Shigella flexneri serotype 1 infections in men who have sex with men in Vancouver, Canada.

OBJECTIVES: Outbreaks of shigellosis have been documented in men who have sex with men (MSM), associated with interpersonal transmission and underlying HIV infection. We observed a rise in Shigella flexneri isolates identified in a downtown tertiary-care hospital laboratory located within the city centre community health area (CHA-1) of Vancouver, Canada. The objectives of this study were to evaluate clinical outcomes of shigellosis cases among MSM admitted to hospital and to evaluate trends in Shigella cases within Vancouver, Canada. METHODS: Adult rates of shigellosis were analysed by gender and health region, from 2005 to 2011, followed by retrospective chart review of all hospital laboratory-identified S. flexneri cases from 2008 to 2012. Serotyping and pulsed-field gel electrophoresis (PFGE) were performed on these isolates. RESULTS: Although shigellosis rates in men within CHA-1 did not change from 2005 to 2011 (range 33.4-68.5 per 100 000; P = 0.74), they were significantly higher than in other regions within the city of Vancouver (P ≤ 0.001) and the province of British Columbia (P ≤ 0.001). Shigella flexneri rates in men within CHA-1 increased significantly (range 2.3-51.4 per 100 000; P < 0.001), starting in 2008, and were higher than in other regions within Vancouver (P ≤ 0.01). Seventy-nine isolates of S. flexneri from 72 patients were identified by a single hospital laboratory. All patients were male and predominantly MSM (91.7%) and HIV-infected (86.1%), with most (92.6%) demonstrating CD4 counts ≥ 200 cells/µL. In total, 38.0% required hospitalization. Most (87.3%) had S. flexneri serotype 1 infection, with 72.9% of these representing a single PFGE pattern. CONCLUSIONS: We identified high levels of transmission of a primarily clonal strain of S. flexneri serotype 1 in our local MSM population, resulting in a substantial burden of illness and health care resource use secondary to hospital admissions.

Cost-effectiveness analysis of human papillomavirus DNA testing and Pap smear for cervical cancer screening in a publicly financed health-care system.

OBJECTIVE: to evaluate the long-term cost-effectiveness of different strategies for human papillomavirus (HPV) DNA testing combined with Pap smear for cervical cancer screening in Taiwan. METHODS: this study adopts a perspective of Department of Health in cost-effectiveness analysis to compare a no-screening strategy with nine different screening strategies. These strategies comprise three screening tools (Pap smear alone, HPV DNA testing followed by Pap smear triage, and HPV DNA testing combined with Pap smear), and three screening intervals (annually, every 3 years, and every 5 years). Outcomes are life expectancy, quality-adjusted life years (QALYs), lifetime costs, and incremental cost-effectiveness ratios (ICERs). Probabilistic sensitivity analyses (PSAs) were conducted to assess parameter uncertainty. RESULTS: when three times gross domestic product per capita is used as the decision threshold, all nine screening strategies were cost-effective compared with the no-screening strategy. Compared with the current screening strategy (an annual Pap smear), HPV DNA testing followed by Pap smear triage every 5 years and every 3 years were cost-effective. Results of PSA also indicated that a HPV DNA testing followed by Pap smear triage every 5 or every 3 years achieved the highest expected net benefits. CONCLUSIONS: possible economic advantages are associated with extending the cervical cancer screening interval from one Pap smear annually to HPV DNA testing followed by Pap smear triage every 5 years with an ICER $1 247 000 per QALY gained, especially in a country with a publicly financed health-care system.

Socioeconomic inequalities in cancer survival in England after the NHS cancer plan.

BACKGROUND: Socioeconomic inequalities in survival were observed for many cancers in England during 1981-1999. The NHS Cancer Plan (2000) aimed to improve survival and reduce these inequalities. This study examines trends in the deprivation gap in cancer survival after implementation of the Plan. MATERIALS AND METHOD: We examined relative survival among adults diagnosed with 1 of 21 common cancers in England during 1996-2006, followed up to 31 December 2007. Three periods were defined: 1996-2000 (before the Cancer Plan), 2001-2003 (initialisation) and 2004-2006 (implementation). We estimated the difference in survival between the most deprived and most affluent groups (deprivation gap) at 1 and 3 years after diagnosis, and the change in the deprivation gap both within and between these periods. RESULTS: Survival improved for most cancers, but inequalities in survival were still wide for many cancers in 2006. Only the deprivation gap in 1-year survival narrowed slightly over time. A majority of the socioeconomic disparities in survival occurred soon after a cancer diagnosis, regardless of the cancer prognosis. CONCLUSION: The recently observed reduction in the deprivation gap was minor and limited to 1-year survival, suggesting that, so far, the Cancer Plan has little effect on those inequalities. Our findings highlight that earlier diagnosis and rapid access to optimal treatment should be ensured for all socioeconomic groups.

Declines in tobacco brand recognition and ever-smoking rates among young children following restrictions on tobacco advertisements in Hong Kong.

