Phosphorus retention in a mesotrophic lake under transient loading conditions: insights from a sediment phosphorus binding form study

Phosphorus retention in sediments has been estimated for three basins in Lake Simcoe, a mesotrophic lake in Ontario, Canada. Total phosphorous (TP) fractionation was used to examine the concentration of phosphorus (P) binding forms in the sediments of Cook's Bay, Kempenfelt Bay, and the Main Basin. The extended sequential extractions allowed us to differentiate between organic-, inorganic-, carbonate-bounded and redox-sensitive phosphorus. Our results showed different mechanisms of P release in each of the three investigated basins, which may be linked to their distinct loading histories, present land-uses and morphology of the sampling sites. In the deep Main Basin, where moderate changes in P loading have been induced by deforestation, sediments are not an important long-term source of diagenetically mobile P, as almost 75% of P is released within a short time scale. P release is predominantly generated by a continuous epilimnetic P flux, rather than a large inventory of temporary P stored in the sediments. Diagenesis in the upper sediment layers is fast enough to prevent a large accumulation of temporary P. In the much deeper glacially formed Kempenfelt Bay with a highly urbanized catchment, P release from the sediments is dominated by the redox-sensitive P fraction, representing up to 40% and 57% of long- and short-term sediment P release, respectively. In the shallow and agriculturally-impacted Cook's Bay, the main P binding form that can be mobilized through diagenesis is carbonate-bound P. This fraction contributes 40.1% and 37.6% to the long- and short-term P sediment release, respectively. Although different mechanisms of P release have been revealed for the three basins in Lake Simcoe, the vertical profiles indicate that the sediments throughout the system are still able to bind deposited P.

Effects of fish oil supplementation on inflammatory acne

Background

Given that acne is a rare condition in societies with higher consumption of omega-3 (n-3) relative to omega-6 (n-6) fatty acids, supplementation with n-3 may suppress inflammatory cytokine production and thereby reduce acne severity.

Methods

13 individuals with inflammatory acne were given three grams of fish oil containing 930 mg of EPA to their unchanged diet and existing acne remedies for 12 weeks. Acne was assessed using an overall severity grading scale, total inflammatory lesion counts, and colorimetry.

Findings

There was no significant change in acne grading and inflammatory counts at week 12 compared to baseline. However, there was a broad range of response to the intervention on an individual basis. The results showed that acne severity improved in 8 individuals, worsened in 4, and remained unchanged in 1. Interestingly, among the individuals who showed improvement, 7 were classified as having moderate to severe acne at baseline, while 3 of the 4 whose acne deteriorated were classified as having mild acne.

Conclusion

There is some evidence that fish oil supplementation is associated with an improvement in overall acne severity, especially for individuals with moderate to severe acne. Divergent responses to fish oil in our pilot study indicates that dietary and supplemental lipids are worthy of further investigation in acne.

Online memory screening--are older adults interested and can it work?

Subjective memory concerns are common in older adults and may prompt the use of web-based cognitive screening. Websites which purport to provide memory screening are numerous and can influence health behaviours; however there is currently limited evidence regarding their validity. The current research aims to assess potential user's attitudes and motivations regarding online cognitive screening and to evaluate the preliminary evidence for the feasibility and validity of two subjective online cognitive measures. The sample consisted of community-based older adults, 30 with, and 30 without, memory concerns. Participants rated their likelihood of their accessing online cognitive screening and gave rationales. Participants' performance on objective pen and paper measures of cognition was compared to performance on subjective online screening measures. The majority of participants indicated they would access online cognitive screening. A total of 100% of participants were able to use the online tools without assistance. None of the online measures was positively associated with the pen and paper screening measures. Anxiety and depression were significantly associated with subjective memory concerns. This study provided no supporting evidence for the validity of either subjective online screening measure assessed. Anxiety and depression were significantly associated with subjective cognition, indicating that, although they may not predict objective cognition, complaints about memory in older adults should be taken seriously by health professionals.

