Impact of G₂ checkpoint defect on centromeric instability

Centromeric instability is characterized by dynamic formation of centromeric breaks, deletions, isochromosomes and translocations, which are commonly observed in cancer. So far, however, the mechanisms of centromeric instability in cancer cells are still poorly understood. In this study, we tested the hypothesis that G(2) checkpoint defect promotes centromeric instability. Our observations from multiple approaches consistently support this hypothesis. We found that overexpression of cyclin B1, one of the pivotal genes driving G(2) to M phase transition, impaired G(2) checkpoint and promoted the formation of centromeric aberrations in telomerase-immortalized cell lines. Conversely, centromeric instability in cancer cells was ameliorated through reinforcement of G(2) checkpoint by cyclin B1 knockdown. Remarkably, treatment with KU55933 for only 2.5 h, which abrogated G(2) checkpoint, was sufficient to produce centromeric aberrations. Moreover, centromeric aberrations constituted the major form of structural abnormalities in G(2) checkpoint-defective ataxia telangiectasia cells. Statistical analysis showed that the frequencies of centromeric aberrations in G(2) checkpoint-defective cells were always significantly overrepresented compared with random assumption. As there are multiple pathways leading to G(2) checkpoint defect, our finding offers a broad explanation for the common occurrence of centromeric aberrations in cancer cells.

Abstract 2460: Epstein-Barr virus infection confer stress-resistant property in immortalized nasopharyngeal epithelial cells

Epstein-Barr virus (EBV) infection has been postulated to be an early event involved in the pathogenesis of NPC. The lack of representative premalignant nasopharyngeal epithelial cell system for EBV infection has hampered research investigation into the regulation and involvement of EBV infection in NPC pathogenesis. We have compared the efficiency of EBV infection in nasopharyngeal epithelial cells with different biological properties including immortalized, primary and cancerous nasopharyngeal epithelial cells. EBV infection could be achieved in all the nasopharyngeal epithelial cells examined with variable infection rate. TGF-β effectively enhanced EBV infection into nasopharyngeal epithelial cells both in the immortalized and primary nasopharyngeal epithelial cells. Stable infection of EBV was achieved in a telomerase-immortalized nasopharyngeal epithelial cell line, NP460hTert. The expression pattern of EBV-encoded genes and biological properties of this EBV infected cell line upon long term propagation were monitored. The EBV-infected nasopharyngeal epithelial cells acquired anchorage independent growth in soft-agar and exhibited invasive growth properties upon prolonged propagation. A distinguish feature of this EBV-infected nasopharyngeal epithelial cell model was its enhanced ability to survive under growth factor and nutrient starvation. This was evidenced by the suppressed activation of apoptotic markers and sustained activation of pAkt of EBV-infected cells compared to control cells under nutrient starvation. Examination of cytokine profiles of EBV-infected NP460hTert cells to nutrient and growth factor deprivation revealed upregulation expression of MCP-1 and GRO-α. The establishment of a stable EBV infection model of premalignant nasopharyngeal epithelial cells will facilitate research investigation into the pathogenic role of EBV in NPC development.

Acknowlegement: The authors wish to acknowlege the funding support from the Research Grant Council (Hong Kong) and the Area of Excellence on Nasopharyangeal Carcinoma Research Center (Hong Kong).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2460.

The concepts of family doctor and factors affecting choice of family doctors among Hong Kong people

OBJECTIVES

To identify concepts including misconceptions among the community members regarding family doctors, and determine factors affecting decisions on which doctor to consult in different clinical scenarios.

DESIGN

Household telephone survey conducted between 4 and 13 September 2006.

SETTING

Hong Kong community.

PARTICIPANTS

Cantonese-speaking Hong Kong residents aged 18 years or more were targeted. Randomly selected participants were asked to complete a questionnaire, which was designed based on a literature search and subsequent focus group discussions.

