High HIV-1 prevalence,risk behaviours,and willingness to participate in HIV vaccine trials in fishing communities on Lake Victoria,Uganda

Introduction

HIV epidemics in sub-Saharan Africa are generalized, but high-risk subgroups exist within these epidemics. A recent study among fisher-folk communities (FFC) in Uganda showed high HIV prevalence (28.8%) and incidence (4.9/100 person-years). However, those findings may not reflect population-wide HIV rates in FFC since the study population was selected for high-risk behaviour.

Methods

Between September 2011 and March 2013, we conducted a community-based cohort study to determine the population representative HIV rates and willingness to participate (WTP) in hypothetical vaccine trials among FFC, Uganda. At baseline (September 2011–January 2012), a household enumeration census was done in eight fishing communities (one lakeshore and seven islands), after which a random sample of 2200 participants aged 18–49 years was selected from 5360 individuals. Interviewer-administered questionnaire data were collected on HIV risk behaviours and WTP, and venous blood was collected for HIV testing using rapid HIV tests with enzyme-linked immunosorbent assay (EIA) confirmation. Adjusted prevalence proportion ratios (adj.PPRs) of HIV prevalence were determined using log-binomial regression models.

Results

Overall baseline HIV prevalence was 26.7% and was higher in women than men (32.6% vs. 20.8%, p<0.0001). Prevalence was lower among fishermen (22.4%) than housewives (32.1%), farmers (33.1%) and bar/lodge/restaurant workers (37%). The adj.PPR of HIV was higher among women than men (adj.PPR =1.50, 95%; 1.20, 1.87) and participants aged 30–39 years (adj.PPR=1.40, 95%; 1.10, 1.79) and 40–49 years (adj.PPR=1.41, 95%; 1.04, 1.92) compared to those aged 18–24 years. Other factors associated with HIV prevalence included low education, previous marriage, polygamous marriage, alcohol and marijuana use before sex. WTP in hypothetical vaccine trials was 89.3% and was higher in men than women (91.2% vs. 87.3%, p=0.004) and among island communities compared to lakeshore ones (90.4% vs. 85.8%, p=0.004).

Conclusions

The HIV prevalence in the general fisher-folk population in Uganda is similar to that observed in the “high-risk” fisher folk. FFC have very high levels of willingness to participate in future HIV vaccine trials.     

Attachment and psychological well-being among adolescents with and without disabilities in Kenya: The mediating role of identity formation

The current study is aimed at evaluating the relationship between attachment and identity development, and their influence on psychological well-being in adolescents with and without disabilities in Kenya. The sample was composed of 296 adolescents (151 with disabilities and 145 without any disability). The mean age in our sample was 16.84 years (SD = 1.75). Adolescents with disabilities had significantly lower scores in identity formation, paternal attachment, and life satisfaction. A path model indicated that identity formation partially mediated the relationship between secure attachment and psychological well-being. Our findings indicate that both parent and peer attachment play an important role in the identity formation and psychological well-being of adolescents in Kenya, irrespective of a disabling condition. A multigroup analysis indicated that while the structure of the relationship between variables held for groups, the pattern and strength of the relationships differed. Implications for practice, especially the guidance and counseling services in schools, are discussed.     

Learning face–name associations in early-stage dementia: Comparing the effects of errorless learning and effortful processing

Some recent studies suggest that errorless learning principles may be beneficial in memory rehabilitation for people with dementia, while others indicate that effortful processing may be more important. The present study compared the effects of four different learning techniques, varying in level of effort required and number of errors elicited, on free recall, cued recall and recognition of novel and previously known associations among people with early-stage dementia. Ten participants with a diagnosis of early-stage Alzheimer's, vascular or mixed dementia learned novel and previously familiar face–name associations with each of four techniques – vanishing cues, forward cues, target selection, and paired associate learning – in a within-subjects design. All conditions produced significant learning for both novel and familiar associations. There were no significant differences between conditions, although mean scores were slightly higher for errorful conditions. Reducing errors did not produce any benefits. Enhancing level of effort had no significant effects for familiar associations, but high-effort conditions were significantly more effective than low-effort conditions in facilitating cued recall of novel associations. The results confirm that memory rehabilitation techniques can produce significant benefits, but do not support the view that error reduction during learning facilitates greater improvement in early-stage dementia. Effort enhancement may be more important, especially when learning novel associations.     

