Haemophilia utilization group study - Part Va (HUGS Va): design, methods and baseline data

To describe the study design, procedures and baseline characteristics of the Haemophilia Utilization Group Study - Part Va (HUGS Va), a US multi-center observational study evaluating the cost of care and burden of illness in persons with factor VIII deficiency. Patients with factor VIII level ≤ 30%, age 2-64 years, receiving treatment at one of six federally supported haemophilia treatment centres (HTCs) were enrolled in the study. Participants completed an initial interview including questions on socio-demographical characteristics, health insurance status, co-morbidities, access to care, haemophilia treatment regimen, factor utilization, self-reported joint pain and motion limitation and health-related quality of life. A periodic follow-up survey collected data regarding time lost from usual activities, disability days, health care utilization and outcomes of care. HTC clinicians documented participants' baseline clinical characteristics and pharmacy dispensing records for 2 years. Between July 2005 and July 2007, 329 participants were enrolled. Average age was 9.7 years for children and 33.5 years for adults; two-thirds had severe haemophilia. The distributions of age, marital status, education level and barriers to haemophilia care were relatively consistent across haemophilic severity categories. Differences were found in participants' employment status, insurance status and income. Overall, children with haemophilia had quality of life scores comparable to healthy counterparts. Adults had significantly lower physical functioning than the general US population. As one of the largest economic studies of haemophilia care, HUGS Va will provide detailed information regarding the burden of illness and health care utilization in the US haemophilia A population.

Exemestane for primary prevention of breast cancer in postmenopausal women: NCIC CTG MAP.3—A randomized, placebo-controlled clinical trial

LBA504

Background: Limited efficacy and serious toxicities have limited uptake of tamoxifen or raloxifene as preventatives of breast cancer. Aromatase inhibitors (AIs) prevent contralateral breast cancers more than tamoxifen in adjuvant trials and have fewer serious side effects. This is the first report of an AI used in primary prevention. Methods: NCIC CTG MAP.3 is a randomized trial designed to detect a 65% reduction in annual incidence of invasive breast cancer (IBC) on exemestane (E) versus placebo (P). Eligible postmenopausal women had ≥ one of the following risk factors: Gail score >1.66%, prior ADH, ALH, LCIS or DCIS with mastectomy, age over 60. Health-related and menopause-specific quality of life (QOL) were assessed by SF-36 and MENQOL questionnaires. Results: From 2004-2010, 4,560 women were randomized: age 62.5 yrs (37-90); Gail Score 2.3 % (0.6-21); BMI 28.0 kg/m2 (15.9-65.4). Risk factors included: age >60 yrs (49%); Gail score >1.66 (40%); and prior ADH, ALH, LCIS or DCIS with mastectomy (11%). At median follow-up of 35 months there were 11 IBCs on E and 32 on P (annual incidence 0.19% vs 0.55%; HR= 0.35, 95% CI 0.18-0.70, p = 0.002); ductal (10E/27P), lobular (1E/5P). Most tumors were ER positive (7E/27P); Her2/neu negative (10E/26P); TNM stage T1 (8E/28P), N0 (7E/22P), M0 (11E/30P). E was superior in all subgroups: by Gail score, age, BMI, prior LCIS and DCIS. The annual incidence rate of IBC or DCIS was 0.35% E and 0.77% P (HR=0.47;95% CI 0.27-0.79; p = 0.004) based on 64 IBCs or DCISs (20E/44P). Clinical bone fractures, osteoporosis, hypercholesterolemia or cardiovascular events were equal in both arms. No clinically meaningful differences in QOL were detected. Conclusions: Exemestane significantly reduced invasive and pre-invasive breast cancers in postmenopausal women at increased risk for breast cancer with no serious toxicities. Exemestane should be considered a new option for primary prevention of breast cancer. Supported by the Canadian Cancer Society; Pfizer Inc. PEG supported in part by Avon Foundation.

