Attention challenges in Kabuki syndrome

BACKGROUND

Understanding the specific neurobehavioural profile of rare genetic diseases enables clinicians to provide the best possible care for patients and families, including prognostic and treatment advisement. Previous studies suggested that a subset of individuals with Kabuki syndrome (KS), a genetic disorder causing intellectual disability and other neurodevelopmental phenotypes, have attentional deficits. However, these studies looked at relatively small numbers of molecularly confirmed cases and often used retrospective clinical data instead of standardised assessments.

METHODS

Fifty-five individuals or caregivers of individuals with molecularly confirmed KS completed assessments to investigate behaviour and adaptive function. Additionally, information was collected on 23 unaffected biological siblings as controls.

RESULTS

Attention Problems in children was the only behavioural category that, when averaged, was clinically significant, with the individual scores of nearly 50% of the children with KS falling in the problematic range. Children with KS scored significantly higher than their unaffected sibling on nearly all behavioural categories. A significant correlation was found between Attention Problems scores and adaptive function scores (P = 0.032), which was not explained by lower general cognitive ability.

CONCLUSIONS

We found that the rates of children with attentional deficits are much more elevated than would be expected in the general population, and that attention challenges are negatively correlated with adaptive function. When averaged across KS participants, none of the behavioural categories were in the clinically significant range except Attention Problems for children, which underscores the importance of clinicians screening for attention deficit hyperactivity disorder (ADHD) in children with KS.

Rift valley fever outbreak in Sembabule District, Uganda, December 2020

BACKGROUND

Rift Valley Fever (RVF) is a viral zoonosis that can cause severe haemorrhagic fevers in humans and high mortality rates and abortions in livestock. On 10 December 2020, the Uganda Ministry of Health was notified of the death of a 25-year-old male who tested RVF-positive by reverse-transcription polymerase chain reaction (RT-PCR) at the Uganda Virus Research Institute. We investigated to determine the scope of the outbreak, identify exposure factors, and institute control measures.

METHODS

A suspected case was acute-onset fever (or axillary temperature > 37.5 °C) and ≥ 2 of: headache, muscle or joint pain, unexpected bleeding, and any gastroenteritis symptom in a resident of Sembabule District from 1 November to 31 December 2020. A confirmed case was the detection of RVF virus nucleic acid by RT-PCR or serum IgM antibodies detected by enzyme-linked immunosorbent assay (ELISA). A suspected animal case was livestock (cattle, sheep, goats) with any history of abortion. A confirmed animal case was the detection of anti-RVF IgM antibodies by ELISA. We took blood samples from herdsmen who worked with the index case for RVF testing and conducted interviews to understand more about exposures and clinical characteristics. We reviewed medical records and conducted an active community search to identify additional suspects. Blood samples from animals on the index case's farm and two neighbouring farms were taken for RVF testing.

RESULTS

The index case regularly drank raw cow milk. None of the seven herdsmen who worked with him nor his brother's wife had symptoms; however, a blood sample from one herdsman was positive for anti-RVF-specific IgM and IgG. Neither the index case nor the additional confirmed case-patient slaughtered or butchered any sick/dead animals nor handled abortus; however, some of the other herdsmen did report high-risk exposures to animal body fluids and drinking raw milk. Among 55 animal samples collected (2 males and 53 females), 29 (53%) were positive for anti-RVF-IgG.

CONCLUSIONS

Two human RVF cases occurred in Sembabule District during December 2020, likely caused by close interaction between infected cattle and humans. A district-wide animal serosurvey, animal vaccination, and community education on infection prevention practices campaign could inform RVF exposures and reduce disease burden.

An outbreak of malaria caused by increase in malaria breeding sites in swamps

On 10^th June 2019, routine analysis of malaria surveillance data at the National Malaria Control Division, Ministry of Health in Uganda revealed that there was an unusual increase in the number of malaria cases reported in the Oyam District. On 11^th June 2019, the District Health Officer in Oyam District convened a meeting with the District Health Team (DHT) in which the District Biostatistician confirmed that the number of malaria cases had indeed exceeded the upper limit, starting in epidemic week 24 (approximately the week of June 10). The District Health Officer issued a formal request to the Ministry of Health for assistance in dealing with the malaria outbreak in Oyam. Two field epidemiology residents were assigned to work with the District Health Team to investigate the outbreak. The residents followed the steps in conducting vector borne disease outbreak investigations including preparation for field work, establishment of the existence of an outbreak by analyzing surveillance data, descriptive data analysis, hypothesis generation, conducting environmental and entomological assessments, conducting analytic studies with a focus on the utility of retrospective cohort studies as well as reporting findings. This case study teaches trainees in Field Epidemiology and Laboratory Training Programs, public health students, public health workers who are interested or who may participate in vector borne disease outbreak investigation and response.