RESULTS

Among the 1811 households with eligible subjects to survey, 1204 completed the questionnaire (response rate, 67%). More than 85% considered a family doctor to be the first doctor they wanted to see even if it was inconvenient. "Clearly knowing my physical conditions", "fast-acting and effective treatment", and "doctor with friendly and sincere attitude" were the three most important factors influencing the choice of a family doctor. When affected by flu-like symptoms, 65% would go to a private clinic, 20% to a general out-patient clinic, 6% to a designated clinic with staff approved by their respective medical insurance/medical benefit scheme, and 5% to a private hospital outpatient clinic. Among the latter two groups, 65% consulted the same doctor every time when they felt sick. More than 50% of those willing to have regular follow-up by a family doctor for hypertension and diabetes paid more than HK$300 per month. Approximately 64% might consider having regular follow-up at a general out-patient clinic by a nurse specialist.

CONCLUSION

Hong Kong inhabitants already have their own ideas regarding how to care for their own health, and what kind of family doctors they prefer. This survey should help both doctors and health care policy makers to realign their current thinking, and thus provide a platform for the development of a primary care model unique to Hong Kong.

Molecular mechanisms for the release of chemokines from human leukemic mast cell line (HMC)-1 cells activated by SCF and TNF-alpha: roles of ERK, p38 MAPK, and NF-kappaB

BACKGROUND

Mast cells play pivotal roles in IgE-mediated airway inflammation and other mast cell-mediated inflammation by activation and chemoattraction of inflammatory cells.

OBJECTIVE

We investigated the intracellular signaling mechanisms regulating chemokine release from human mast cell line-1 (HMC-1) cells activated by stem cell factor (SCF) or tumor necrosis factor (TNF)-alpha.

METHODS

Chemokine gene expressions were assessed by reverse transcription-polymerase chain reaction, while the releases of chemokines were determined by flow cytometry or enzyme-linked immunosorbent assay (ELISA). To elucidate the intracellular signal transduction regulating the chemokine expression, phosphorylated-extracellular signal-regulated kinase (ERK), phosphorylated-p38 mitogen-activated protein kinase (MAPK) and nuclear translocated nuclear factor (NF)-kappaB-DNA binding were quantitatively assessed by ELISA.

RESULTS

Either SCF or TNF-alpha could induce release from HMC-1 cells of interleukin (IL)-8, monocyte chemoattractant protein (MCP)-1, regulated upon activation normal T-cell expressed and secreted (RANTES), and I-309, while SCF and TNF-alpha induced release of macrophage inflammatory protein (MIP)-1beta and interferon-gamma-inducible protein-10 (IP-10), respectively. Using various selective inhibitors for signaling molecules, we found that the inductions of IL-8, MCP-1, and I-309 were mediated by either SCF-activated ERK or TNF-alpha-activated p38 MAPK, while the induction of IP-10 by TNF-alpha was mediated by both activated p38 MAPK and NF-kappaB. The induction of RANTES by SCF or TNF-alpha was mediated by ERK and NF-kappaB, respectively, and SCF induced MIP-1beta release was mediated by ERK.

CONCLUSION

The above results therefore elucidated the different intracellular signaling pathways regulating the release of different chemokines from SCF and TNF-alpha-activated mast cells, thereby shedding light for the immunopathological mechanisms of mast cell-mediated diseases.

A comprehensive "Healthy Schools Programme" to promote school health: the Hong Kong experience in joining the efforts of health and education sectors

Both health and education are linked to economic performance. The success of education depends on good health, and vice versa. Modern education should help young people to determine values, and accept responsibility for their health and social behaviour. The success of health promotion in schools requires the joint efforts of both the health and education sectors. A comprehensive programme is needed to include teachers' training, curriculum development, community participation, changing policies and practices, and research. All these components are needed to build up a successful model of a health promoting school. The "Healthy Schools Programme" in Hong Kong gives a good example of close partnership between the health and education sectors, and moves towards a multidisciplinary approach and active learning towards health promotion.