The effect of spatial resolution on wall shear stress measurements acquired using radial phase contrast magnetic resonance angiography in the middle cerebral arteries of healthy volunteers. Preliminary results

We have recently implemented radial phase-contrast techniques that allow high resolution angiograms with velocity information to be acquired within clinically-useful imaging times. 10 healthy volunteers were scanned using PC-VIPR and PC-SOS, two high resolution phase-contrast techniques at spatial resolutions of 0.67×0.67×0.67 mm(3) and 0.4×0.4×1 mm(3) respectively. The velocity measurements from the two acquisitions were imported into a custom Matlab runtime environment that automatically calculated WSS values using Green's Theorem and B-spline interpolation. Time average axial WSS was 1.069 N/m(2) (95% confidence interval: 0.8628< x < 1.276) in the left and right middle cerebral arteries of the 10 healthy volunteers (n=20) when scanned by PC-VIPR, and 1.670 N/m(2) when scanned by PC-SOS (95% confidence interval: 1.395 < x < 1.946). This difference in means was statistically significant (p < 0.002). Previous investigators have found that higher spatial resolution results in higher WSS measurements because smaller voxel size results in fewer partial volume effects. This was true in our study as well. In this study, we found that PC-SOS has significantly higher spatial resolution than PC-VIPR and this followed in the WSS measurements. Higher in-plane spatial resolution allows WSS calculations to be performed more accurately because of increased precision near the vessel boundary.

Rates and risk factors for contagious disease and mortality in young dairy heifers

Abstract

Dairy heifers, particularly when <3 months, are at high risk for mortality and morbidity. Accurate data are lacking because of poor recording on farm, difficulties over disease diagnosis and potential bias of farm selection. Mortality during rearing varied from 6 to 14% between studies. The range from 0 to 30% on individual farms suggested that deaths are preventable with good husbandry. Contagious disease was the major cause of mortality at <6 months, with trauma, accidents and infertility more important in older animals. Bovine respiratory disease (BRD) and diarrhoea were the most common diseases. Both are endemic, low-mortality and high-morbidity conditions. The prevalence of diarrhoea was 19-35%, with higher incidences during disease outbreaks. Cryptosporidium parvum and rotavirus were the dominant pathogens. The causative pathogens for BRD were harder to identify, with large differences between levels of farmer- and veterinarian-diagnosed disease and higher incidences in North America (around 16%) than Europe (around 3%). Analysis of the risk factors for disease and mortality highlighted that closed herds, good hygiene and availability of roughage were consistently associated with improved outcomes. Some common practices were challenged by the results of large, prospective studies. Calf diarrhoea was only weakly associated with good passive transfer of immunity via colostrum, suggesting other control strategies are required. Morbidity with small group housing demonstrated no disadvantages compared with contiguous single pens, so this system should be encouraged to improve welfare. Routine use of antibiotics in calf diarrhoea was associated with negative outcomes, so is actively discouraged.

Abstract P1-08-04: Doses of Selective Estrogen Receptor Modulations (SERMS) Required for Prevention and Therapy of Chemically-Induced Mammary Cancers

Selective Estrogen Receptor Modulators (SERMs) interfere with the activation of the estrogen receptor. SERMs have been shown to be effective for both treatment and prevention of breast cancer. Here we examine the ability of tamoxifen and arzoxifene, a more easily absorbed form of raloxifene, to prevent mammary tumors at a significantly lower dosage than those used for treatment. For prevention studies, female Sprague-Dawley rats (50 days of age) were injected with a single i.v. dose of MNU resulting in the development of multiple ER-positive mammary tumors beginning 7 weeks after carcinogen treatment. Rats were administered the preventive agent beginning five days after carcinogen administration. When the agents were tested at does varying between 0.15-3.3 ppm in the diet, both agents caused a dose dependent increase in preventive activity. The highest doses of tamoxifen (3.3 ppm) and arzoxifene (3.0 ppm) both decreased tumor multiplicity greater than 90%. Both of these doses are less than one-fifth the human equivalent dose (HED) based on standard FDA scaling factors. Both doses also resulted in substantial decreases in mammary gland development. These dosages were then used in a therapy setting to compare the efficacy. For these studies, MNU treated rats were allowed to develop their first palpable mammary tumor (70-150 mm2) before initiating treatment. Tumor growth or regression was followed by caliper measurements. Neither of the preventive doses of these SERMs exhibited therapeutic activity although substantially higher doses of tamoxifen (33 or 100 ppm) were relatively effective. These results are in contrast to our prior findings with other classes of agents (RXR agonists, EGFR inhibitors, and aromatase inhibitors) in which highly effective preventive doses were as effective as therapeutic doses in this model. These results demonstrate the unique dose differential regarding prevention and therapy with SERMs. Microarray analysis of tumors treated for 5 days with tamoxifen at doses of 3.3ppm or 100ppm reveals overlapping significant gene changes of similar magnitude in comparison to control treated tumors although there were significant gene changes seen at the therapeutic dose which were not observed at the lower dose. These studies raise two questions: 1) whether this class of agents might be used at significantly lower doses in a pure prevention setting as contrasted with a therapeutic setting where they were initially defined; 2) are there gene expression changes which might be used to help identify this differential dosing for prevention vs. therapy.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-08-04.

