Fine-Scale Genetic Structure and Reproductive Biology of the Blueberry Pathogen Monilinia vaccinii-corymbosi

The fungus Monilinia vaccinii-corymbosi, a pathogen of Vaccinium spp., requires asexual and sexual spore production to complete its life cycle. A recent study found population structuring of M. vaccinii-corymbosi over a broad spatial scale in the United States. In this study, we examined fine-scale genetic structuring, temporal dynamics, and reproductive biology within a 125-by-132-m blueberry plot from 2010 to 2012. In total, 395 isolates of M. vaccinii-corymbosi were sampled from infected shoots and fruit to examine their multilocus haplotype (MLH) using microsatellite markers. The MLH of 190 single-ascospore isolates from 21 apothecia was also determined. Little to no genetic differentiation and unrestricted gene flow were detected among four sampled time points and between infected tissue types. Discriminant analysis of principal components suggested genetic structuring within the field, with at least K = 3 genetically distinct clusters maintained over four sampled time points. Single-ascospore progeny from eight apothecia had identical MLH and at least two distinct MLH were detected from 13 apothecia. Tests for linkage disequilibrium suggested that genetically diverse ascospore progeny were the product of recombination. This study supports the idea that the fine-scale dynamics of M. vaccinii-corymbosi may be complex, with genetic structuring, inbreeding, and outcrossing detected in the study area.

Biomarkers associated with severe hypoglycaemia and death in ACCORD

AIMS AND HYPOTHESIS

In patients with Type 2 diabetes, intensive glycaemic control is associated with hypoglycaemia and possibly increased mortality. However, no blood biomarkers exist to predict these outcomes. Using participants from the Action to Control Cardiovascular Risk in Diabetes (ACCORD) study, we hypothesized that insulin deficiency and islet autoantibodies in patients with clinically diagnosed Type 2 diabetes would be associated with severe hypoglycaemia and death.

METHODS

A nested case-control study design was used. A case (n = 86) was a participant who died with at least one episode of severe hypoglycaemia, defined as hypoglycaemia requiring assistance, at any point during ACCORD follow-up. A control (n = 344) was a participant who did not die and did not have severe hypoglycaemia during follow-up. Each case was matched to four controls (glycaemic intervention arm, race, age and BMI). Baseline insulin deficiency (fasting C-peptide ≤ 0.15 nmol/l) and islet autoantibodies [glutamic acid decarboxylase (GAD), tyrosine phosphatase-related islet antigen 2 (IA2), insulin (IAA) and zinc transporter (ZnT8)] were measured. Conditional logistic regression with and without adjustment for age, BMI and diabetes duration was used.

RESULTS

Death during ACCORD in those who experienced at least one episode of severe hypoglycaemia was associated with insulin deficiency [OR 4.8 (2.1, 11.1): P < 0.0001], GAD antibodies [OR 2.3 (1.1, 5.1): P = 0.04], the presence of IAA or baseline insulin use [OR 6.1 (3.5,10.7): P < 0.0001], which remained significant after adjusting for age, BMI, and diabetes duration. There was no significant association with IA2 or ZnT8 antibodies.

CONCLUSIONS

In patients with Type 2 diabetes, C-peptide or GAD antibodies may serve as blood biomarkers predicting higher odds of subsequent severe hypoglycaemia and death. (Clinical Trial Registry No: NCT00000620, www.clinicaltrials.gov for original ACCORD study).

Utilization of Axillary Surgery for Patients With Ductal Carcinoma In Situ: A Report From the National Cancer Data Base

BACKGROUND

This study evaluated the use of axillary surgery (AS), including sentinel lymph node biopsy (SLNB), for patients with ductal carcinoma in situ (DCIS) and the factors associated with its use. To determine whether utilization of SLNB is appropriate, predictors of SLNB performance were compared with factors predictive of tumor upstaging.

METHODS

The National Cancer Data Base was utilized to identify patients with American Joint Committee on Cancer (AJCC) clinical stage 0 breast cancer treated from 2004 to 2013. DCIS with microinvasion was excluded. Chi square tests and logistic regression were used to examine patient, tumor, and facility features associated with SLNB and tumor upstaging.

RESULTS

Of the 218,945 total patients, 155,093 (70.8 %) underwent lumpectomy, and 63,852 (29.2 %) underwent mastectomy. SLNB was performed for 19.0 % of lumpectomy patients and 63.5 % of mastectomy patients. Multivariate analysis for 2012-2013 demonstrated that estrogen receptor (ER)-negative and grade 3 tumors were more likely to be treated with SLNB in both groups. Tumor size was significant only for the lumpectomy patients who underwent one operation. Further, 22.8 % of lumpectomy patients and 18.7 % of mastectomy patients who underwent AS were upstaged compared with 1.8 % of lumpectomy and 3.6 % of mastectomy patients who did not undergo AS. Tumor upstaging was predicted by ER-negative status (odds ratio [OR] 2.99; 95 % confidence interval [CI] 2.76-3.24) but not by higher grade or larger tumor size.

