Cost-effectiveness analysis on screening for colorectal neoplasm and management of colorectal cancer in Asia.

BACKGROUND: Faecal occult blood testing (FOBT), flexible sigmoidoscopy (FS) and colonoscopy are recommended for subjects above 50 years of age for screening for colorectal cancer (CRC). AIM: To evaluate the cost-effectiveness of FOBT, FS and colonoscopy on the basis of disease prevalence, compliance rate and cost of screening procedures in Asian countries. METHODS: A hypothetical population of 100 000 persons aged 50 undergoes either FOBT annually, FS every 5 years or colonoscopy every 10 years until the age of 80 years. Patients with positive FOBT or polyp in FS are offered colonoscopy. Surveillance colonoscopy is repeated every 3 years. The treatment cost of CRC, including surgery and chemotherapy, was evaluated. A Markov model was used to compare the cost-effectiveness of different screening strategies. RESULTS: Assuming a compliance rate of 90%, colonoscopy, FS and FOBT can reduce CRC incidence by 54.1%, 37.1% and 29.3% respectively. The incremental cost-effectiveness ratio (ICER) for FOBT (US$6222 per life-year saved) is lower than FS (US$8044 per life-year saved) and colonoscopy (US$7211 per life-year saved). When the compliance rate drops to 50% and 30%, FOBT still has the lowest ICER. CONCLUSION: FOBT is cost-effective compared to FS or colonoscopy for CRC screening in average-risk individuals aged from 50 to 80 years.

Early and late tuberculosis risks among close contacts in Hong Kong.

SETTING: Tuberculosis (TB) notification is a statutory requirement in Hong Kong, where contact investigations are performed by the Tuberculosis and Chest Service. OBJECTIVES: 1) To evaluate the risk of active TB in close contacts within 5 years, and 2) to identify risk factors associated with early and late development of active TB disease. DESIGN: The characteristics of consecutive TB cases notified from 18 January to 17 April 2000 were collected together with those of their contacts. Contacts were prospectively followed up through the territory-wide TB notification registry for 5 years for the development of disease. RESULTS: A total of 1537 index cases and 4661 close contacts were analysed. Screening found 31 (0.67%) active TB cases within a 3-month period, and another 58 (1.24%) cases presented subsequently. Index cases with cough or pulmonary cavities and diabetic contacts were independent risk factors of early cases (all P<0.05). Adjusted at risk index characteristics for late TB development included positive sputum smear (2.79, 95%CI 1.31-5.95) and family history of TB (4.26, 95%CI 2.01-9.03). Contact risk factors included diabetes mellitus (3.44, 95%CI 1.04-11.33) and institutionalisation (3.61, 95%CI 1.70-7.65). CONCLUSION: Considerable TB risk remains after initial contact screening. A number of possible risk factors were identified.

Effects of electroacupuncture on a degenerated intervertebral disc using an in-vivo rat-tail model.

Electroacupuncture (EA) has long been used as conservative treatment for low back pain (LBP). Its effect on relief of back pain has been demonstrated in many clinical studies. However, whether it has any effect on the biological properties of an intervertebral disc, which is one of the major causes of LBP, is still unclear. The aim of this study was, therefore, to investigate the effects of EA with different simulation frequencies on an intervertebral disc with simulated degeneration using an in-vivo rat-tail model. In this study, 33 rats were used. Disc degeneration was simulated in the rat caudal 8-9 disc via continuous static compressive loading of 11 N for 2 weeks. EA with a frequency of 2 or 100 Hz was then applied to the degenerated disc for 3 weeks with 3 sessions/week and 20 min/session. The intervertebral disc height was measured before and after compression as well as after EA intervention for 3 weeks. The static compression was found to result in a reduction in the disc height of about 22 per cent. There was no evidence that this change could be reversed after resting or the EA intervention. However, EA at 100 Hz was found to induce a further decrease in disc height, which was not shown for the rats after resting or EA at 2 Hz. The results of this study showed that effects of EA on disc degeneration are frequency dependent and adverse effects could result if EA at a certain frequency was used.

Peri-implant inflammation and marginal bone level changes around dental implants in relation to proximity with and bone level of adjacent teeth.