Hernia recurrence through a composite mesh secondary to transfascial suture holes

Laparoscopic ventral hernia repair is an accepted method for incisional hernia repair. Although techniques vary, transfascial suturing of the mesh to the abdominal wall has been proposed as a viable way to fixate the mesh and reduce recurrence rates. We report a 54-year-old woman who had previously undergone a laparoscopic ventral hernia repair following a laparoscopic tubal ligation using a Composix mesh. The patient presented with a symptomatic hernia recurrence. The computed tomography scan showed a periumbilical hernia containing fat. The patient underwent diagnostic laparoscopy and lysis of adhesions. During the lysis of adhesions, a recurrence through the previously placed composite mesh was encountered where holes had been made by the previously placed transfascial sutures. The hernia was reduced, mesh was removed, and an ePTFE mesh was used to repair the hernia. The mechanism of recurrence appeared to be improperly placed transfascial sutures; overly large bites of mesh caused excessive tension and ultimately a hole in the mesh. Hernia recurrence due to mesh or transfascial suture failure is rarely reported and most often caused by inadequate fixation. Our case highlights the need for meticulous placement of transfascial sutures and demonstrates a mechanism of recurrence due to inadequate placement.

Continuous long-term immunomodulatory therapy in relapsing multiple sclerosis: results from the 15-year analysis of the US prospective open-label study of glatiramer acetate

The ongoing US Glatiramer Acetate (GA) Trial is the longest evaluation of continuous immunomodulatory therapy in relapsing-remitting multiple sclerosis (RRMS). The objective of this study was to evaluate up to 15 years of GA as a sole disease-modifying therapy. Two hundred and thirty-two patients received at least one GA dose since study initiation in 1991 (mITT cohort), and 100 (43%, Ongoing cohort) continued as of February 2008. Patients were evaluated every 6 months using the Expanded Disability Status Scale (EDSS). Mean GA exposures were 8.6 +/- 5.2, 4.81 +/- 3.69, and 13.6 +/- 1.3 years and mean disease durations were 17, 13, and 22 years for mITT, Withdrawn and Ongoing cohorts, respectively. For Ongoing patients, annual relapse rates (ARRs) maintained a decline from 1.12 +/- 0.82 at baseline to 0.25 +/- 0.34 per year; 57% had stable/improved EDSS scores (change < or = 0.5 points); 65% had not transitioned to secondary progressive multiple sclerosis (SPMS); 38%, 18%, and 3% reached EDSS 4, 6, and 8. For all patients on GA therapy (the mITT cohort), ARRs declined from 1.18 +/- 0.82 to 0.43 +/- 0.58 per year; 54% had stable/improved EDSS scores; 75% had not transitioned to SPMS; 39%, 23%, and 5% reached EDSS 4, 6, and 8. In conclusion, multiple sclerosis patients with mean disease duration of 22 years administering GA for up to 15 years had reduced relapse rates, and decreased disability progression and transition to SPMS. There were no long-term safety issues.