Delayed outbreak detection: a wake-up call to evaluate a surveillance system

During May, 83 of the 120 districts in Uganda had reported malaria cases above the upper limit of the normal channel. Across all districts, cases had exceeded malaria normal channel upper limits for an average of six months. Yet no alarms had been raised! Starting in 2000, Uganda adopted the World Health Organization (WHO) Integrated Disease Surveillance and Response (IDSR) strategy for disease reporting, including for malaria. Even early on, however, it was unclear how effectively IDSR and DHIS2 were being used in Uganda. Outbreaks were consistently detected late, but the underlying cause of the late detection was unclear. Suspecting there might be gaps in the surveillance system that were not immediately obvious, the Uganda FETP was asked to evaluate the malaria surveillance system in Uganda. This case study teaches trainees in Field Epidemiology and Laboratory Training Programs, public health students, public health workers who may participate in evaluation of public health surveillance systems, and others who are interested in this topic on reasons, steps, and attributes and uses the surveillance evaluation approach to identify gaps and facilitates discussion of practical solutions for improving a public health surveillance system.

Relationship of depth of invasion to survival outcomes and patterns of recurrence for T3 oral tongue squamous cell carcinoma

INTRODUCTION

Current research is elucidating how the addition of depth of invasion (DOI) to the 8th edition of the American Joint Committee on Cancer (AJCC) TNM staging for oral cavity squamous cell carcinoma influences its prognostic accuracy. However, there is limited research on survival in pT3N0M0 oral tongue SCC (OTSCC) patients when stratifying by DOI.

OBJECTIVES

Determine 5-year overall survival (OS), and cancer-specific survival (CSS) for patients with pT3N0M0 oral OTSCC based on shallow DOI (<10 mm) and deep DOI (10-20 mm).

METHODS

Retrospective review involving three tertiary care cancer centers in North America. cT3N0M0 OTSCC patients receiving primary surgical treatment from 2004 to 2018 were identified. Inclusion: age > 18 years old and confirmation of pT3N0M0 OTSCC on surgical pathology. Exclusion: patients undergoing palliative treatment or previous head and neck surgery/radiotherapy. Analysis comprised two groups: shallow pT3 (tumor diameter > 4 cm, DOI < 10 mm) and deep pT3 (DOI 10 mm-20 mm).

RESULTS

One hundred and four patients with pT3N0M0 OTSCC were included. Mean age was 59.1 years (range: 18-80.74). Age, gender, and Charlson Comorbidity Index were similar between the two groups (p > 0.05). Recurrence, LVI, PNI, and positive margins were more common in deep T3 tumors (P < 0.05). 5-year OS (50% vs 26%, p = 0.006) and CSS (72% vs 24%, p = 0.005) were worse in deep pT3 tumors. Deep pT3 disease was an independent predictor of OS (p = 0.004) and CSS (p = 0.01) on Cox-Regression analysis.

CONCLUSION

DOI is an independent predictor of poor survival in pT3N0M0 OTSCC patients. Consideration should be given to escalating adjuvant therapy for deep pT3N0M0 OTSCC patients.

Associations between birth size and later height from infancy through adulthood: An individual based pooled analysis of 28 twin cohorts participating in the CODATwins project

BACKGROUND

There is evidence that birth size is positively associated with height in later life, but it remains unclear whether this is explained by genetic factors or the intrauterine environment.

AIM

To analyze the associations of birth weight, length and ponderal index with height from infancy through adulthood within mono- and dizygotic twin pairs, which provides insights into the role of genetic and environmental individual-specific factors.

METHODS

This study is based on the data from 28 twin cohorts in 17 countries. The pooled data included 41,852 complete twin pairs (55% monozygotic and 45% same-sex dizygotic) with information on birth weight and a total of 112,409 paired height measurements at ages ranging from 1 to 69 years. Birth length was available for 19,881 complete twin pairs, with a total of 72,692 paired height measurements. The association between birth size and later height was analyzed at both the individual and within-pair level by linear regression analyses.