CONCLUSIONS

Use of SLNB for DCIS is high with mastectomy, and nearly one fifth of the lumpectomy patients underwent SLNB. However, the performance of AS was strongly associated with the likelihood of upstaging in both groups, suggesting that surgical judgment plays an important role in this decision.

Toward a clinical application of ex situ boron neutron capture therapy for lung tumors at the RA-3 reactor in Argentina

PURPOSE

Many types of lung tumors have a very poor prognosis due to their spread in the whole organ volume. The fact that boron neutron capture therapy (BNCT) would allow for selective targeting of all the nodules regardless of their position, prompted a preclinical feasibility study of ex situ BNCT at the thermal neutron facility of RA-3 reactor in the province of Buenos Aires, Argentina. (l)-4p-dihydroxy-borylphenylalanine fructose complex (BPA-F) biodistribution studies in an adult sheep model and computational dosimetry for a human explanted lung were performed to evaluate the feasibility and the therapeutic potential of ex situ BNCT.

METHODS

Two kinds of boron biodistribution studies were carried out in the healthy sheep: a set of pharmacokinetic studies without lung excision, and a set that consisted of evaluation of boron concentration in the explanted and perfused lung. In order to assess the feasibility of the clinical application of ex situ BNCT at RA-3, a case of multiple lung metastases was analyzed. A detailed computational representation of the geometry of the lung was built based on a real collapsed human lung. Dosimetric calculations and dose limiting considerations were based on the experimental results from the adult sheep, and on the most suitable information published in the literature. In addition, a workable treatment plan was considered to assess the clinical application in a realistic scenario.

RESULTS

Concentration-time profiles for the normal sheep showed that the boron kinetics in blood, lung, and skin would adequately represent the boron behavior and absolute uptake expected in human tissues. Results strongly suggest that the distribution of the boron compound is spatially homogeneous in the lung. A constant lung-to-blood ratio of 1.3 ± 0.1 was observed from 80 min after the end of BPA-F infusion. The fact that this ratio remains constant during time would allow the blood boron concentration to be used as a surrogate and indirect quantification of the estimated value in the explanted healthy lung. The proposed preclinical animal model allowed for the study of the explanted lung. As expected, the boron concentration values fell as a result of the application of the preservation protocol required to preserve the lung function. The distribution of the boron concentration retention factor was obtained for healthy lung, with a mean value of 0.46 ± 0.14 consistent with that reported for metastatic colon carcinoma model in rat perfused lung. Considering the human lung model and suitable tumor control probability for lung cancer, a promising average fraction of controlled lesions higher than 85% was obtained even for a low tumor-to-normal boron concentration ratio of 2.

CONCLUSIONS

This work reports for the first time data supporting the validity of the ovine model as an adequate human surrogate in terms of boron kinetics and uptake in clinically relevant tissues. Collectively, the results and analysis presented would strongly suggest that ex situ whole lung BNCT irradiation is a feasible and highly promising technique that could greatly contribute to the treatment of metastatic lung disease in those patients without extrapulmonary spread, increasing not only the expected overall survival but also the resulting quality of life.

Ethical issues in surgical innovation

Innovation is responsible for most advances in the field of surgery. Innovative approaches to solving clinical problems have significantly decreased morbidity and mortality for many surgical procedures, and have led to improved patient outcomes. While innovation is motivated by the surgeon's expectation that the new approach will be beneficial to patients, not all innovations are successful or result in improved patient care. The ethical dilemma of surgical innovation lies in the uncertainty of whether a particular innovation will prove to be a "good thing." This uncertainty creates challenges for surgeons, patients, and the healthcare system. By its very nature, innovation introduces a potential risk to patient safety, a risk that may not be fully known, and it simultaneously fosters an optimism bias. These factors increase the complexity of informed consent and shared decision making for the surgeon and the patient. Innovative procedures and their associated technology raise issues of cost and resource distribution in the contemporary, financially conscious, healthcare environment. Surgeons and institutions must identify and address conflicts of interest created by the development and application of an innovation, always preserving the best interest of the patient above the academic or financial rewards of success. Potential strategies to address the challenges inherent in surgical innovation include collecting and reporting objective outcomes data, enhancing the informed consent process, and adhering to the principles of disclosure and professionalism. As surgeons, we must encourage creativity and innovation while maintaining our ethical awareness and responsibility to patients.

Operative risks associated with contralateral prophylactic mastectomy: a single institution experience

BACKGROUND

The purpose of this study was to determine if newly diagnosed breast cancer patients undergoing contralateral prophylactic mastectomy (CPM) experience more complications than patients undergoing unilateral mastectomy (UM).