Biological activity of immunostimulatory CpG DNA motifs in domestic animals

Bacterial DNA contains a much higher frequency of CpG dinucleotides than are present in mammalian DNA. Furthermore, bacterial CpG dinucleotides are often not methylated. It is thought that these two features in combination with specific flanking bases constitute a CpG motif that is recognized as a "danger" signal by the innate immune system of mammals and therefore an immune response is induced when these motifs are encountered. These immunostimulatory activities of bacterial CpG DNA can also be achieved with synthetic CpG oligodeoxynucleotides (ODN). Recognition of CpG motifs by the innate immune system requires engagement of Toll-like receptor 9 (TLR-9), which induces cell signaling and subsequently triggers a pro-inflammatory cytokine response and a predominantly Th1-type immune response. CpG ODN-induced innate and adaptive immune responses can result in protection in various mouse models of disease. Based on these observations, clinical trials are currently underway in humans to evaluate CpG ODN therapies for cancer, allergy and infectious disease. However, potential applications for immunostimulatory CpG ODN in species of veterinary importance are just being explored. In this review, we will highlight what is presently known about the immunostimulatory effects of CpG ODN in domestic animals.

Prospective randomised trial comparing ayurvedic cutting seton and fistulotomy for low fistula-in-ano

The aim of this study was to evaluate the role of ayurvedic setons in the treatment of low fistula-in-ano. One hundred and eight patients were randomised into either conventional fistulotomy (F) or ayurvedic cutting seton insertion (C). Endpoints investigated included time to wound healing and complications of surgery. Post-operative pain scores were measured daily using a visual analog scale. Anal function was compared using a continence score. Pre- and postoperative manometry and ultrasound were also performed. After exclusions, there were 54 patients in group F and 46 in group C. There were no differences in age, sex or follow-up duration between the two groups. Healing time was similar between the groups. Group C reported more pain following operation and on the first 2-4 postoperative days, but both groups experienced the same amount of pain subsequently. In conclusion, chemical seton was more painful than conventional fistulotomy in the first few days following surgery. However, there was no difference in time to wound healing, complications or functional outcome.

Randomized trial assessing anal sphincter injuries after stapled haemorrhoidectomy

BACKGROUND

Conventional stapled haemorrhoidectomy involves the use of a large circular anal dilator (DL technique), which may cause anal sphincter injuries. This study compared whether the procedure can be effectively performed without this dilator (ND technique), with better sphincter preservation.

METHODS

Fifty-eight patients with symptomatic prolapsed irreducible haemorrhoids were randomized to DL (n = 29) and ND (n = 29) groups. Preoperative continence scoring, anorectal manometry and endoanal ultrasonography were performed. These were repeated at up to 14 weeks after operation, with additional pain scores, analgesic requirements and quality of life assessments.

RESULTS

DL haemorrhoidectomy took significantly longer to perform (P = 0.02). However, there were fewer residual skin tags (P = 0.044) and less perianal pruritus (P = 0.007) at 2 weeks, although such symptoms subsided to an equivalent level in both groups afterwards. Internal anal sphincter fragmentation persisting to at least 14 weeks was found in four patients after DL, but not after ND haemorrhoidectomy (P = 0.038). However, these were asymptomatic and no differences were found in continence scores and anal pressures. The pain scores, satisfaction scores, quality of life assessments and time off work were similar.

CONCLUSION

The large circular anal dilator used for stapled haemorrhoidectomy increased the risk of anal sphincter injuries, which may become problematic with ageing.

Stapled hemorrhoidectomy--cost and effectiveness. Randomized, controlled trial including incontinence scoring, anorectal manometry, and endoanal ultrasound assessments at up to three months

PURPOSE

Stapled hemorrhoidectomy is performed without leaving painful perianal wounds. The aim of this study was to assess any benefits, compared with a conventional open diathermy technique.

METHODS

A total of 119 consecutive patients with prolapsed irreducible hemorrhoids were randomly assigned (conventional open diathermy technique = 62; stapled hemorrhoidectomy = 57). Preoperative fecal incontinence scoring, anorectal manometry, and endoanal ultrasound were performed. Postoperatively, these were repeated at up to three months with pain scores, analgesic requirements, quality of life assessment, and total related medical costs.

