibitor nojirimycin by in vitro immunization. A number of catalytic antibodies were isolated, one of which catalyzes the hydrolysis of p-nitrophenyl beta-D-glucopyranoside 3 with a rate enhancement (kcat/kuncat) of 10(5) M over the HOAC-catalyzed reaction. The antibody discriminates modifications in the pyranoside ring of substrate 3 at the C2, C4, and the anomeric positions. The pH dependence of the reaction and chemical modification studies suggest the presence of an active-site Asp or Glu residue that may function as a general acid. This study further defines those requirements necessary to generate antibodies that efficiently cleave glycosidic bonds.