METHODS

A total of 600 patients underwent either UM or CPM between January 2009 and March 2012 for unilateral breast cancer. Operative complications were classified as minor (aspirations, infection requiring antibiotics, partial flap and nipple necrosis, minor bleeding, delayed wound healing) or major (hematoma or seroma requiring operation, infection requiring rehospitalization, blood product transfusion, total flap or nipple loss, implant removal), mixed (both minor and major complications), or multiple. Chi-square and multivariate logistic regressions were used for the analysis.

RESULTS

Of the 600 patients, 391 (65 %) underwent UM and 209 (35 %) underwent CPM. Across all complication groups, there were significantly more complications in the CPM group versus the UM group (41.6 vs. 28.6 %, p = 0.001). Major complications alone were significantly greater in the CPM versus the UM group (13.9 vs. 4.1 %, p < 0.001). When adjusting for age, body mass index, smoking and diabetes history, AJCC stage, reconstruction, previous radiation therapy, and adjuvant therapy, CPM patients were 1.5 times more likely to have any complication (odds ratio [OR] 1.53; 95 % CI 1.04-2.25, p = 0.029) and 2.7 times more likely to have a major complication compared with UM patients (OR 2.66; 95 % CI 1.37-5.19, p = 0.004).

CONCLUSIONS

CPM patients have an increased risk of complications, especially major complications requiring rehospitalization or reoperation. These complications may influence patient and physician decisions to choose CPM.

Identifying information needs among children and teens living with haemophilia

Transitioning from one life stage to the next can be difficult, but for those living with a chronic condition, it can be even more challenging. Children and adolescents with haemophilia need help to manage transitions while dealing with the complications of their disorder. The National Haemophilia Foundation (NHF), headquartered in New York City, has an extensive information centre on bleeding disorders, but it was not clear how much material existed on the topic of transition. The objectives of this project were to (i) assess the availability of literature about transition for children and adolescents living with haemophilia, (ii) determine which transition issues were the most relevant and (iii) develop and test information products that would address those transition issues. An inventory of NHF's resources and an environmental scan over the Internet was performed. Focus groups were conducted to determine messaging. Video prototypes containing messages were created, tested by focus groups and revised. The literature search yielded limited information available on transition for children and adolescents with haemophilia. Results of the formative research indicated that adolescents wanted more information on sports participation and disclosure of their condition (e.g. to peers, teachers, coaches, health care providers). Video was found to be the preferred delivery format. Children and adolescents living with haemophilia need information to help them transition through life. As a result of this study, two educational products were produced, but several more are recommended to guide these individuals in making healthy transitions into adulthood.

Abstract B53: Analysis of Wnt signaling as a determinant of racial disparities in colorectal cancer outcomes

Purpose: While it is well-known that African American patients with colorectal cancer have worse survival outcomes than their Caucasian counterparts, the underlying mechanisms remain largely unidentified. We sought to determine whether differences exist in the molecular pathways which drive colorectal cancer between these two racial groups, with particular attention to genetic alterations and Wnt pathway activation. Although a majority of sporadic colorectal tumors have an APC mutation, the prognostic significance of β-catenin localization in colorectal cancer has yet to be determined definitively.

Experimental Design: We retrospectively examined 380 African American and Caucasian patients diagnosed with colorectal cancer at The University of Chicago Medical Center between 1992 and 2002. Tissue microarrays (TMAs) were constructed from the surgical pathology archive, and immunohistochemistry with β-catenin antibody (BD Biosciences) was performed. Two independent pathologists quantitatively analyzed the specimens for β-catenin localization; scoring was based on the intensity and percentage of positively stained cells in the nucleus, cytosol, and at the membrane. The tissues were previously analyzed for microsatellite instability (MSI) by genotyping the BAT25, BAT26, BAT40, D5S346, and BAXloci. Mutations in BRAF codon 600 and KRAS codons 12 and 13 were previously identified by direct sequencing. The molecular and immunohistochemical data were correlated with clinicopathological features, including age, race, gender, overall survival, anatomic location, AJCC stage, TNM stage, and receipt of chemotherapy. Statistical analyses were performed using Stata 11.0 (StataCorp).

Results: While there was no correlation between β-catenin localization and race, overall survival, anatomic location, or receipt of chemotherapy, tumor stage N1 was associated with higher cytosolic and nuclear scores than either N0 or N2 tumors (p = 0.01 and p = 0.001, respectively). Additionally, KRAS codon 13 mutation was significantly associated with low nuclear and cytosolic scores (p = 0.015 and p = 0.028). No association was found between β-catenin localization and KRAS codon 12 mutation, BRAF mutation, or MSI status. Importantly, after adjusting for demographic factors, pathologic factors, chemotherapy, molecular markers, and β-catenin localization, a significant difference in overall survival was demonstrated in African American vs. Caucasian patients, with an hazard ratio of 1.4 (95% CI 1.02-1.96, p = 0.036). The racial disparity was even greater in MSS/MSI-L tumors, with a 57% increased risk of death in African American patients compared to Caucasians (p = 0.011), even after controlling for prognostic factors.