OBJECTIVES: This retrospective study assessed radiographic bone changes and prevalence of inflammation around teeth and neighbouring implants supporting a single-unit fixed dental prosthesis (FDP), in relation to implant- positioning and characteristics. MATERIAL AND METHODS: Patients with an implant-supported FDP in function for at least 1 year were recruited. The radiographic horizontal and vertical position of the implants were identified. Probing depth (PD), bleeding on probing (BOP) and radiographic bone level around implants and adjacent teeth at the time of placement, prosthesis delivery, and the most recent review were assessed. RESULTS: 98 patients with 195 implants were evaluated for a mean of 37.8 months. Survival rate was 99.6% and success ranged from 31.3% to 91.3% when different success criteria were utilized. Significantly greater interproximal bone loss around teeth and higher prevalence of interproximal peri-implant inflammation occurred when the horizontal distance of BL implants was <1 mm, but not with TL implants. There was no significant impact of the corono-apical positioning of the implants on marginal bone loss. CONCLUSION: Proximity of implants to adjacent teeth of <1 mm leads to increased prevalence of inflammation and interproximal bone resorption at the teeth adjacent to bone level implants.

The rising prevalence of self-reported hypertension among Chinese subjects: a population-based study from 121 895 household interviews.

BACKGROUND: Hypertension is one of the most important public health issues worldwide. AIM: We assessed the prevalence rates of self-reported hypertension in Hong Kong between 2001 and 2008 and evaluated factors associated with its prevalence. DESIGN: Serial cross-sectional surveys. METHODS: Territory-wide Household surveys in the Hong Kong population in the years 2001, 2002, 2005 and 2008 were included. Population-adjusted prevalence of self-reported hypertension were compared across calendar years. The independent association of these variables with hypertension was evaluated by multivariate regression analysis with self-reported hypertension as a binary outcome. RESULTS: There were 121 895 subjects interviewed, among which 103 367 were adults aged ≥15 years. The age- and gender-adjusted prevalence of self-reported hypertension in 2001, 2002, 2005 and 2008 among male adults was 4.73, 6.68, 7.96 and 9.82%, respectively, and among female adults, the prevalence was 6.13, 8.28, 10.00 and 11.58%, respectively. Advanced age (adjusted odds ratios [AOR]: 47.1, 95% CI 33.6-66.0 for the age group 40-65 years; AOR 256.2, 95% CI 182.4-360.0 for the age group 66-100 years; referent 0-39 years), female gender (AOR 0.81, 95% CI 0.74-0.88 for male) and a low median household income (AOR 1.56, 95% CI 1.31-1.85 for income ≤ US$1289; referent ≥ US$6444) were significantly associated with hypertension (all P < 0.001). CONCLUSIONS: This is the first study to show differences between socioeconomic groups in this Chinese population with higher rates among women and the less affluent. Similarly, it is the first to show gender differences with higher rates among women.

NADPH-diaphorase neurons in the retina of the hamster.

NADPH-diaphorase-positive neurons have been demonstrated in the inner nuclear layer and ganglion cell layer of the retina of different mammalian species, but so far no experiments have been conducted to identify whether these cells are amacrine cells and/or retinal ganglion cells. We attempted to solve this problem by studying the NADPH-diaphorase-positive neurons in the hamster retina. From the NADPH-diaphorase histochemical reaction, two distinct types of neurons in the hamster retina were identified. They were named ND(g) and ND(i) cells. The ND(g) cells were cells with larger somata, ranging from 10 to 21 microns in diameter with a mean of 15.58 microns (S.D. = 2.59). They were found in the ganglion cell layer only. The ND(i) cells were smaller, with the somata ranging from 7 to 11 microns and having the mean diameter of 8.77 microns (S.D. = 1.24). Most of the ND(i) cells were found in the inner nuclear layer, and only very few could be observed in the inner plexiform layer. On average, there were 8,033 ND(g) and 5,051 ND(i) cells in the ganglion cell layer and inner nuclear layer, respectively. Two experiments were performed to clarify whether any of the NADPH-diaphorase neurons were retinal ganglion cells. Following unilateral optic nerve section, which leads to the retrograde degeneration of retinal ganglion cells, the numbers of both ND(g) and ND(i) cells did not change significantly for up to 4 months. In addition, when retinal ganglion cells were prelabeled retrogradely (horseradish peroxidase or fluorescent microspheres) and retinas were then stained for NADPH diaphorase, no double-labeled neurons were detected. These results indicated that the NADPH-diaphorase neurons in the hamster retina were the amacrine cells in the inner nuclear layer and displaced amacrine cells in the ganglion cell layer. Dendrites of the ND(g) and ND(i) cells were found to stratify in sublaminae 1, 3, and 5 of the inner plexiform layer, with a prominent staining in the sublamina 5. The possible importance of this arrangement in the rod pathway is also discussed.

Partial patellectomy induces a decrease in the proteoglycan content in the remaining patellar articular cartilage. An experimental study in rabbits.