Meeting Healthy People 2010 objective 1.7 in ASAHP programs

A key objective of Healthy People 2010, a program of the U.S. Public Health Service, falls within the responsibility of member programs of the Association of Schools of Allied Health Professions (ASAHP). Objective 1.7 reads, "Increase the proportion of schools of medicine, schools of nursing and health professional training schools whose basic curriculum for health care providers includes the core competencies in health promotion and disease prevention." In light of the upcoming development of Healthy People 2020, this paper explores four specific topics related to Objective 1.7 outlined in the Clinical Prevention and Population Health Curriculum Framework, recommended by experts from a number of health disciplines, and whether or not ASAHP programs include these topics in their curricula. Survey data would indicate that many of the elements of the four topics are covered. A few key subjects, however, are not covered by all programs. For example, both immunization and preventive medicine are not included in required courses of a majority of the respondents. The development of health policy and understanding global health issues appear also to be lacking. Health professions educators are advised to consider the health promotion and disease prevention aspects of their curricula.

Retrospective review of the use of daptomycin for diabetic foot infections

The increase in antibiotic resistance has led to a search for alternative treatments for diabetic foot infections. This retrospective review outlines the clinical outcomes reported for a lipopetide for these infections.

Electronic prescribing via the internet for a coronary artery disease and hypertension megatrial

A unique feature of the International Verapamil SR/Trandolapril Study (INVEST) is the Internet-based, electronic data capture system developed at the University of Florida for this trial. This system allows for direct collection of patient enrollment data, randomization, study drug prescribing, and real-time monitoring of patient data online. In this trial, immediate transmission of patient-specific data occurs using online data collection forms. Investigators only need a personal computer with access to the Internet: no complicated hardware, software systems, or paper storage files are necessary. INVEST is the first large randomized clinical trial to use electronic prescribing systems in the research setting. Electronic prescribing eliminates errors associated with illegible handwriting, inappropriate dosing, and inappropriate medication choice. Because the INVEST protocol allows flexibility of medication choice and dosage range within randomly assigned treatment strategies based on patient tolerance and blood pressure response, physician investigators may use individual practice patterns and preferences. The electronic system provides guidance to physicians relative to the addition of medication or dosage adjustments within the protocol. Electronic tracking and reporting mechanisms have enabled investigators in this complex megatrial to enroll, randomize, and manage patients in real time with great accuracy.

Voluntary patient assistance programs: additional federal oversight unwarranted

The Partnership for Prescription Assistance, which links struggling patients to more than 475 patient assistance programs, provides a vital safety net for millions of uninsured Americans. Proposing unwarranted government regulation during these uncertain economic times could cast a chill nationwide on other philanthropic efforts.

Gene set enrichment analysis to evaluate expression of autoantigens in lung cancer

e22048

Background: There is a well-established association between certain autoimmune diseases and the development of specific malignancies. It has been demonstrated that myositis-specific autoantigens are expressed at higher levels in tumors associated with myositis compared to normal tissue, suggesting that immune responses to antigens expressed in nascent tumors may contribute to the autoimmune process. Whether this observation is a general feature of autoantigen expression in tumor tissue, and whether the relative expression of these antigens is enriched in relation to the rest of the tumor transcriptome is currently unknown. Methods: Tumor tissue from ten lung cancer biopsies (adenocarcinoma (4), carcinoid (4), and squamous cell carcinoma (2)) and normal lung from the same patients were obtained. Total RNA was extracted and hybridized to Illumina Sentrix BeadChips. Hiearchical clustering was used to visualize the expression levels of 146 known autoantigens. Gene Set Enrichment Analysis was performed using 20 disease-specific autoantigen gene sets and 1892 gene sets from the Molecular Signatures Database. Protein levels of selected autoantigens were assessed by immunoblotting detergent tissue lysates. Results: Single-linkage hierarchical clustering analysis reveals groups of autoantigens that are differentially expressed between normal lung tissue, carcinoid tumors, and adenocarcinomas. Adenocarcinoma tumor samples were significantly enriched for myositis (nominal p-value <0.001, false discovery rate (FDR) q-value 0.009) and SLE autoantigens (p-value 0.004, FDR 0.029). Scleroderma autoantigens were enriched in carcinoid tumors (p-value 0.003, FDR 0.053). Increased protein expression of the autoantigens Mi-2 and topoisomerase-1 in carcinoid tumors was confirmed by immunoblotting. Conclusions: This study reveals that autoantigens targeted in several autoimmune diseases are both transcribed and expressed at high levels in malignancies known to associate with those disorders. While autoantigens comprise only a small fraction of the total transcriptome, they are disproportionately expressed in tumors known to associate with autoimmunity, supporting the hyporthesis that autoimmunity to these proteins may arise via nascent anti-tumor responses.