Conclusion: Commonly used molecular markers, genetic alterations, and Wnt pathway status could not explain the significantly higher risk of death among African American patients with colorectal cancer in our cohort. Wnt pathway activation, as evidenced by high nuclear and cytosolic scores in N1 tumors, may be associated with early metastatic disease. KRAS codon 13 mutation was inversely related to Wnt pathway activation, suggesting that β-catenin localization has potential as a surrogate marker for this mutation if validated in larger studies. Overall, the results from this study highlight the need for additional targeted research to determine which biologic mechanisms are driving racial disparities in colorectal cancer outcomes.

Citation Format: Megan E. Miller, Rangesh Kunnavakkam, Galina Khramtsova, Andrey Khramtsov, Brooke Sylvester, Dezheng Huo, Olufunmilayo I. Olopade, Kathleen H. Goss. Analysis of Wnt signaling as a determinant of racial disparities in colorectal cancer outcomes. [abstract]. In: Proceedings of the Fifth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2012 Oct 27-30; San Diego, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2012;21(10 Suppl):Abstract nr B53.

Heel ultrasound can assess maintenance of bone mass in women with breast cancer

Postmenopausal women with early stage breast cancer are at increased risk for bone loss and fractures. Bisphosphonates can prevent bone loss, but little data are available on changes in bone mass assessed by heel quantitative ultrasound (QUS). Our objectives were to determine if (1) heel QUS would provide a reliable and accessible method for evaluation of changes in bone mass in women with breast cancer when compared with the current standard of bone mass measurement, dual-energy X-ray absorptiometry (DXA) and (2) oral risedronate could affect these changes. Eighty-six newly postmenopausal (up to 8 yr) women with nonmetastatic breast cancer were randomized to risedronate, 35 mg once weekly or placebo. Outcomes were changes in heel QUS bone mass measurements and conventional DXA-derived bone mineral density (BMD). Over 2 yr, bone mass assessed by heel QUS remained stable in women on risedronate, whereas women on placebo had a 5.2% decrease (p ≤ 0.05) in heel QUS bone mass. Both total hip BMD and femoral neck BMD assessed by DXA decreased by 1.6% (p ≤ 0.05) in the placebo group and remained stable with risedronate. Spine BMD remained stable in both groups. Heel QUS was moderately associated with BMD measured by DXA at the total hip (r=0.50), femoral neck (r=0.40), and spine (r=0.46) at baseline (all p ≤ 0.001). In conclusion, risedronate helps to maintain skeletal integrity as assessed by heel QUS for women with early stage breast cancer. Heel QUS is associated with DXA-derived BMD at other major axial sites and may be used to follow skeletal health and bone mass changes in these women.

Posttraumatic stress disorder in DSM-5: estimates of prevalence and symptom structure in a nonclinical sample of college students

We empirically investigated recent proposed changes to the posttraumatic stress disorder (PTSD) diagnosis for DSM-5 using a non-clinical sample. A web survey was administered to 585 college students using the Stressful Life Events Screening Questionnaire to assess for trauma exposure but with additions for the proposed traumatic stressor changes in DSM-5 PTSD. For the 216 subjects endorsing previous trauma exposure and nominating a worst traumatic event, we administered the original PTSD Symptom Scale based on DSM-IV PTSD symptom criteria and an adapted version for DSM-5 symptoms, and the Center for Epidemiological Studies-Depression Scale. While 67% of participants endorsed at least one traumatic event based on DSM-IV PTSD's trauma classification, 59% of participants would meet DSM-5 PTSD's proposed trauma classification. Estimates of current PTSD prevalence were .4-1.8% points higher for the DSM-5 (vs. the DSM-IV) diagnostic algorithm. The DSM-5 symptom set fit the data very well based on confirmatory factor analysis, and neither symptom set's factors were more correlated with depression.

Intracochlear schwannoma presenting as diffuse cochlear enhancement: diagnostic challenges of a rare cause of deafness

Intracochlear schwannoma is a rare, treatable, cause of unilateral hearing loss. Due to the small size, position, and variable clinical and imaging features, diagnosis presents a significant challenge and is often delayed. We present a case of a patient with an intracochlear schwannoma presenting as a diffuse enhancement of the cochlea, mimicking an infectious or inflammatory process. The absence of focal nodularity in this lesion on multiple high-resolution MRI examinations led to a delay of over 3 years from the patient's initial presentation to surgical diagnosis. Clinical history and examination, imaging features, pathologic findings, and surgical management options are described.