Control of type 1 diabetes mellitus and shift work

BACKGROUND

People with type 1 diabetes may find diabetic control more difficult when working shifts.

AIMS

To investigate the proportion of people with type 1 diabetes in employment undertaking shift work and diabetic control as assessed by glycosylated haemoglobin (HbA1c) among individuals undertaking shift work compared to those not doing so.

METHODS

A postal questionnaire sent to all those aged 16-65 attending two city hospitals for type 1 diabetes care. HbA1c results were used to assess diabetic control.

RESULTS

Twenty-two per cent (296 of 1370 eligible patients) responded. Sixty-seven (23%) respondents were involved in shift work. Shift workers had higher mean HbA1c values than non-shift workers (9.02 versus 8.35; P < 0.01).

CONCLUSIONS

Poorer control of diabetes was associated with working shifts in this study. Occupational health practitioners should be aware of this association and be able to advise on management strategies to improve diabetic control while working shifts.

Incidence and outcomes of pregnancy-associated cancer in Australia, 1994-2008: a population-based linkage study

Objective

To determine trends in pregnancy-associated cancer and associations between maternal cancer and pregnancy outcomes.

Design

Population-based cohort study.

Setting

New South Wales, Australia, 1994–2008.

Population

A total of 781 907 women and their 1 309 501 maternities.

Methods

Cancer and maternal information were obtained from linked cancer registry, birth and hospital records for the entire population. Generalised estimating equations with a logit link were used to examine associations between cancer risk factors and pregnancy outcomes.

Main outcome measures

Incidence of pregnancy-associated cancer (diagnosis during pregnancy or within 12 months of delivery), maternal morbidities, preterm birth, and small- and large-for-gestational-age (LGA).

Results

A total of 1798 new cancer diagnoses were identified, including 499 during pregnancy and 1299 postpartum. From 1994 to 2007, the crude incidence rate of pregnancy-associated cancer increased from 112.3 to 191.5 per 100 000 maternities (P < 0.001), and only 14% of the increase was explained by increasing maternal age. Cancer diagnosis was more common than expected in women aged 15–44 years (observed-to-expected ratio 1.49; 95% CI 1.42–1.56). Cancers were predominantly melanoma (33.3%) and breast cancer (21.0%). Women with cancer diagnosed during pregnancy had high rates of labour induction (28.5%), caesarean section (40.0%) and planned preterm birth (19.7%). Novel findings included a cancer association with multiple pregnancies (adjusted odds ratio 1.52, 95% CI 1.13–2.05) and LGA (aOR 1.47, 95% CI 1.14–1.89).

Conclusions

Pregnancy-associated cancers have increased, and this increase is only partially explained by increasing maternal age. Pregnancy increases women’s interaction with health services and the possibility for diagnosis, but may also influence tumour growth.

Transmission rate and reproductive number of the H5N1 highly pathogenic avian influenza virus during the December 2005-July 2008 epidemic in Nigeria

We quantified the between-village transmission rate, β (the rate of transmission of H5N1 HPAI virus per effective contact), and the reproductive number, Re (the average number of outbreaks caused by one infectious village during its entire infectious period), of H5N1 highly pathogenic avian influenza (HPAI) virus in Nigeria using outbreak data collected between December 2005 and July 2008. We classified the outbreaks into two phases to assess the effectiveness of the control measures implemented. Phase 1 (December 2005-October 2006) represents the period when the Federal Government of Nigeria managed the HPAI surveillance and response measures, while Phase 2 (November 2006-July 2008) represents the time during which the Nigeria Avian Influenza Control and Human Pandemic Preparedness project (NAICP), funded by a World Bank credit of US$ 50 million, had taken over the management of most of the interventions. We used a total of 204 outbreaks from 176 villages that occurred in 78 local government areas of 25 states. The compartmental susceptible-infectious model was used as the analytical tool. Means and 95% percentile confidence intervals were obtained using bootstrapping techniques. The overall mean β (assuming a duration of infectiousness, T, of 12 days) was 0.07/day (95% percentile confidence interval: 0.06-0.09). The first and second phases of the epidemic had comparable β estimates of 0.06/day (0.04-0.09) and 0.08/day (0.06-0.10), respectively. The Re of the virus associated with these β and T estimates was 0.9 (0.7-1.1); the first and second phases of the epidemic had Re of 0.84 (0.5-1.2) and 0.9 (0.6-1.2), respectively. We conclude that the intervention measures implemented in the second phase of the epidemic had comparable effects to those implemented during the first phase and that the Re of the epidemic was low, indicating that the Nigeria H5N1 HPAI epidemic was unstable.