We studied the alterations and distribution of the proteoglycan (PG) content of the remaining patellar articular cartilage after unilateral partial patellectomy in 13 rabbits. Sagittal sections of the patella were prepared and stained with Safranin O for quantification of changes in the PG content of the patellar articular cartilage using a commercially available imaging analysis system. Our findings suggest that partial patellectomy results in a decreased PG content in the remaining patellar articular cartilage. In addition, the postoperative development of metaplasia in the scar tissue next to the healing interface may represent a compensatory response, which could prevent a further reduction in the PG content and hence the development of osteoarthritis in the remaining patellar articular cartilage.

A brief method for assessing social development: structure, reliability, stability, and developmental validity of the Interpersonal Competence Scale.

The Interpersonal Competence Scale (ICS-T) is a set of brief rating scales for teachers and parents. It consists of 18 items that assess social and behavioural characteristics of children and youths. The ICS-T yields three primary factors: AGG (argues, trouble at school, fights), POP (popular with boys, popular with girls, lots of friends), and ACA (spelling, math). Subsidiary factors include AFF (smile, friendly), OLY (appearance, sports, wins), and INT (shyness, sad, worry). The psychometric properties of the scale (internal structure, reliability, long-term stability) are presented and evaluated over successive ages. The scale factors have been linked to contemporaneous observations of behavior and social network membership. Developmental validity of the ICS-T includes the significant prediction of later school dropout and teenage parenthood. The ICS-T scale is described, along with instructions for use and scoring.

Paths across generations: academic competence and aggressive behaviors in young mothers and their children.

This research compared the social and cognitive development of young mothers when they were children with the social and cognitive development of their offspring. Intergenerational development was investigated over a 17-year period for 57 women who had been studied longitudinally from childhood to adulthood and who became young mothers (R. B. Cairns & B. D. Cairns, 1994). The children of these women, in turn, were followed prospectively from 1 to 2 years old through the early school years. The academic competence of mothers when they were children was significantly linked to the academic competence of their children at school age. In contrast, the across-generation correlations between measures of aggressive behavior of the mothers when they were children and measures of aggressive behavior of their children in early school grades were modest and unreliable. Certain within-generation continuities were observed in both cognitive and aggressive development.

Characteristics of workers attending the pneumoconiosis clinic for silicosis assessment in Hong Kong: retrospective study.

OBJECTIVE: To describe and analyse the baseline characteristics of workers attending the pneumoconiosis clinic for assessment of silicosis. DESIGN: Retrospective cross-sectional study. SETTING: Outpatient clinic. PATIENTS: One thousand and fifty-six patients with silica dust exposure attending the pneumoconiosis clinic for compensation assessment. MAIN OUTCOME MEASURES: Baseline demographic characteristics, lung function parameters, and radiographic findings. RESULTS: Six hundred and forty-eight patients were diagnosed with silicosis, of which 10 were female. Excluding the data on female patients, the mean duration of dust exposure was 24.2 years. The majority of patients were involved in caisson work and stone splitting. Most newly diagnosed patients had simple silicosis. Less than a quarter (24.8%) had progressive massive fibrosis. Lung function parameters at diagnosis were within the normal range. Pulmonary tuberculosis remained an important co-existing disease. CONCLUSION: The major cause of silicosis in Hong Kong is chronic silica dust exposure in the construction industry. Simple silicosis predominated at diagnosis, with normal lung function parameters seen in the majority of patients.

The effect of low-energy laser irradiation on apoptotic factors following experimentally induced transient cerebral ischemia.

Apoptosis, or programmed cell death, resulting from cerebral ischemia may be related to decreased levels of anti-apoptotic factors, such as serine/threonine kinase (Akt), phosphorylated Akt (pAkt), pBAD, and Bcl-2, and increased levels of pro-apoptotic factors, such as BAD, caspase 9, and caspase 3 activities. In this study, we investigated the effects of low-energy laser (660 nm) irradiation (LLI) on the levels and activity of various anti- and pro-apoptotic factors following ischemia. Transient cerebral ischemia was induced in Sprague-Dawley rats by unilateral occlusion of the middle cerebral artery for 1 h, followed by reperfusion. LLI was then directed on the cerebrum for varying lengths of duration (1, 5, or 10 min at an energy density of 2.64 J/cm², 13.2 J/cm², and 24.6 J/cm², respectively). The expression levels of Akt, pAkt, BAD, pBAD, Bcl-2, caspase 9, and caspase 3 activities were measured 4 days after injury. The levels of Akt, pAkt, Bcl-2, and pBAD were significantly increased following laser irradiation. In addition, LLI significantly decreased caspase 9 and caspase 3 activities caused by ischemia-reperfusion. LLI may protect the brain by upregulating Akt, pAkt, pBAD, and Bcl-2 expression and downregulating caspase 9 and caspase 3 expression following transient cerebral ischemia. This modality is a promising protective therapeutic intervention after strokes or other ischemic events.