Expression and characterization of a multivalent human respiratory syncytial virus protein

Respiratory syncytial virus (RSV) has been recognized as one of the most common causes of severe respiratory tract infection in infants worldwide. As yet, a safe and effective vaccine has not been developed to protect humans from RSV. The F and G surface proteins have been widely investigated due to their potential to induce protective immunity. In addition, the M2 protein has been shown to be important in inducing a T-cell response. Our project involved the cloning of the immunodominant regions of the RSV F, M2 and G proteins into a bacterial vector, pET-32a (+). The recombinant RFM2G protein was expressed in Escherichia coli and purified using His Bind columns. The purified rRFM2G protein was analyzed by polyacrylamide gel electrophoresis and Western blotting. The predicted structure of the recombinant protein built by the Swiss PDB Viewer program suggested a rod shape with a distinct swollen head and neck which was confirmed by transmission electron microscopy and atomic force microscopy. BALB/c female mice were immunized with either RSV, rRFM2G alone, or rRFM2G in combination with flagellin as a mucosal adjuvant. Serum was collected on days 0, 14, 28 and 49 to assess the immune response by Enzyme-linked immunosorbent assay. Intranasal immunization of mice with the rRFM2G protein yielded significantly high serum IgG titers. Co-administration of the rRFM2G protein with flagellin did not augment the serum antibody response.

HIV risk exposure of injecting drug users in Sydney

One thousand two hundred and forty-five Sydney injecting drug users (IDUs) were interviewed by questionnaire in 1989 to determine demographic and behavioural characteristics. One-sixth (16.7%) were considered to be at low risk of HIV from either needle sharing or sexual transmission as they had either never shared injecting equipment, or had not shared for years, or cleaned their injecting equipment effectively on 100% of the occasions when they did share; and were either celibate or monogamous or, if they had multiple partners, had not had unsafe sex in the previous 6 months. Over half (50.7%) had either unsafe injecting or sexual behaviour with the remaining third (32.6%) engaging in both unsafe injecting and sexual practises. Women were more at risk from sharing injection equipment than men but men were more at risk from sexual transmission than women. Increasing age was associated with greater likelihood of safer sex but age had no effect on injecting practises. There was no relationship between unsafe injecting and sexual practises. Amphetamine use was associated with low risk injecting practises while heroin use was associated with low risk sexual transmission. These findings indicate appreciable residual risk behaviour sufficient to allow for at least a slow diffusion of HIV among injecting drug users.

Predictors of unsafe injecting drug use

This paper reports on the incidence of unsafe injecting and the factors which influence this practice in a sample of 1245 Sydney injecting drug users (IDUs). Using a needle and syringe after someone else at some time in the last six months was reported in 41.6% of the sample. Taking into account those who claimed always to clean used needles with virucidal methods, 32.9% had placed themselves at risk of HIV infection from shared needles in the six months prior to interview.Seven factors were predictive of unsafe behaviour. These were (a) the amount spent per week on drugs, (b) the number of times a single needle was used prior to disposal, (c) having shared with a person who is now HIV infected, (d) having a regular sexual partner, (e) the proportion of times high, stoned or drunk when injecting, (f) being part of a group that injects together and (g) having been in prison.

Skeletal health after continuation, withdrawal, or delay of alendronate in men with prostate cancer undergoing androgen-deprivation therapy

PURPOSE

Androgen-deprivation therapy (ADT) for prostate cancer is associated with bone loss and osteoporotic fractures. Our objective was to examine changes in bone density and turnover with sustained, discontinued, or delayed oral bisphosphonate therapy in men receiving ADT.

PATIENTS AND METHODS

A total of 112 men with nonmetastatic prostate cancer receiving ADT were randomly assigned to alendronate 70 mg once weekly or placebo in a double-blind, partial-crossover trial with a second random assignment at year 2 for those who initially received active therapy. Outcomes included bone mineral density and bone turnover markers.

RESULTS

Men initially randomly assigned to alendronate and randomly reassigned at year 2 to continue had additional bone density gains at the spine (mean, 2.3% +/- 0.7) and hip (mean, 1.3% +/- 0.5%; both P < .01); those randomly assigned to placebo in year 2 maintained density at the spine and hip but lost (mean, -1.9% +/- 0.6%; P < .01) at the forearm. Patients randomly assigned to begin alendronate in year 2 experienced improvements in bone mass at the spine and hip, but experienced less of an increase compared with those who initiated alendronate at baseline. Men receiving alendronate for 2 years experienced a mean 6.7% (+/- 1.2%) increase at the spine and a 3.2% (+/- 1.5%) at the hip (both P < .05). Bone turnover remained suppressed.

CONCLUSION

Among men with nonmetastatic prostate cancer receiving ADT, once-weekly alendronate improves bone density and decreases turnover. A second year of alendronate provides additional skeletal benefit, whereas discontinuation results in bone loss and increased bone turnover. Delay in bisphosphonate therapy appears detrimental to bone health.

Estimation of bone strength from pediatric radiographs of the forearm

OBJECTIVE

Bone strength is a function of both material and architectural properties. However, bone geometry or architecture, which determines the distribution of bone, is an underappreciated determinant of bone strength. The aim of the study was to evaluate the contribution of only architecture to bone strength.