Rekonstruktion von Segmentdefekten der langen Röhrenknochen

Surgery of malignant tumors and the subsequent outcome after treatment of complicated fracture situations of long bones often result in major bone defects. In addition to bridging of defects and stabilization with allogenic implants, defect reconstruction by callus distraction with segment transport and vascularized free fibula transfer are the procedures of choice for defect reconstruction in long bones. The heterogeneity of the causes of large bone defects and specific comorbidities of the patients require a differentiated approach. The indications and characteristics of the various surgical approaches and current developments in procedures for reconstruction of large defects in long bones are presented.     

Perception and Awareness of Bariatric Surgery in Canada: a National Survey of General Surgeons

Background

The objective of this study was to assess Canadian general surgeons’ knowledge of bariatric surgery and perceived availability of resources to manage bariatric surgery patients.

Methods

A self-administered questionnaire was developed using a focus group of general surgeons. The questionnaire was distributed at two large general surgery conferences in September and November 2012. The survey was also disseminated via membership association electronic newsletters in November and December 2012.

Results

One hundred sixty-seven questionnaires were completed (104 practicing surgeons, 63 general surgery trainees). Twenty respondents were bariatric surgeons. Among 84 non-bariatric surgeons, 68.3 % referred a patient in the last year for bariatric surgery, 79 % agreed that bariatric surgery resulted in sustained weight loss, and 81.7 % would consider referring a family member. Knowledge gaps were identified in estimates of mortality and morbidity associated with bariatric procedures. The majority of surgeons surveyed have encountered patients with complications from bariatric surgery in the last year. Over 50 % of surgeons who do not perform bariatric procedures reported not feeling confident to manage complications, 35.4 % reported having adequate resources and equipment to manage morbidly obese patients, and few are able to transfer patients to a bariatric center. Of the respondents, 73.3 % reported residency training provided inadequate exposure to bariatric surgery, and 85.3 % felt that additional continuing medical education resources would be useful.

Conclusions

There appears to be support for bariatric surgery among Canadian general surgeons participating in this survey. Knowledge gaps identified indicate the need for more education and resources to support general surgeons managing bariatric surgical patients.

     

Atrophy rates of the cingulate gyrus and hippocampus in AD and FTLD

This study explores the diagnostic utility of atrophy rates of the cingulate gyrus, its subdivisions and the hippocampus in Alzheimer's disease (AD) and frontotemporal lobar degeneration (FTLD). Regions were manually outlined on MR images of a group of pathologically or genetically confirmed patients with AD (n=19), FTLD (n=8) and age-matched controls (n=11). Mean (S.D.) atrophy rates (%year(-1)) in the cingulate in controls, AD and FTLD were -0.3 (1.2), 5.9 (3.5), and 8.6 (4.1), respectively. Hippocampal atrophy rates in controls, AD and FTLD were -0.1 (0.8), 3.4 (2.2), and 5.2 (5.4), respectively. Atrophy rates were significantly higher in the cingulate and hippocampi in AD and FTLD compared with controls (p<0.01). There was evidence of a difference in trends of atrophy in the cingulate (more anterior in FTLD and more posterior in AD) between the disease groups (p=0.03). Cingulate atrophy rates discriminated perfectly between FTLD and controls. Significantly better discrimination between AD and controls was obtained by hippocampal rather than cingulate rates. In conclusion, cingulate atrophy is as significant a feature of AD and FTLD as hippocampal atrophy.     