RESULTS

Conventional open diathermy technique was quicker to perform (mean, 11.4 (standard error of the mean, 0.9) vs. 17.6 (3.1) minutes). Hospitalization was similar, but conventional open diathermy technique patients felt more pain during defecation (5.1 (0.4) vs. 2.6 (0.4); P < 0.005) at two weeks, and analgesic requirements were more for up to six weeks (P < 0.05). Up to the latter, 85.5 percent conventional open diathermy technique wounds remained unhealed, with more bleeding (33 (53.2 percent) vs. 19 (33.3 percent); P < 0.05) and pruritus (27 (43.5 percent) vs. 9 (15.8 percent); P < 0.05). Total complication rates were similar (conventional open diathermy technique 16 (25.8 percent) vs. stapled hemorrhoidectomy 10 (17.5 percent)), including mild strictures and bleeding in both groups. Minor incontinence occurred postoperatively in two conventional open diathermy technique and two stapled hemorrhoidectomy patients at six weeks. Endoanal ultrasound internal anal sphincter defects were found in the incontinent conventional open diathermy technique patients, but were asymptomatic in another one conventional open diathermy technique and one stapled hemorrhoidectomy. Only one patient (conventional open diathermy technique with internal sphincter defect) remained incontinent at three months. Changes between preoperative and postoperative anorectal manometry were similar in the two groups. Patients' satisfaction scores and quality of life assessments were also similar. Conventional open diathermy technique patients resumed work later (mean 22.9 (1.8) vs. 17.1 (1.9) days; P < 0.05), but the total costs incurred were less ($921.17 (16.85) vs. $1,283.09 (31.59); P < 0.005).

CONCLUSIONS

Stapled hemorrhoidectomy is a safe and effective option in treating irreducible prolapsed piles. It is more expensive but less painful, with less time needed off work. Nonetheless, long-term results are still awaited.

Anal sphincter injuries from stapling instruments introduced transanally: randomized, controlled study with endoanal ultrasound and anorectal manometry

PURPOSE

Injury sustained from the transanally introduced stapling technique was assessed by comparison with biofragmentable anastomotic ring anastomosis, which excluded anal manipulation.

METHODS

A randomized, controlled trial was conducted on consecutive patients undergoing sigmoid colectomy (where pelvic nerve injury was avoided). A bowel function questionnaire was administered six months after surgery. Anorectal manometry and endoanal ultrasonography were performed preoperatively and at six months postoperatively. The observers were blinded to the randomization.

RESULTS

There were 18 patients in the transanally introduced stapling technique group and 17 patients in the biofragmentable anastomotic ring group, with no differences in age, gender, Dukes staging, and follow-up. Three of the transanally introduced stapling technique patients had occasional liquid soiling, which was absent in biofragmentable anastomotic ring patients. Mean change in resting anal pressures was also significantly impaired when compared with patients with biofragmentable anastomotic ring (P = 0.007). Endosonographic internal sphincter fragmentation was found in five transanally introduced stapling technique patients but none after biofragmentable anastomotic ring anastomosis (P = 0.046). Internal sphincter fragmentation was associated with the impaired resting pressures (P = 0.007). External sphincter deficiencies were found after transanally introduced stapling technique in two patients (biofragmentable anastomotic ring = 0), and these were associated with the soiling (P = 0.005).

CONCLUSIONS

The transanally introduced stapling technique may result in anal sphincter defects and impaired anal pressures when assessed at six months of follow-up.

Salivary lysozyme and related parameters of a predominantly Chinese, HIV-infected cohort in Hong Kong

OBJECTIVES

To evaluate the salivary lysozyme concentration, flow rate and pH of a predominantly Chinese, HIV-infected group in Hong Kong, and to compare with an equal number of age and gender-matched HIV-free individuals.

STUDY DESIGN

A prospective longitudinal study over a 12-month period of 32 predominantly Chinese, male, HIV-infected group in a hospital setting in Hong Kong. Whole saliva collection by expectoration, lysozyme evaluation by 'lysoplate method'; pH and flow rate evaluation using standard methods and correlation with other clinical parameters using regression analysis.

RESULTS

The flow rate and the pH of saliva were lower compared with HIV-free, healthy individuals (both P < 0.0001) and salivary lysozyme concentration of the HIV-infected group was 23% higher compared with the HIV-free group (P < 0.001), though there was no significant difference between the lysozyme output (P > 0.05) expressed as microg min-1. On multiple regression analysis, intravenous drug users had a higher salivary lysozyme concentration compared with the homosexual group (P = 0.0015) though other variables investigated were not significantly related to the salivary lysozyme concentrations.