METHODS

We used 2-D (planar) geometric information from radiographs of human radii to construct 3-D finite-element models. To transition from 2-D to 3-D (volume) space, we assumed that all bone cross-sections were elliptical in shape. The finite-element models were subjected to cantilever loading to determine the locations in the bone with the highest propensity to fracture (points of maximum stress). The finite-element-analysis results of the models generated from radiographs of both normal (18) and temporary-brittle-bone-disease (11) infants were subjected to a receiver operating curve analysis. The area under the receiver operating curve was used to evaluate the power of a given bone-strength indicator in segregating the two populations. The actual choice of the material properties (Young's modulus or Poisson's ratio) was not critical for this study, since the finite element analyses were designed to capture the difference in the bone strength of the two populations only based on their architecture. Therefore, the material properties were assumed to be the same in both the normal and TBBD populations.

RESULTS

The area under the curve of the bending load required to cause fracture among the two populations was 0.82. Other bone-strength indicators, such as average section modulus, cortical thickness and bone length, were associated with an area under the curve of 0.75, 0.73 and 0.63, respectively.

CONCLUSION

The results of the finite-element-analysis suggest that the temporary-brittle-bone-disease population has an altered bone geometry, which increases susceptibility to fracture under normal bending loads.

Physical function in men with prostate cancer on androgen deprivation therapy

BACKGROUND AND PURPOSE

Androgen deprivation therapy (ADT) has become an increasingly standard intervention for both early and advanced stages of prostate cancer; however, decreased physical function and hypogonadism have been reported in men receiving ADT. The objectives of this study were: (1) to determine whether ADT (and hypogonadism) resulted in decreased strength and mobility and (2) to examine the effect of ADT on an associated test of cognitive and motor function by assessing visuomotor performance.

SUBJECTS AND METHODS

Physical function, walking speed, visuomotor performance, gonadal status, body composition, and Comorbidity Disease Index (CMDI) scores were assessed in a cohort of 100 participants that included: (1) men with prostate cancer who were not on ADT, (2) men with prostate cancer who were on short-term ADT (<6 months), (3) men with prostate cancer who were on long-term ADT (> or =6 months), and (4) control subjects who did not have prostate cancer.

RESULTS

Walking speed varied significantly across the 4 groups, even after adjusting for age, CMDI, and percentage of body fat. Age and CMDI were significantly associated with measurements of physical performance. Adjusted for covariates, men on long-term ADT walked 0.18 m/s slower than the control subjects. Physical function also varied significantly across the 4 groups. Androgen deprivation therapy did not have a significant effect on visuomotor performance.

DISCUSSION AND CONCLUSION

The results suggest that ADT has a significant effect on walking speed and physical performance in men with prostate cancer.

First Report of Iris yellow spot virus on Onion (Allium cepa) in Texas

Iris yellow spot virus (IYSV; family Bunyaviridae, genus Tospovirus) has emerged as a potentially devastating and widespread virus of onion. IYSV was first reported in the United States from Idaho in 1993 and has since spread to many of the onion-producing areas (1). In South America, the most recent reports of the virus on onion were from Peru and Chile (2,4). In 2005, onion plants in Uvalde County, Texas exhibited necrotic lesions on leaves typical of IYSV and disease incidence approached 100% in some fields with yield loss and quality problems. Five of six plants tested were positive for IYSV with double antibody sandwich-enzyme linked immunosorbent assay (DAS-ELISA; Agdia Inc., Elkhart, IN). In 2006, similar lesions were observed on onion plants in Uvalde County and approximately 400 km south in Hidalgo and Cameron counties. Infection points generally started as a single plant near the edge of fields and spread to plants in a 3- to 4-m area after 1 to 2 weeks. Early-season disease incidence was low in onions grown for bulbs and transplants, <10% in 2006. Disease incidence increased in some fields until the crop was harvested. Leaves of symptomatic plants were tested for IYSV and Tomato spotted wilt virus (TSWV) using DAS-ELISA, and 18 of 23 samples from the Hidalgo County area and 12 of 21 samples from the Uvalde County area were positive for IYSV. All samples tested for TSWV from these counties were negative. Virus infection in some ELISA-positive plants was verified by reverse transcription-polymerase chain reaction (RT-PCR) using primers derived from the small RNA of IYSV. The primers flanked the IYSV nucleocapsid (N) gene (5'-TAA AAC AAA CAT TCA AAC AA-3' and 5'-CTC TTA AAC ACA TTT AAC AAG CAC-3' (3). RT-PCR gave a PCR product of expected size (approximately 1.2 kb). The DNA amplicon was cloned and sequenced (GenBank Accession No. DQ658242). Nucleotide sequence analysis confirmed the identity of the amplicon as that of IYSV N gene and sequence comparisons with known IYSV N gene sequences showed 95 to 98% sequence identity. The primary vector of IYSV, onion thrips (Thrips tabaci), is a widespread and destructive pest of onion in south Texas. The year-to-year incidence of IYSV and the severity of the disease will probably depend on the onion thrips population levels. Bulb yield reduction could be severe during years with high thrips populations. More research is needed to determine the impact of IYSV on bulb yield in Texas, the relationship between IYSV incidence and T. tabaci population levels, and oversummering hosts. To our knowledge, this is the first known report of IYSV in Texas. References: (1) D. H. Gent et al. Plant Dis. 88:446, 2004, (2) S. W. Mullis et al. Plant Dis. 90:377, 2006, (3) H. Pappu et al. Arch. Virol. 151:1015, 2006. (4) M. Rosales et al. Plant Dis. 89:1245, 2005.