BACKGROUND: We compared the recognition of tobacco brands and ever-smoking rates in young children before (1991) and after (2001) the implementation of cigarette advertising restrictions in Hong Kong and identified continuing sources of tobacco promotion exposure. METHODS: A cross-sectional survey of 824 primary school children aged from 8 to 11 (Primary classes 3-4) living in two Hong Kong districts was carried out using self-completed questionnaires examining smoking behaviour and recognition of names and logos from 18 tobacco, food, drink and other brands common in Hong Kong. RESULTS: Ever-smoking prevalence in 2001 was 3.8 per cent (1991, 7.8 per cent). Tobacco brand recognition rates ranged from 5.3 per cent (Viceroy name) to 72.8 per cent (Viceroy logo). Compared with 1991, in 2001 never-smoker children recognized fewer tobacco brand names and logos: Marlboro logo recognition rate fell by 55.3 per cent. Similar declines were also seen in ever-smoker children, with recognition of the Marlboro logo decreasing 48 per cent. Recognition rates declined amongst both boys and girls. Children from non-smoking families constituted 51 per cent (426) of the sample, whereas 34.5 per cent (284), 8.5 per cent (70), 1.7 per cent (14) and 4.4 per cent (36) of the children had one, two, three or more than three smoking family members at home, respectively. Tobacco brand recognition rates and ever-smoking prevalence were significantly higher among children with smoking family members compared with those without. Among 12 possible sources of exposure to cigarette brand names and logos, retail stalls (75.5 per cent; 622), indirect advertisements (71.5 per cent; 589) and magazines (65.3 per cent; 538) were ranked the most common. CONCLUSION: Advertising restrictions in Hong Kong have effectively decreased primary-age children's recognition of tobacco branding. However, these children remain vulnerable to branding, mostly through exposure from family smokers, point-of-sale tobacco advertisement and occasional promotions. Action to curb these is now required.

The use of genotyping to predict the phenotypes of human platelet antigens 1 through 5 and of neutrophil antigens in Taiwan.

BACKGROUND: The human platelet antigen (HPA) 1 through 5 and the human neutrophil antigen (HNA-1) systems are relevant to immune-related thrombocytopenia and neutropenia. The alloantigen distribution profiles in the population will aid in estimating the risk of alloimmunization. STUDY DESIGN AND METHODS: Genotyping of the genes that control the expression of the HPA-1 through -5 and HNA-1 systems in Taiwanese (n = 326) and Taiwan's indigenous peoples (n = 608) was performed by PCR with the sequence-specific primer (PCR-SSP) method. RESULTS: In the HPA system, HPA-1b and HPA-4b were absent among Taiwan's indigenous tribes and detected among other Taiwanese only with frequencies of <0.2 percent and <0.5 percent, respectively. The GP1BA*2 (HPA-2b) and GP1A*2 (HPA-5b) allele frequencies range from 1 percent to 7 percent and 0.4 percent to 3.5 percent among the two ethnic groups, respectively. GP2B*1 (HPA-3a) and GP2B*2 (HPA-3b) showed similar allele frequencies. In the HNA-1 system, the FCGR3B*1 (HNA-1a) allele frequency was about twice that of FCGR3B*2 (HNA-1b) in Taiwanese and also in most of the indigenous tribes. Three FCGR3B (HNA-1) null persons were found in one indigenous tribe (Ami tribe), for an FCGR3B null frequency of 19.8 percent. However, no FCGR3B*3 (HNA-1c) allele was detected in Taiwan. CONCLUSION: The frequencies of HPA-1b, -2b, and -5b in the Taiwanese population were much lower than those among whites. In Taiwan, all of the HNA-1 null found was due to the deletion of the FCGR3B gene, and this deletion may be widely distributed in the Ami tribe.

Monte Carlo simulation of a clinical linear accelerator.

The effects of the physical parameters of an electron beam from a Siemens PRIMUS clinical linear accelerator (linac) on the dose distribution in water were investigated by Monte Carlo simulation. The EGS4 user code, OMEGA/BEAM, was used in this study. Various incident electron beams, for example, with different energies, spot sizes and distances from the point source, were simulated using the detailed linac head structure in the 6 MV photon mode. Approximately 10 million particles were collected in the scored plane, which was set under the reticle to form the so-called phase space file. The phase space file served as a source for simulating the dose distribution in water using DOSXYZ. Dose profiles at Dmax (1.5 cm) and PDD curves were calculated following simulating about 1 billion histories for dose profiles and 500 million histories for percent depth dose (PDD) curves in a 30 x 30 x 30 cm3 water phantom. The simulation results were compared with the data measured by a CEA film and an ion chamber. The results show that the dose profiles are influenced by the energy and the spot size, while PDD curves are primarily influenced by the energy of the incident beam. The effect of the distance from the point source on the dose profile is not significant and is recommended to be set at infinity. We also recommend adjusting the beam energy by using PDD curves and, then, adjusting the spot size by using the dose profile to maintain the consistency of the Monte Carlo results and measured data.