RESULTS

Within twin pairs, regression coefficients showed that a 1-kg increase in birth weight and a 1-cm increase in birth length were associated with 1.14-4.25 cm and 0.18-0.90 cm taller height, respectively. The magnitude of the associations was generally greater within dizygotic than within monozygotic twin pairs, and this difference between zygosities was more pronounced for birth length.

CONCLUSION

Both genetic and individual-specific environmental factors play a role in the association between birth size and later height from infancy to adulthood, with a larger role for genetics in the association with birth length than with birth weight.

Abstract P4-12-04: Breast cancer subtype, age and lymph node status as predictors of local recurrence following breast-conserving therapy

Purpose/Objectives: Advances in breast-conserving therapy (BCT) have yielded local control rates comparable or superior to those of mastectomy. Here, we sought to identify risk factors associated with isolated local recurrence (LR) following BCT.

Materials/Methods: This study included a multi-institutional cohort of 2,233 consecutive breast cancer patients who underwent BCT between 1998 and 2007. Patient characteristics and disease parameters were stratified by age, subtype and nodal status. Biologic subtype was approximated by receptor status and tumor grade. No patients received HER2/neu-directed therapy. The association of clinicopathologic features with LR was evaluated using Cox proportional hazards regression models.

Results: At a median follow-up of 106 months, 69 LR events (3.1%) were observed. Among the overall cohort, 10-year freedom from LR was 95.9%. On univariate Cox regression analysis, risk factors associated with LR included subtype other than luminal A (hazard ratio [HR] for luminal B = 3.01, HER2 = 6.29, triple negative [TNBC] = 4.72; p&lt;0.001 for each), younger age (HR of oldest versus youngest quartile = 0.43; p=0.005), regional lymph node involvement (HR for 4-9 involved nodes = 3.04; &gt;9 nodes = 5.82; p&lt;0.01 for each), positive resection margins (HR = 2.43; p=0.005), and high-grade disease (HR = 5.37; p &lt;0.001). Presence of LVI (HR = 1.56; p=0.06) or 1-3 involved nodes (HR = 1.55; p=0.07) approached significance. Multivariate Cox regression demonstrated an association with LR among those with non-luminal A subtypes (HR for luminal B = 2.64, HER2 = 5.42, TNBC = 4.32; p&lt;0.001 for each), younger age (HR for age &gt;50 = 0.56; p=0.01), and any nodal disease (HR=1.06 per involved node; p&lt;0.004).

Conclusions: BCT yields favorable outcomes for the large majority of patients, although increased LR was observed among those with non-luminal A subtypes, younger age, and increasing lymph node involvement. Risk factors for LR following BCT appear to be converging with those following mastectomy in the current era.

Citation Format: Braunstein LZ, Taghian AG, Niemierko A, Salama L, Capuco A, Wong JS, Punglia RS, Bellon JR, MacDonald SM, Harris JR. Breast cancer subtype, age and lymph node status as predictors of local recurrence following breast-conserving therapy [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-12-04.

Abstract P3-17-07: Improved long-term outcomes of breast-conserving therapy for women with ductal carcinoma in situ

Purpose: Improved mammographic and surgical techniques and pathologic evaluation, particularly greater attention to achieving negative margins, have resulted in decreased local recurrence rates for patients with ductal carcinoma in situ (DCIS). This is an updated analysis of local outcomes after breast-conserving surgery (BCS) and adjuvant radiation therapy (RT) at a single institution in the modern era.

Methods and Materials: We retrospectively reviewed the records of 245 women treated for DCIS with BCS and RT between 2001 and 2007. Competing risk analysis was used to calculate local recurrence (LR) as a first event with the development of a second non-breast malignancy, contralateral breast cancer, and death as competing first events. The median age at diagnosis was 54 (range, 32-84) and 174 (93%) women had estrogen receptor (ER) and/or progesterone receptor (PR) positive disease. Ninety-five (39%) were grade III. Specimen radiograph during surgery was obtained for 223 women (91%) and post-operative mammogram for 102 (42%). Half underwent more than one excision. The institutional goal for margins during the study period was 3 mm or greater; final margins were &gt;2 mm in 221 (90%). All received adjuvant radiation therapy to the whole breast (median whole breast dose: 4400; range, 4000 - 5220) and nearly all (99%) received a boost to the surgical cavity (median boost dose: 1600; range, 800 – 1800). Among patients with ER and/or PR+ disease, 105 (60%) received adjuvant hormonal therapy.