Recurrent and founder mutations in the PMS2 gene

Germline mutations in PMS2 are associated with Lynch syndrome (LS), the most common known cause of hereditary colorectal cancer. Mutation detection in PMS2 has been difficult due to the presence of several pseudogenes, but a custom-designed long-range PCR strategy now allows adequate mutation detection. Many mutations are unique. However, some mutations are observed repeatedly across individuals not known to be related due to the mutation being either recurrent, arising multiple times de novo at hot spots for mutations, or of founder origin, having occurred once in an ancestor. Previously, we observed 36 distinct mutations in a sample of 61 independently ascertained Caucasian probands of mixed European background with PMS2 mutations. Eleven of these mutations were detected in more than one individual not known to be related and of these, six were detected more than twice. These six mutations accounted for 31 (51%) ostensibly unrelated probands. Here, we performed genotyping and haplotype analysis in four mutations observed in multiple probands and found two (c.137G>T and exon 10 deletion) to be founder mutations and one (c.903G>T) a probable founder. One (c.1A>G) could not be evaluated for founder mutation status. We discuss possible explanations for the frequent occurrence of founder mutations in PMS2.

SU-E-T-577: Dosimetric Comparison of Volumetric Modulated Arc Therapy (VMAT), Step and Shoot and Sliding Window IMRT for Prostate Cancer

PURPOSE

This study aims to evaluate treatment plans generated by Step- and-Shoot (SS), Sliding Window (SW) and Volumetric Modulated Arc Therapy (VMAT) in order to assess the differences in dose volume histograms of planning target volume (PTV) and organs at risk (OAR), conformity indices, radiobiological evaluations, and plan quality for prostate cancer cases.

METHODS

Six prostate cancer patients treated in our center were selected for this retrospective study. Treatment plans were generated with Eclipse version 8.9 using 10 MV photon beams. For VMAT, Varian Rapid Arc with 1 or 2 arcs, and for SS and SW IMRT, 7-9 fields were used. Each plan had three PTVs with prescription doses of 81, 59.4, and 45 Gy to prostate, to prostate and lymph nodes, and to pelvis, respectively. Doses to PTV and OAR and the conformal indices (COIN) were compared among three techniques. The equivalent uniform dose (EUD), tumor control probability (TCP) and normal tissue complication probability (NTCP) was also calculated and compared.

RESULTS

The mean doses to the PTV prostate on average were 83 Gy and the percent differences of mean dose among all techniques were below 0.28. For bladder and rectum, the percent differences of mean dose among all techniques were below 2.2. The COIN did not favour any particular delivery method over the other. The TCP was higher with SS and SW for four patients and higher with VMAT for two patients. The NTCP for the rectum was the lowest with VMAT in all patients except one.

CONCLUSIONS

Preliminary data shows similar target coverage in general. We will extend our study to include 15 patients to compare different approaches with statistics. We will attempt to define characteristics predictive of the superior delivery technique.

Epidemiology of Burkitt's lymphoma in Northwest Province, Cameroon, 2003-2010

BACKGROUND

Burkitt's lymphoma (BL) is an aggressive non-Hodgkin's lymphoma endemic to regions of Africa. Cases are thought to be typically found in low-lying, humid regions where malaria is rife.