CONCLUSIONS

The significant changes in the flow rate, pH value and lysozyme concentration of whole saliva of the HIV-infected individuals as compared with the HIV-free, healthy individuals, may be due to the disease itself or a combination of factors including the medications used in the disease management.

Skin stapled bowel anastomosis in a canine model

AIM OF STUDY

The aim of this study is to compare the safety and cost effectiveness of the use of staples designed for skin closure in the construction of colonic anastomoses.

METHOD

Twenty healthy dogs were prospectively randomised to either skin stapled or sutured anastomosis. The ascending colon was transected and reanastomosed. This segment was excised and used to test early bursting strength. There was no significant difference between the two groups. The ends of the colon were reanastomosed.

RESULTS

The time taken to perform the anastomosis and the cost of the suture or staples were noted. The time taken for the stapled anastomosis was significantly faster (p < 0.001) with a mean of 7.95 minutes versus a mean of 23.5 minutes for the handsewn anastomosis. The cost was also significantly less (p = 0.18) with a mean of SGD17.85 compared to a mean of SGD21.15 for the handsewn anastomosis. Two weeks later, the dogs were sacrificed and the late bursting pressures were tested and no significant difference was found between the two groups. The anastomotic site was then sent for histological examination. The four animals, one in the handsewn group and 3 in the skin stapled group, dying prior to sacrifice, were subjected to post-mortem.

CONCLUSION

The results show that skin stapled anastomoses are easy to learn and perform and may constitute a viable alternative to hand suture techniques.

Prospective, randomized trial comparing pain and complications between diathermy and scissors for closed hemorrhoidectomy

PURPOSE

The aim of this study was to assess pain and complication rates after closed hemorrhoidectomy with the use of either scissors or diathermy excision.

METHODS

Ninety-one consecutive patients were prospectively randomly assigned by use of sealed envelopes to Group A (diathermy dissection; n = 44) or Group B (scissors dissection; n = 47). The resulting hemorrhoidal pedicle after hemorrhoidal dissection was transfixed and buried under the mucosa, which was closed with 3-0 chromic catgut.

RESULTS

The median time taken for surgery was ten minutes in both groups. The range for Group A was 5 to 25 minutes, and the range for Group B was 5 to 20 minutes. There were no statistically significant differences in the pain scores between the two groups for any of the seven postoperative days studied. The median number of pethidine injections in Group A was 1 and in Group B was 0 (P < 0.009). The number of oral analgesic tablets used was 8 (range, 4-10) and 14 (range, 0-10) for Groups A and B, respectively (P < 0.001). The number of tubes of topical lignocaine jelly used was 14 (range, 0-22) and 14 (range, 7-88) in Groups A and B, respectively. Two patients in each group developed secondary hemorrhage, but no patient had anal stricturing.

CONCLUSION

No excessive complications are seen with closed hemorrhoidectomy, and diathermy seems to require less postoperative analgesic medicine than scissors for closed hemorrhoidectomy except in the first 24 hours.

Reduction of Aqueous Na(2)WO(4) by NaBH(4) at Ambient Temperatures To Obtain Lower Valent Tungsten Oxides

A systematic investigation of the reduction of aqueous Na(2)WO(4) with aqueous NaBH(4) at ambient temperatures reveals the formation of several lower valent tungsten oxides such as the tetragonal (x < 0.38) and cubic (x > 0.43) tungsten bronzes Na(x)()WO(3) and the binary oxides WO(2) and W(24)O(68). The nature of the product formed is influenced both by the (i) reducing power of NaBH(4), which is controlled by the volume and concentration of the borohydride and the reaction pH, and (ii) the degree of condensation of the tungstate ions, which is controlled by the reaction pH. Although the reducing power of NaBH(4) increases with decreasing pH, an increasing degree of condensation of the tungstate tends to lower the degree of reduction in many instances. The as-prepared samples are amorphous as revealed by X-ray diffraction and crystallize around 450 degrees C as revealed by differential scanning calorimerty. The tungsten bronzes undergo interesting crystal-chemical changes with the temperature of heating.