Phantom experiments to improve parathyroid lesion detection

This investigation tested the hypothesis that visual analysis of iteratively reconstructed tomograms by ordered subset expectation maximization (OSEM) provides the highest accuracy for localizing parathyroid lesions using 99mTc-sestamibi SPECT data. From an Institutional Review Board approved retrospective review of 531 patients evaluated for parathyroid localization, image characteristics were determined for 85 99mTc-sestamibi SPECT studies originally read as equivocal (EQ). Seventy-two plexiglas phantoms using cylindrical simulated lesions were acquired for a clinically realistic range of counts (mean simulated lesion counts of 75 +/- 50 counts/pixel) and target-to-background (T:B) ratios (range = 2.0 to 8.0) to determine an optimal filter for OSEM. Two experienced nuclear physicians graded simulated lesions, blinded to whether chambers contained radioactivity or plain water, and two observers used the same scale to read all phantom and clinical SPECT studies, blinded to pathology findings and clinical information. For phantom data and all clinical data, T : B analyses were not statistically different for OSEM versus FB, but visual readings were significantly more accurate than T : B (88 +/- 6% versus 68 +/- 6%, p = 0.001) for OSEM processing, and OSEM was significantly more accurate than FB for visual readings (88 +/- 6% versus 58 +/- 6%, p < 0.0001). These data suggest that visual analysis of iteratively reconstructed MIBI tomograms should be incorporated into imaging protocols performed to localize parathyroid lesions.     

Patient dose considerations for routine megavoltage cone-beam CT imaging

Megavoltage cone-beam CT (MVCBCT), the recent addition to the family of in-room CT imaging systems for image-guided radiation therapy (IGRT), uses a conventional treatment unit equipped with a flat panel detector to obtain a three-dimensional representation of the patient in treatment position. MVCBCT has been used for more than two years in our clinic for anatomy verification and to improve patient alignment prior to dose delivery. The objective of this research is to evaluate the image acquisition dose delivered to patients for MVCBCT and to develop a simple method to reduce the additional dose resulting from routine MVCBCT imaging. Conventional CT scans of phantoms and patients were imported into a commercial treatment planning system (TPS: Phillips, Pinnacle) and an arc treatment mimicking the MVCBCT acquisition process was generated to compute the delivered acquisition dose. To validate the dose obtained from the TPS, a simple water-equivalent cylindrical phantom with spaces for MOSFETs and an ion chamber was used to measure the MVCBCT image acquisition dose. Absolute dose distributions were obtained by simulating MVCBCTs of 9 and 5 monitor units (MU) on pelvis and head and neck patients, respectively. A compensation factor was introduced to generate composite plans of treatment and MVCBCT imaging dose. The article provides a simple equation to compute the compensation factor. The developed imaging compensation method was tested on routinely used clinical plans for prostate and head and neck patients. The quantitative comparison between the calculated dose by the TPS and measurement points on the cylindrical phantom were all within 3%. The dose percentage difference for the ion chamber placed in the center of the phantom was only 0.2%. For a typical MVCBCT, the dose delivered to patients forms a small anterior-posterior gradient ranging from 0.6 to 1.2 cGy per MVCBCT MU. MVCBCT acquisitions in the pelvis and head and neck areas deliver slightly more dose than current portal imaging but render soft tissue information for positioning. Overall, the additional dose from daily 9 MU MVCBCTs of prostate patients is small compared to the treatment dose (<4%). Dose-volume histograms of compensated plans for pelvis and head and neck patients imaged daily with MVCBCT showed no additional dose to the target and small increases at low doses. The results indicate that the dose delivered for MVCBCT imaging can be precisely calculated in the TPS and therefore included in the treatment plan. This allows simple plan compensations, such as slightly reducing the treatment dose, to minimize the total dose received by critical structures from daily positioning with MVCBCT. The proposed compensation factor reduces the number of MU per treatment beam per fraction. Both the number of fractions and the beam arrangement are kept unchanged. Reducing the imaging volume in the cranio-caudal direction can further reduce the dose delivered for MVCBCT. This is a useful feature to eliminate the imaging dose to the eyes or to focus on a specific region of interest for alignment.