AIMS AND OBJECTIVES

To investigate the clinical characteristics of BL, its incidence and relationship with malarial incidence in Northwest (NW) Province, Cameroon.

METHODS

Data on BL were collected from the three tertiary referral centres for BL treatment in NW Province, Cameroon. Data on malaria were collected from the Delegation of Public Health in Bamenda, NW Province. Data were collected between March and May 2010.

RESULTS

471 cases of BL were identified. The St Jude's stage of patients at presentation was as follows: stage I, 14.4% (43/299); stage II, 8.4% (25/299); stage III, 69.9% (209/299); stage IV, 7.4% (22/299). The incidences of BL per 100,000 children <15 years of age from 2005 to 2009 were as follows: 2005, 3.01 (29); 2006, 2.02 (20); 2007, 2.45 (25); 2008, 2.38 (25); 2009, 3.06 (33). The average incidence in NW Province was 2.58. In the Ndop plain, Ngo-Ketunjia, the incidences of BL were as follows: 2005, 10.3 (10); 2006, 3.00 (3); 2007, 1.95 (2); 2008, 2.84 (3); 2009, 4.60 (5). The average incidence was 4.54/100,000 children <15 years of age. Statistical analysis demonstrated a sinusoidal distribution of malaria cases throughout the year (P<0.00), with a peak incidence on 10 April. Conversely, no sinusoidal distribution of BL cases was demonstrated throughout the year (P = 0.09).

CONCLUSION

No relationship was demonstrated between an acute malarial infection and BL. Significant clustering was found, with the low-lying Ndop plain of Ngo-Ketunjia having an incidence of BL nearly twice that elsewhere in the region. The study demonstrates that the incidence of BL in NW Province, Cameroon remains one of the highest documented in the world.

Adrenal involvement in MEN1. Analysis of 715 cases from the Groupe d'etude des Tumeurs Endocrines database

OBJECTIVE

Limited data regarding adrenal involvement in multiple endocrine neoplasia type 1 (MEN1) is available. We describe the characteristics of MEN1-associated adrenal lesions in a large cohort to provide a rationale for their management.

METHODS

Analysis of records from 715 MEN1 patients from a multicentre database between 1956 and 2008. Adrenal lesions were compared with those from a multicentre cohort of 144 patients with adrenal sporadic incidentalomas.

RESULTS

Adrenal enlargement was reported in 20.4% (146/715) of patients. Adrenal tumours (>10 mm in size) accounted for 58.1% of these cases (10.1% of the whole patient cohort). Tumours were bilateral and >40 mm in size in 12.5 and 19.4% of cases respectively. Hormonal hypersecretion was restricted to patients with tumours and occurred in 15.3% of them. Compared with incidentalomas, MEN1-related tumours exhibited more cases of primary hyperaldosteronism, fewer pheochromocytomas and more adrenocortical carcinomas (ACCs; 13.8 vs 1.3%). Ten ACCs occurred in eight patients. Interestingly, ACCs occurred after several years of follow-up of small adrenal tumours in two of the eight affected patients. Nine of the ten ACCs were classified as stage I or II according to the European Network for the Study of Adrenal Tumors. No evident genotype/phenotype correlation was found for the occurrence of adrenal lesions, endocrine hypersecretion or ACC.

CONCLUSIONS

Adrenal pathology in MEN1 differs from that observed in sporadic incidentalomas. In the absence of relevant symptoms, endocrine biology can be restricted to patients with adrenal tumours and should focus on steroid secretion including the aldosterone-renin system. MEN1 is a high-risk condition for the occurrence of ACCs. It should be considered regardless of the size of the tumour.