Clinical pathway for pediatric parenteral nutrition

The nutrition support team at Lucile Salter Packard Children's Hospital at Stanford developed a clinical pathway for infants and children receiving parenteral nutrition (PN). Use of clinical pathways for health care delivery is one way in which clinicians and institutions are responding to pressure from managed care organizations to reduce costs and maintain or improve quality. This pathway was developed to standardize the process for ordering, implementing, and monitoring PN. Specific goals for the pathway are as follows: to decrease the number of patients receiving PN inappropriately, to decrease the duration of PN for those patients who require it, to determine complication rates, and to monitor outcomes of therapy. Such comprehensive monitoring will help identify areas for improvement. By developing and implementing action plans to address these issues, we expect to improve continuously the processes and outcomes associated with PN therapy.

Synthesis of Lower Valent Molybdenum Oxides by an Ambient Temperature Reduction of Aqueous K(2)MoO(4) by KBH(4)

Reduction of aqueous K(2)MoO(4) with aqueous KBH(4) at ambient temperatures has been investigated systematically to obtain lower valent molybdenum oxides. Several lower valent oxides such as MoO(2), Mo(4)O(11), K(0.26)MoO(3) (red bronze), K(0.30)MoO(3) (blue bronze), and K(0.85)Mo(6)O(17) are formed during the reduction process; however, only MoO(2) has been obtained as single-phase product. The nature of the product formed is strongly influenced by the reducing power of KBH(4). The reducing power increases with decreasing pH or increasing concentration and volume of KBH(4). The as-prepared samples are amorphous as revealed by X-ray diffraction and transmission electron microscopy. They crystallize sharply at around 350-500 degrees C as revealed by differential scanning calorimetry. Since the products formed are amorphous in nature, they may become particularly attractive for battery electrodes and catalysis.

Selective sedation for colonoscopy

A study of selective sedation for colonoscopy was conducted in two parts. All procedures were performed by one experienced colonoscopist. In the first phase, 41 patients received intravenous sedation before colonoscopy and were then prospectively randomized to either a "not-reversed" group, which did not receive flumazenil before withdrawal of the colonoscope, or to a "reversed" group, which received flumazenil before colonoscope withdrawal. None of the 20 patients reversed and 1 of the 21 patients not reversed experienced pain during the withdrawal phase of colonoscopy. Sixty percent of patients in the reversed group and 10% in the not-reversed group remembered the colonoscopic findings being explained during the procedure. Ninety percent and 81% of patients in the reversed and not-reversed groups, respectively, expressed a preference to be awake to watch the withdrawal of the colonoscope. In the second phase of this study, 40 patients underwent colonoscopy without prior intravenous sedation. Sedation was given only if pain was experienced during the procedure. Thirty percent had no pain at all, 55% minimal pain, 8% moderate pain, and 3% severe pain. Twenty-three percent required intravenous sedation, whereas 78% did not receive any sedation. Ninety-three percent were willing to undergo another colonoscopy without prior sedation. Only 8% preferred prior intravenous sedation before any future colonoscopy.

Selective sedation for colonoscopy

A study of selective sedation for colonoscopy was conducted in two parts. All procedures were performed by one experienced colonoscopist. In the first phase, 41 patients received intravenous sedation before colonoscopy and were then prospectively randomized to either a "not-reversed" group, which did not receive flumazenil before withdrawal of the colonoscope, or to a "reversed" group, which received flumazenil before colonoscope withdrawal. None of the 20 patients reversed and 1 of the 21 patients not reversed experienced pain during the withdrawal phase of colonoscopy. Sixty percent of patients in the reversed group and 10% in the not-reversed group remembered the colonoscopic findings being explained during the procedure. Ninety percent and 81% of patients in the reversed and not-reversed groups, respectively, expressed a preference to be awake to watch the withdrawal of the colonoscope. In the second phase of this study, 40 patients underwent colonoscopy without prior intravenous sedation. Sedation was given only if pain was experienced during the procedure. Thirty percent had no pain at all, 55% minimal pain, 8% moderate pain, and 3% severe pain. Twenty-three percent required intravenous sedation, whereas 78% did not receive any sedation. Ninety-three percent were willing to undergo another colonoscopy without prior sedation. Only 8% preferred prior intravenous sedation before any future colonoscopy.