No significant financial relationships to disclose.

A phase II trial of an adenovirus/PSA vaccine for prostate cancer

3065

Background: Our phase I adenovirus/PSA vaccine trial has proven the vaccine is safe. We are conducting a phase II clinical trial with two separate protocols for patients with recurrent or hormone-refractory prostate cancer assessing toxicity, immune responses, and change in PSA levels. Methods: In Protocol 1 men with recurrent prostate cancer after definitive initial treatment were randomized to arm A (vaccine injection alone at days 0, 30, and 60) or arm B (vaccine injection 14 days after initiation of androgen deprivation therapy). In Protocol 2 men with hormone-refractory disease receive the vaccine alone at days 0, 30, and 60. Each injection consists of 108 pfu of Ad/PSA vaccine suspended in a collagen matrix. All patients return at regular intervals for physical, chemical, radiologic, and immunologic evaluations. Twenty-five patients will be enrolled in arms A and B in Protocol 1 and 32 in Protocol 2. Results: To date 10 patients have completed 3 monthly injections and have been followed a median of 5 months. Median patient age is 70 years (range 61–84), and median enrollment PSA levels are 0.79 ng/ml (range 0.24–3.93) in Protocol 1 and 5.47 ng/ml (range 0.29–11.17) in Protocol 2. Preliminary results show 86% in both protocols demonstrating anti-PSA T cell responses above preinjection levels. 25% have stable serum PSA levels, 50% have decreased levels, and 25% have increased levels. 11% have stable serum prostatic acid phosphatase (PAP) levels, 56% have decreased levels, and 33% have increased levels. Conclusions: These early results from the first few months of this phase II trial demonstrate the induction of anti-PSA T-cell responses in a high percentage of the vaccinated patients and stabilization or declines in serum PSA and PAP levels. No serious vaccine-related toxicities have been identified.

No significant financial relationships to disclose.

State of the art: 3T imaging of the membranous labyrinth

This article reviews the anatomy of the membranous labyrinth and demonstrates the ability of high-resolution MR imaging at 3T to visualize the neurosensory epithelium by using the latest fast spin-echo techniques.

Osteopenia of prematurity: a national survey and review of practice

Premature infants are at significant risk of reduced bone mineral content (BMC) and subsequent osteopenia. There are currently no standard practices regarding screening, investigation or treatment of this condition. We present a case report and findings of a national survey of 36 level 2 and 3 neonatal units (72% response rate). The findings showed widely disparate practice regarding screening, prevention and treatment. We summarize the tests currently available for osteopenia and suggest guidelines for management of the at risk group.

CONCLUSION

Our survey confirms inconsistent practices regarding management of infants at risk of osteopenia of prematurity. Investigations and treatments available are summarized together with a guideline for management of this susceptible group of infants.

Effects of suburban land use on phosphorus fractions and speciation in the Upper Peruque Creek, Eastern Missouri

This field study was conducted to explore the spatial and seasonal changes in total phosphorus and fraction distribution in relation to land uses. Water samples were collected biweekly at four sampling locations, which represented different potential phosphorus sources along the Upper Peruque Creek in Eastern Missouri. Total phosphorus concentrations of > 0.8 mg/L appeared sporadically at site 2, downstream of a small community, with an average of 0.82 +/- 0.14 mg/L in fall. Particulate phosphorus accounted for approximately 80% of total phosphorus at all sampling sites, except for site 2, where approximately 50 to 75% of dissolved phosphorus was often observed. Approximately 71 and 85% of total phosphorus in the sediment was in the form of iron (III) phosphate at the headwaters and downstream sites, respectively; 29 and 15% was in the form of phytic acid at the two sites. Land uses affect the total phosphorus concentration and alternate phosphorus fraction and speciation in the creek.