Patient perceptions of an art-making experience in an outpatient blood and marrow transplant clinic

This study explored blood and marrow transplantation (BMT) patients' perceptions of an art-making experience during BMT treatment. Participants including patients receiving BMT for a variety of cancers (10 men/10 women, aged 20-68) were offered a 1 hour tile-painting activity during treatment. Participants with cognitive impairment and respiratory precautions were excluded from the study. Researchers followed immune precaution protocols for the safety of participants. Data were collected through semi-structured, in-depth interviews with 20 participants to gather information about their perceptions of the art-making experience in a BMT clinic setting. Interview recordings were transcribed verbatim and analysed. Researchers coded transcripts independently and discussed outcomes together to achieve agreement on themes. Twelve themes emerged from the data, with the three most prevalent themes being Occupying Time (20.5%), Creative Expression (13.5%), and Reactions to Tile Painting (13.5%). Other themes included Support (12.2%), Side Effects (7.3%), Other Activities Suggested by Patients (7%), BMT Treatment Process (6.2%), Shared Painting Experience (5.9%), Life Outlook (5.2%), BMT Life Changes (3.8%), Spirituality (3%) and Barriers (1.9%). Through analysis of these themes, researchers have identified this art-making experience as a diversional or meaningful way to spend time during treatment, a medium for creative expression, and a distraction from negative side effects of the BMT process.

Stenting large bowel obstruction avoids a stoma: consecutive series of 100 patients

AIM

Large bowel obstruction (LBO) is a surgical emergency that requires urgent operative intervention and often a stoma. The introduction of a self-expanding metallic stent provides an alternative for this group of patients. The aim of this study was to assess prospectively the results in the first 100 consecutive patients with LBO undergoing attempted self-expanding metallic stent insertion at the Royal Prince Alfred Hospital, Sydney, Australia.

METHOD

A prospective consecutive uncontrolled trial of 100 patients having an attempted self-expanding metallic stent insertion for LBO was performed after institutional ethical approval.

RESULTS

The mean age was 63.9 years (range 16-95). Primary colorectal cancer was the most common cause of LBO (61%). A self-expanding metallic stent was inserted with a palliative intent in 89% of patients. An initial technical success rate of 87% was achieved. Overall 30-day mortality was 7% (95% CI, 3.4-13.7%), with only one stent-related death within 30 days of stent insertion. Morbidity occurred in 20% of patients. Surgery was avoided in 69 patients and permanent stoma was avoided in 72 patients. The median follow up was 34.5 months (range 1-64 months).

CONCLUSION

In this uncontrolled study, self-expanding metallic stents had a low morbidity and a low procedure-related mortality. A randomized controlled trial has commenced in our institution, in which length of stay, quality of life, morbidity and mortality of patients with stents are compared with those of patients having open procedures during palliative care for LBO.

Array comparative genomic hybridization analysis of small supernumerary marker chromosomes in human infertility

Small supernumerary marker chromosomes (sSMC) are structurally abnormal chromosomes that cannot be unambiguously identified by conventional banding cytogenetics. This study describes four patients with sSMC in relation with infertility. Patient 1 had primary infertility. His brother, fertile, carried the same sSMC (patient 2). Patient 3 presented polycystic ovary syndrome and patient 4 primary ovarian insufficiency. Cytogenetic studies, array comparative genomic hybridization (CGH) and sperm analyses were compared with cases previously reported. sSMC corresponded to the 15q11.2 region (patients 1 and 2), the centromeric chromosome 15 region (patient 3) and the 21p11.2 region (patient 4). Array CGH showed 3.6-Mb gain for patients 1 and 2 and 0.266-Mb gain for patient 4. Sperm fluorescent in-situ hybridization analyses found ratios of 0.37 and 0.30 of sperm nuclei with sSMC(15) for patients 1 and 2, respectively (P < 0.001). An increase of sperm nuclei with disomy X, Y and 18 was noted for patient 1 compared with control and patient 2 (P < 0.001). Among the genes mapped in the unbalanced chromosomal regions, POTE B and BAGE are related to the testis and ovary, respectively. The implication of sSMC in infertility could be due to duplication, but also to mechanical effects perturbing meiosis.