Thermodontic stimulator--a new technology for assessment of thermal dentinal hypersensitivity.

A clinical investigation of the reproducibility of threshold and pain temperature scores obtained from use of the Thermodontic Stimulator (TDS) is reported. The TDS is designed for accurate clinical testing of thermal dentinal hypersensitivity. This instrument employs a variable stimulus/fixed response approach to clinical testing of thermal dentinal hypersensitivity. The TDS consists of a probe in a handpiece, a patient signaling device (joystick), a computer, and interface electronics. The TDS provides a precise means of assessing and recording the temperature which elicits a response to thermal stimulation from the subject being evaluated. Two temperatures are recorded. The threshold temperature is recorded when the patient is first able to sense that a cold stimulus has been applied to the tooth. The second score, pain temperature, is recorded when the subject first notices discomfort. Twenty-two subjects participated in this study. Results obtained from the 21 subjects who completed this study (one subject dropped out for non-compliance) demonstrated a reproducibility standard deviation of 1.1 degrees C for the threshold temperature, and 2.8 degrees C for the pain temperature for the duration of the study. There was a good degree of correlation between the measurements of any two test days (Pearson's correlation coefficient). There was no significant difference between the mean pain temperature scores of any two testing days.

Prostate-specific antigen in screening of prostate cancer.

Prostate-specific antigen (PSA) is a well-characterized human prostate-specific glycoprotein. PSA has been shown to be the most effective immunohistologic marker for prostate cancer, as well as the most useful serologic test in staging and monitoring prostate cancer and in early detection of recurrent disease. The greatest clinical value of PSA is an aid for early detection of prostate cancer. Recent studies have indicated that PSA-based screening of the older population for organ-confined early-stage prostate cancer is an acceptable, practical, and reliable modality. The accuracy of PSA screening is within the same range as the mammogram. The cost-effectiveness of PSA is comparable to other cancer screening tests. Although the increase in the patient's survival due to PSA-based detection of early prostate cancer remains to be documented, it is generally agreed that the PSA test along with digital rectal examination (DRE) should be included in the annual physical examination for men 50 years of age or older. High-risk men are urged to commence at age 40. Asymptomatic men who have both a negative DRE and normal PSA blood test need only to continue an annual DRE and PSA check-up. Men who have a negative DRE and elevated PSA, and all those who have a suspicious DRE regardless of PSA results, should undergo further diagnostic workup, such as transrectal ultrasonography with biopsy of visible lesions. The cure rate is high with timely treatment, when prostate cancer is detected while still confined to the prostate.

An assessment of bone scans for monitoring osseous metastases in patients being treated for prostate carcinoma.

The National Prostatic Cancer Project held a workshop in March 1980 to examine procedures used to evaluate bone metastases. Variations in techniques used by each of 9 treatment centers, as well as the National Cancer Institute, were compared. One center in particular had developed procedures for quantitating bone scans in addition to the customary qualitative evaluation. Changes in bone scan assessments were also related to changing levels of isoenzymes of acid and alkaline phosphatase. Most consistently correlated with disease changes were prostatic acid phosphatase, as determined by counter-immunoelectrophoresis, and the isoenzyme of bone alkaline phosphatase. Gamma cameras were recommended over rectilnear scanners as were multiple spot films to concentrate on problem areas. Bone scans must be performed prior to therapy and for best assessment no sooner than 3 months to avoid the flair phenomenon. Consistency of both machine settings and patient position are paramount, as are quality of equipment and review of past scans and X-ray films where appropriate to obtain the best assessment of disease status.

Human chorionic gonadotrophins (hCG) in non-trophoblastic neoplasms. Assessment of abnormalities of hCG and CEA in bronchogenic and digestive neoplasms.

Evaluation of plasma hCG measurement in the diagnosis of nontrophoblastic neoplasms and assessment of the value of concomitant measurement of plasma hCG and CEA in patients with bronchogenic carcinoma and neoplasms of the digestive tract were undertaken. Only one of 70 normal control subjects had positive plasma hCG (3.5 ng/ml), whereas 54 of 320 patients with nontrophoblastic neoplasms had measurable plasma hCG (1.9 to 160 ng/ml). Forty of these patients had less than 5.1 ng/ml. Elevated plasma CEA levels of 3.6 to 140 ng/ml were found in 38 of the 70 patients with bronchogenic carcinoma and 30 of the 72 patients with neoplasms of the digestive tract in this series. Concomitant positive hCG was found in only six of the 68 patients who had elevated CEA levels, and positive hCG was found in eight of 74 patients who had normal plasma CEA. The low frequency and the modest elevation of plasma hCG, despite frequent advanced disease, indicate plasma hCG has limited value as a biologic marker for diagnosis and assessment of non-trophoblastic neoplasms.