Combined treatment of therapeutic laser and herbal application improves the strength of repairing ligament.

The present study investigated the effects of combined therapeutic laser and herbal medication protocols on injured medial collateral ligaments (MCLs) of rat knees. Fully 36 rats were evenly divided into 9 groups. Right MCLs of groups 1 to 6 and 8 were transected, while that of groups 7 and 9 remained intact. After surgery, group 1 was treated with 1 session of high-dosed laser; group 2 with 9 sessions of low-dosed laser; group 3 with an herbal plaster; groups 4 and 5 received combined treatments of groups 1 and ss and 2, and 3 respectively; groups 6 and 7 received only bandaging; groups 8 and 9 received placebo laser and no treatment, respectively. All MCLs were subjected to biomechanical testing at 3 weeks postsurgery. Results revealed significant differences among groups in ultimate tensile strength (UTS) and stiffness (p < 0.01). Combination of multiple low-dosed laser treatment with herbal treatment (group 5) resulted in higher UTS than either no treatment (groups 6 and 8), single high-dosed laser treatment (group 1), multiple low-dosed laser treatment (group 2), or herbal treatment (group 2) alone. We concluded that combined applications of laser and herb can enhance further biomechanical properties of repairing rat MCLs than separate applications at 3 weeks postinjury.

Friendships and social networks in childhood and adolescence: fluidity, reliability, and interrelations.

Social networks and friendships were tracked over a 3-week period for 132 students enrolled in fourth- and seventh-grade classrooms. Individual interviews were employed to collect data on friendships. Social group membership was determined by the composite social-cognitive map (SCM) procedure and by self-reports. Considerable overlap was found among the methods for establishing relational patterns (i.e., friendships, self-reported groups, composite social-cognitive maps). When loose criteria for stability were employed, high stability was found in friendships (p = .56-.75) and social group membership (p = .90) over a 3-week period. But when stringent criteria were employed, only modest social relationship stability was observed in both methods, suggesting that there is much greater fluidity in peer bonds than has been generally recognized. The relationship between friendship and social network measures, the distinctive information yielded by social networks, and gender and age differences in group structure, fluidity, and friendships are discussed.

Investigation of the collagen fibril distribution in the medial collateral ligament in a rat knee model.

This study compared the collagen fibril diameter distribution among six anatomical sites of the rat medial collateral ligament (MCL). Ultrathin MCL sections from 4 male Sprague-Dawley rats were examined electron microscopically. With an automated quantitation method, 41,638 fibrils were measured and compared among the periphery and core regions of the femoral, middle, and tibial portions of the MCL. Results demonstrated significant difference (p < .0033) in mean fibril diameter distribution among the six sites. The mass-averaged diameters of the core and peripheral fibrils were between 175.53 to 190.82 nm and 88.47 to 109.18 nm, respectively, with the peripheral fibrils more homogeneous in size. The fibrils occupied 36.7% to 57.1% of the cross-sectional area of the ligament. About 50% of the fibrils had an oblique factor of 0.8-1.0, implying that most fibrils were aligned longitudinally. This study has provided a detailed profile of the collagen fibril distributions in rat MCL.

Secretin controls anion secretion in the rat epididymis in an autocrine/paracrine fashion.

There is growing evidence that secretin, the first hormone discovered in our history, has functions in the brain other than in the gastrointestinal tract. This article reports for the first time that secretin and its receptor mRNAs are produced in distinct cell types within the epididymis. To test if secretin affects electrolyte transport in the epididymis, we measured short-circuit current (Isc) in cultured epididymal epithelia and found secretin dose-dependently stimulated Isc. Ion substitution experiments and use of pharmacological agents inferred that the stimulated Isc is a result of concurrent electrogenic chloride and bicarbonate secretion. It is further shown that secretin and pituitary adenylate cyclase-activating polypeptide (PACAP) function via totally different mechanisms: 1) PACAP works only from the apical side of the epithelium to stimulate chloride and not bicarbonate secretion, while secretin acts on the apical and basolateral sides to stimulate chloride and bicarbonate secretion. 2) the stimulation by PACAP but not secretin requires local prostaglandin synthesis. By immunocytochemical staining, secretin is localized in the principal cells of the initial segment and caput epididymidis, whereas secretin receptor is present in the principal cells of the proximal as well as the distal part of the epididymis. This pattern of distribution appears to be consistent with the idea that secretin is secreted by the proximal epididymis and acts on the proximal and distal epididymis in an autocrine and paracrine fashion. Its function is to control secretion of electrolytes and water.