Aquaporin 1 - a novel player in spinal cord injury

The role of water channel aquaporin 1 (AQP-1) in uninjured or injured spinal cords is unknown. AQP-1 is weakly expressed in neurons and gray matter astrocytes, and more so in white matter astrocytes in uninjured spinal cords, a novel finding. As reported before, AQP-1 is also present in ependymal cells, but most abundantly in small diameter sensory fibers of the dorsal horn. Rat contusion spinal cord injury (SCI) induced persistent and significant four- to eightfold increases in AQP-1 levels at the site of injury (T10) persisting up to 11 months post-contusion, a novel finding. Delayed AQP-1 increases were also found in cervical and lumbar segments, suggesting the spreading of AQP-1 changes over time after SCI. Given that the antioxidant melatonin significantly decreased SCI-induced AQP-1 increases and that hypoxia inducible factor-1alpha was increased in acutely and chronically injured spinal cords, we propose that chronic hypoxia contributes to persistent AQP-1 increases after SCI. Interestingly; AQP-1 levels were not affected by long-lasting hypertonicity that significantly increased astrocytic AQP-4, suggesting that the primary role of AQP-1 is not regulating isotonicity in spinal cords. Based on our results we propose possible novel roles for AQP-1 in the injured spinal cords: (i) in neuronal and astrocytic swelling, as AQP-1 was increased in all surviving neurons and reactive astrocytes after SCI and (ii) in the development of the neuropathic pain after SCI. We have shown that decreased AQP-1 in melatonin-treated SCI rats correlated with decreased AQP-1 immunolabeling in the dorsal horns sensory afferents, and with significantly decreased mechanical allodynia, suggesting a possible link between AQP-1 and chronic neuropathic pain after SCI.

New cutpoints to identify increased HER2 copy number: analysis of a large, population-based cohort with long-term follow-up

BACKGROUND

HER2 gene amplification and/or protein overexpression in breast cancer is associated with a poor prognosis and predicts response to anti-HER2 therapy. We examine the natural history of breast cancers in relationship to increased HER2 copy numbers in a large population-based study.

PATIENTS AND METHODS

HER2 status was measured by fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) in approximately 1,400 breast cancer cases with greater than 15 years of follow-up. Protein expression was evaluated with two different commercially-available antibodies.

RESULTS

We looked for subgroups of breast cancer with different clinical outcomes, based on HER2 FISH amplification ratio. The current HER2 ratio cut point for classifying HER2 positive and negative cases is 2.2. However, we found an increased risk of disease-specific death associated with FISH ratios of >1.5. An 'intermediate' group of cases with HER2 ratios between 1.5 and 2.2 was found to have a significantly better outcome than the conventional 'amplified' group (HER2 ratio >2.2) but a significantly worse outcome than groups with FISH ratios less than 1.5.

CONCLUSION

Breast cancers with increased HER2 copy numbers (low level HER2 amplification), below the currently accepted positive threshold ratio of 2.2, showed a distinct, intermediate outcome when compared to HER2 unamplified tumors and tumors with HER2 ratios greater than 2.2. These findings suggest that a new cut point to determine HER2 positivity, at a ratio of 1.5 (well below the current recommended cut point of 2.2), should be evaluated.

Noninvasive measurement of intra-aneurysmal pressure and flow pattern using phase contrast with vastly undersampled isotropic projection imaging

BACKGROUND AND PURPOSE

Currently, more reliable parameters to predict the risk of aneurysmal rupture are needed. Intra-aneurysmal pressure gradients and flow maps could provide additional information regarding the risk of rupture. Our hypothesis was that phase contrast with vastly undersampled isotropic projection reconstruction (PC-VIPR), a novel 3D MR imaging sequence, could accurately assess intra-aneurysmal pressure gradients in a canine aneurysmal model when compared with invasive measurements.

MATERIALS AND METHODS

A total of 13 surgically created aneurysms in 8 canines were included in this study. Pressure measurements were performed in the parent vessel, aneurysm neck, and 5 regions within the aneurysmal sac with a microcatheter. PC-VIPR sequence was used to obtain cardiac-gated velocity measurements in a region covering the entire aneurysm. The velocity and pressure gradient maps derived from the PC-VIPR data were then coregistered with the anatomic DSA images and compared with catheter measurements.

RESULTS

In 7 of the bifurcation aneurysms, the velocity flow maps demonstrated a recirculation flow pattern with a small neck-to-dome pressure gradient (mean, +0.5 mm Hg). In 1 bifurcation aneurysm, a flow jet extending from the neck to the dome with significantly greater pressure gradient (+50.2 mm Hg) was observed. All sidewall aneurysms had low flow in the sac with intermediate pressure gradients (mean, +8.3 mm Hg). High statistical correlation existed between PC-VIPR aneurysmal pressures and microcatheter pressure measurements (R = 0.82, P < .01).