First Report of Rust Caused by Phakopsora pachyrhizi on Soybean and Kudzu in Texas

The Asian soybean rust fungus, Phakopsora pachyrhizi H. Sydow & Sydow, was found on a 0.4-ha patch of kudzu (Pueraria lobata) near Dayton (Liberty County) in East Texas on November 2, 2005. Nearly 100% of the 300 leaflets examined were diseased with severity ranging from 5 to >100 lesions per leaflet. Eleven soybean fields as much as 20 km away were scouted and no infected plants were found. Asian soybean rust was also found on a 0.4-ha field of soybean (Glycine max cv. Vernal) on February 14, 2006 at the Texas A&M Agricultural Experiment Station in Weslaco (Hidalgo County) in the Lower Rio Grande Valley (LRGV) of Texas. Disease incidence was 100% (severity ranging from 5 to >100 lesions per leaflet) on 50 younger plants with green leaves along the edges of the field, whereas most of the plants in this field had senesced. These plants were not symptomatic and were at the R6 stage (full seed) when this field was previously scouted on December 19, 2005. Lesions on leaflets of kudzu and soybean were small and angular with erumpent uredinia typical of P. pachyrhizi. Urediniospores were ovoid or globose, hyaline, and measured 25 to 30 × 14 to 21 μm. Leaf samples with pustules were positive for P. pachyrhizi using enzyme-linked immunosorbent assay (ELISA) (Envirologix, Portland, ME). Morphological and polymerase chain reaction (PCR) identification of P. pachyrhizi from kudzu and soybean samples were confirmed by the USDA-APHIS-PPQ NIS and CPHST laboratories in Beltsville, MD as previously described (2). The kudzu in East Texas is not likely to support overwintering of the pathogen because it usually dies back during the winter. Leaves at this site were dead by January 17, 2006. This is the southernmost infestation of kudzu in Texas known to us. In contrast, the LRGV has a subtropical climate that would favor year-round survival of the fungus (3). This area, where 120 to 160 ha of soybeans are grown, may be a source of inoculum for soybean rust epidemics in the Midwest. Spore movement would follow the same pattern as seen with cereal rusts (1). However, soybeans are typically absent from the LRGV between late December and early March, so survival of the fungus during this interval would require other hosts. Regardless of whether the fungus overwinters here, or moves in from elsewhere, the LRGV spring crop could serve as an early indicator of a potential rust epidemic. References: (1) M. G. Eversmeyer and C. L. Kramer. Annu. Rev. Phytopathol. 38:491, 2000. (2) J. M. Mullen et al. Plant Dis. 90:112, 2006. (3) S. Pivonia et al. Plant Dis. 89:678, 2005.

Benzo-[a]-pyrene increases invasion in MDA-MB-231 breast cancer cells via increased COX-II expression and prostaglandin E2 (PGE2) output

Benzo-[a]-pyrene (B[a]P), a carcinogenic component of cigarette smoke, has been shown to increase both COX-II expression and prostaglandin output in vascular smooth muscle and oral epithelial cells. In addition, invasive breast cancer cells have been reported to over express COX-II and PGE(2). Therefore, the objective of this study was to quantify the effect of increasing B[a]P concentrations on COX-II expression, PGE(2) output, and invasion using MDA-MB-231 cells, an invasive estrogen unresponsive breast cancer cell line. B[a]P significantly increased invasion in MDA-MB-231 cells at concentrations greater than 4 x 10(-8) M. Treatment of MDA-MB-231 cells with Vomitoxin (a selective COX-II inducer) enhanced invasion whereas co-treatment with NS398 (a selective COX-II inhibitor) attenuated B[a]P-induced invasion in MDA-MB-231 cells. Immunohistochemical staining and Western blots demonstrated a significant B[a]P treatment-induced increase in both the number of COX-II immunopositive MDA-MB-231 cells and COX-II protein levels. Moreover, B[a]P-treatment induced a profound (46 fold) increase in PGE(2) production by MDA-MB-231 cells. The aryl hydrocarbon receptor (AhR) antagonists resveratrol (RES) and alpha-naphthaflavone (alpha-NF) had no effect on their own, whereas B[a]P-induced invasion was significantly inhibited by co-treatment with RES and alpha-NF. Our data demonstrate that B[a]P-induced changes in invasion are mediated through augmented COX-II expression and PGE(2) production involving an AhR regulated pathway. Moreover, these results suggest a potential role for the AhR signalling pathway in breast cancer invasion.

