Reversal of Human Multi‐Drug Resistance Leukaemic Cells by Stemofoline Derivatives via Inhibition of P‐Glycoprotein Function

Our previous study reported multi‐drug resistance (MDR) reversing properties of synthetic stemofoline derivatives (STFD), OH‐A1, NH‐B6 and NH‐D6 on P‐glycoprotein (P‐gp) overexpressing leukaemic cells (K562/Adr); however, the mechanism was unclear. In this study, we further investigated whether the STFD reverse MDR through either the inhibition of P‐gp function or expression in K562/Adr cells, or both. The P‐gp functional studies showed that the STFD increased the accumulation of calcein‐AM, rhodamine 123 and [¹⁴C]‐doxorubicin in K562/Adr cells, while the effects have not been seen in their parental sensitive cancer cell line (K562). Further, the STFD did not alter the P‐gp expression as determined by Western blotting. This study concludes that the STFD reverse MDR via the inhibition of P‐gp function. The efficacy of the STFD to inhibit P‐gp function followed the order: NH‐B6 >  OH‐A1 >  NH‐D6. These compounds could be introduced as candidate molecules for treating cancers exhibiting P‐gp‐mediated MDR.     

Incomplete unilateral cleft of the primary palate: delayed secondary bone grafting combined with orthodontic treatment

The presence of a fissural lateral incisor in an alveolar cleft is not a common occurrence and, if one is present, must in most instances be removed because of microdontia or because it may compromise a bone graft. This case report presents an example of bone grafting carried out late in the secondary stage of the patient's dentition, in conjunction with retention of the fissural lateral incisor as requested by the patient, and shows an acceptable outcome from the points of view of both aesthetics and dento-alveolar health.     

在中国大学开展暑期课程--宋卡王子大学与云南中医学院联合教学实例

介绍了泰国宋卡王子大学与中国云南中医学院联合举办国际贸易（中国）专业的具体做法和经验。从2002年3月至2002年5月，59名泰国宋卡王子大学学生被送往云南中医学院学习两门汉语课程及中国文化，在云南中医学院学习所取得的学分将被转换为他们学习成绩的一部分。这是两校首次开展联合教学工作，合作既使双方从中受益，又增进了两校领导、教职工和学生之间的关系和友谊。     

Frequency of Y chromosome microdeletions and chromosomal abnormalities in infertile Thai men with oligozoospermia and azoospermia

Aim： To investigate the possible causes of oligozoospermia and azoospermia in infertile Thai men, and to find the frequencies of Y chromosome microdeletions and cytogenetic abnormalities in this group. Methods： From June 2003 to November 2005, 50 azoospermic and 80 oligozoospermic men were enrolled in the study. A detailed history was taken for each man, followed by general and genital examinations. Y chromosome microdeletions were detected by multiplex polymerase chain reaction （PCR） using 11 gene-specific primers that covered all three regions of the azoospermic factor （AZFa, AZFb and AZFc）. Fifty men with normal semen analysis were also studied. Karyotyping was done with the standard G- and Q-banding. Serum concentrations of follicle stimulating hormone （FSH）, luteinizing hormone （LH）, prolactin （PRL） and testosterone were measured by electrochemiluminescence immunoassays （ECLIA）. Results： Azoospermia and oligozoospermia could be explained by previous orchitis in 22.3%, former bilateral cryptorchidism in 19.2%, abnormal karyotypes in 4.6% and Y chromosome microdeletions in 3.8% of the subjects. The most frequent deletions were in the AZFc region （50%）, followed by AZFb （33%） and AZFbc （17%）. No significant difference was detected in hormonal profiles of infertile men, with or without microdeletions. Conclusion： The frequencies of Y chromosome microdeletions and cytogenetic abnormalities in oligozoospermic and azoospermic Thai men are comparable with similarly infertile men from other Asian and Western countries.     

Anti-P-glycoprotein conjugated nanoparticles for targeting drug delivery in cancer treatment

Targeting therapeutics to specific sites can enhance the efficacy of drugs, reduce required doses as well as unwanted side effects. In this work, using the advantages of the specific affinity of an immobilized antibody to membrane P-gp in two different nanoparticle formulations were thus developed for targeted drug delivery to multi-drug resistant cervical carcinoma (KB-V1) cells. Further, this was compared to the human drug sensitive cervical carcinoma cell line (KB-3-1) cells. The two nanoparticle preparations were: NP1, anti-P-gp conjugated with poly (DL-lactic-coglycolic acid) (PLGA) nanoparticle and polyethylene glycol (PEG); NP2, anti-P-gp conjugated to a modified poloxamer on PLGA nanoparticles. The cellular uptake capacity of nanoparticles was confirmed by fluorescent microscopy. Comparing with each counterpart core particles, there was a higher fluorescence intensity of the targeted nanoparticles in KBV1 cells compared to KB-3-1 cells suggesting that the targeted nanoparticles were internalized into KB-V1 cells to a greater extent than KB-3-1 cell. The results had confirmed the specificity and the potential of the developed targeted delivery system for overcoming multi-drug resistance induced by overexpression of P-gp on the cell membrane.     

Zinc finger protein designed to target 2-long terminal repeat junctions interferes with human immunodeficiency virus integration

Abstract Integration of the human immunodeficiency virus type 1 (HIV-1) genome into the host chromosome is a vital step in the HIV life cycle. The highly conserved cytosine-adenine (CA) dinucleotide sequence immediately upstream of the cleavage site is crucial for integrase (IN) activity. As this viral enzyme has an important role early in the HIV-1 replication cycle, interference with the IN substrate has become an attractive strategy for therapeutic intervention. We demonstrated that a designed zinc finger protein (ZFP) fused to green fluorescent protein (GFP) targets the 2-long terminal repeat (2-LTR) circle junctions of HIV-1 DNA with nanomolar affinity. We report now that 2LTRZFP-GFP stably transduced into 293T cells interfered with the expression of vesicular stomatitis virus glycoprotein (VSV-G)-pseudotyped lentiviral red fluorescent protein (RFP), as shown by the suppression of RFP expression. We also used a third-generation lentiviral vector and pCEP4 expression vector to deliver the 2LTRZFP-GFP transgene into human T-lymphocytic cells, and a stable cell line for long-term expression studies was selected for HIV-1 challenge. HIV-1 integration and replication were inhibited as measured by Alu-gag real-time PCR and p24 antigen assay. In addition, the molecular activity of 2LTRZFP-GFP was evaluated in peripheral blood mononuclear cells. The results were confirmed by Alu-gag real-time PCR for integration interference. We suggest that the expression of 2LTRZFP-GFP limited viral integration on intracellular immunization, and that it has potential for use in HIV gene therapy in the future.