CONCLUSION

PC-VIPR can provide anatomic as well as noninvasive quantitative and qualitative hemodynamic information in the canine aneurysm model. The PC-VIPR intra-aneurysmal pressure measurements correlated well with catheter measurements.

The genetic basis of the circadian clock: identification of frq and FRQ as clock components in Neurospora

Genetic approaches to the identification of clock components have succeeded in two model systems, Neurospora and Drosophila. In each organism, genes identified through screens for clock-affecting mutations (frq in Neurospora, per in Drosophila) have subsequently been shown to have characteristics of central clock components: (1) mutations in each gene can affect period length and temperature compensation, two canonical characteristics of circadian systems; (2) each gene regulates the timing of its own transcription in a circadian manner; and (3) in the case of frq, constitutively elevated expression will set the phase of the clock on release into normal conditions. Despite clear genetic and molecular similarities, however, the two genes are neither molecular nor temporal homologues. The timing of peak expression is distinct in the two genes, frq expression peaking after dawn and per expression peaking near midnight. Also, although expression of per from a constitutive promoter can rescue rhythmicity in a fly lacking the gene, constitutive expression of frq will not rescue rhythmicity in Neurospora frq-null strains, and in fact causes arrhythmicity when expressed in a wild-type strain. These data suggest that frq is and/or encodes a state variable of the circadian oscillator. Recent molecular genetic analyses of frq have shed light on the origin of temperature compensation and strongly suggest that this property is built into the oscillatory feedback loop rather than appended to it. It seems plausible that clocks are adjusted and reset through adjustments in central clock components such as frq, and, by extension, per.

Insufficient duration of venous thromboembolism prophylaxis after total hip or knee replacement when compared with the time course of thromboembolic events: findings from the Global Orthopaedic Registry

Patients who have undergone total hip or knee replacement (THR and TKR, respectively) are at high risk of venous thromboembolism. We aimed to determine the time courses of both the incidence of venous thromboembolism and effective prophylaxis. Patients with elective primary THR and TKR were enrolled in the multi-national Global Orthopaedic Registry. Data on the incidence of venous thromboembolism and prophylaxis were collected from 6639 THR and 8326 TKR patients. The cumulative incidence of venous thromboembolism within three months of surgery was 1.7% in the THR and 2.3% in the TKR patients. The mean times to venous thromboembolism were 21.5 days (sd 22.5) for THR, and 9.7 days (sd 14.1) for TKR. It occurred after the median time to discharge in 75% of the THR and 57% of the TKA patients who developed venous thromboembolism. Of those who received recommended forms of prophylaxis, approximately one-quarter (26% of THR and 27% of TKR patients) were not receiving it seven days after surgery, the minimum duration recommended at the time of the study. The risk of venous thromboembolism extends beyond the usual period of hospitalisation, while the duration of prophylaxis is often shorter than this. Practices should be re-assessed to ensure that patients receive appropriate durations of prophylaxis.

Incontinence in Malawi: Analysis of a proxy measure of vaginal fistula in a national survey

OBJECTIVE

To document the first effort to collect national lifetime prevalence data on vaginal fistulas and discern the usefulness of the measure.

METHODS

The 11,698 women successfully interviewed in the 2005 Malawi Demographic and Health Survey were asked whether they had ever experienced leakage of urine or stool from their vagina. Multivariate techniques were then used to determine factors associated with fistula symptoms.

RESULTS

The relationships between fistula symptoms and wealth and fistula symptoms and education were negative and monotonic. Rural women were 40% more likely than urban women to report fistula symptoms. Women who had experienced a stillbirth were 66% more likely to report the symptoms, and those who had experienced sexual violence were 71% more likely to report the symptoms. A crude fistula rate of 15.6 per 1000 live births was found for Malawi.

CONCLUSIONS

Survey methods may be used to capture the prevalence of vaginal fistula cases in a given country, but further work is needed to improve the sensitivity and specificity of the questions asked.