Suppressor of cytokine signaling-2 modulates the fibrogenic actions of GH and IGF-I in intestinal mesenchymal cells

Growth hormone (GH) and IGF-I play important roles in wound healing during intestinal injury and inflammation, but there is also indirect evidence that locally expressed IGF-I may act to induce excessive collagen deposition, which can lead to intestinal fibrosis. Factors that dictate the balance between normal wound healing and excessive healing responses are unknown. Using RNase protection assay and in situ hybridization, we determined whether GH and/or IGF-I increase type I collagen deposition in the intestine of rats fed by total parenteral nutrition (TPN), a feeding modality used for many patients following intestinal surgery and resection. We also used an in vitro model system to confirm our in vivo effects and to directly evaluate the relative potency of GH and IGF-I on DNA synthesis and collagen deposition in intestinal myofibroblasts. Both GH and IGF-I stimulated collagen production in vivo and in vitro, and IGF-I, but not GH, stimulated DNA synthesis in vitro. In collagen production, GH was less potent than IGF-I. Suppressors of cytokine signaling (SOC) are cytokine-inducible proteins that negatively feedback to inhibit the actions of cytokines and we recently found that GH selectively upregulates SOC-2 in the intestine of TPN-fed rats. We examined whether SOC-2 may be responsible for the difference in magnitude of action of GH and IGF-I on collagen accumulation. GH, but not IGF-I, induced SOC-2 in isolated myofibroblasts, and overexpression of SOC-2 led to a suppression of GH- and IGF-I-induced collagen accumulation. SOC-2 null mice infused with IGF-I showed greater collagen gene expression compared with wild-type (WT) mice. Myofibroblasts isolated from SOC-2 null mice showed increased IGF-I-stimulated DNA synthesis compared with WT cells. Taken together, these findings suggest that SOC-2 induced by GH may play an important role in suppressing collagen accumulation and mesenchymal cell proliferation induced by GH or GH-induced IGF-I, providing a mechanism for the differing potencies of GH and IGF-I on intestinal mesenchyme and collagen synthesis.

Implantable self-powered detector for on-line determination of neutron flux in patients during NCT treatment

A novel system to determine thermal neutron flux in real time during NCT treatments was developed in the National Atomic Energy Commission of Argentina. The system is based on a special self-powered detector that can be implanted in patients owing to its small size and biocompatibility. High voltage is not required to operate this kind of detectors, which is a considerable advantage in terms of medical uses. By choosing the appropriate materials, it was possible to obtain a prototype with thermal neutron sensitivity providing for an adequate signal level in typical NCT thermal fluxes. It was also possible to minimize gamma response in order to neglect its contribution.

Cellular basis of diabetic nephropathy: III. In vitro GLUT1 mRNA expression and risk of diabetic nephropathy in type 1 diabetic patients

AIMS/HYPOTHESIS

Altered glucose transporter expression has been implicated in the pathogenesis of diabetic nephropathy. There is increasing evidence that genetic factors convey risk of, or protection from, diabetic nephropathy and that the behaviour of cultured skin fibroblasts from type 1 diabetic patients may reflect these genetic influences. This study aimed to compare GLUT1 mRNA expression levels in skin fibroblasts from type 1 diabetic patients with either rapid ("fast-track", n=25) or slow ("slow-track", n=25) development of diabetic nephropathy and from non-diabetic normal control subjects (controls, n=25).

METHODS

Skin fibroblasts were cultured in Dulbecco's Modified Eagle's Medium with 25 mmol/l glucose for 36 h. Total RNA was isolated, and GLUT1 mRNA levels were estimated by microarray analysis and RT-PCR.

RESULTS

Levels of GLUT1 mRNA expression in skin fibroblasts from "slow-track" patients were greater than those from "fast-track" patients (p=0.02), as initially detected by microarray. GLUT1 mRNA expression levels were confirmed by RT-PCR to be higher in skin fibroblasts from "slow-track" patients (4.59+/-2.04) than in those from "fast-track" patients (3.34+/-1.2, p=0.02), and were also higher than in skin fibroblasts from control subjects (3.52+/-1.66, p=0.03). There was no statistically significant difference between levels of expression in the "fast-track" patients and the control subjects.

CONCLUSIONS/INTERPRETATION

This finding is consistent with the presence of cellular protection factors against diabetic nephropathy in the "slow-track" patients. These factors could be associated with the regulation of the GLUT1 pathway and may be genetically determined.