Results: At a median follow-up of 10.6 years, 4 patients had a LR (2 DCIS, 2 invasive ductal carcinoma) as a first event with a cumulative LR incidence of 0.0% and 1.5% at 5 and 10 years, respectively. The 5 and 10-year cumulative incidence of the competing first events is seen in the table below. Twenty women developed a contralateral breast cancer (CBC; 8 DCIS, 12 invasive carcinoma), 13 were diagnosed with a second non-breast malignancy (3 endometrial, 2 fallopian tube, 1 gallbladder, 1 leukemia and thyroid, 4 lung, 1 ovarian, and 1 uterine), and 7 died. Family history, age at diagnosis, and receipt of hormonal therapy were not significantly associated with the development of CBC on univariable analysis (all p&gt;0.05).

Incidence of local recurrence and competing eventsEvent5-year cumulative incidence10-year cumulative incidenceLocal recurrence0.0%1.5%Contralateral Breast Cancer2.5%7.9%Second non-breast malignancy2.6%4.5%Death1.2%3.5%

Conclusions: With longer follow-up, our rates of local recurrence following breast-conserving therapy for DCIS remain very low (1.5% at 10 years). The vast majority of patients had &gt;2 mm margins, specimen radiographs, and received a tumor bed boost. The majority (60%) of patients with hormone receptor positive disease received adjuvant endocrine therapy. The 10-year incidence of CBC was higher than expected. Predisposing factors for the development of CBC are worthy of investigation.

Citation Format: Warren LE, Chen Y-H, Halasz LM, Capuco A, Bellon JR, Brock JE, Punglia RS, Wong JS, Harris JR. Improved long-term outcomes of breast-conserving therapy for women with ductal carcinoma in situ [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-17-07.

Abstract PL1: Critical Decision Making in Radiation Therapy for Breast Cancer in 2015

In 2005, the EBCTCG meta-analysis demonstrated for the first time that RT after either breast-conserving surgery (BCS) or mastectomy not only reduced local-regional recurrence (LRR), but also improved long-term survival. At the time, they (erroneously) postulated that for every 4 LRR's avoid at 5 years, there was an additional survivor at 15 years. The EBCTCG subsequently adopted 'any first recurrence' as the primary endpoint for the effect of RT based on 1 – RT's established systemic effect in reducing both local and distant recurrence, 2 – that time to LRR is not strictly valid, and 3 – that the ratio between reduction in LRR and improvement in survival no longer held up. The new 'ratio' is that for every 1.5 first recurrences avoided at 10 years, there is an additional survivor at 20 years.

Over the last several decades, there has been a substantial reduction in local recurrence (LR) after BCS and RT. In series of patients treated in the 1970's, 5-year rate of LR was about 10% and in more recent series, it is about 2%. This decrease is attributable to 1 – improved mammographic evaluation, 2 – improved pathologic evaluation, and probably most importantly, 3 – the benefit seen with the addition of adjuvant systemic therapy. Also, over this time frame, risk factors for LR evolved with approximated subtype using ER, PR, HER2 status and either grade or Ki-67 now the main risk factor. 5-year LR is 6% for triple negative cancers and only about 1% for Luminal A cancers. Finally, hypofractionated breast irradiation has been established as at least equal to conventional fractionation.

Updated EBCTCG results show consistent proportional benefits for RT after either BCS or mastectomy although the absolute benefit is quite small in many subgroups. The addition of RT to BCS improves 15-year mortality by 8.5% in node-positive patients, but only 3.3% in node-negative patients.

Additionally, in the context of routine adjuvant systemic therapy, breast tangential irradiation (that treats much of the lower axilla) is sufficient to avoid regional recurrence if only 1 or 2 sentinel nodes are involved obviating the need for cALND. Also, there is evidence that internal mammary node and supraclavicular irradiation can improve 10-year disease-free survival in some patients treated with ALND.

Critical issues currently include:

1. Which patients can be spared RT after BCS? The CALGB has established hormonal therapy alone as a reasonable option in patients aged &gt; 70 years with largely low-grade, node-negative, ER+ breast cancer. Efforts are underway to identify additional ER+ patients who can be adequately managed by hormonal therapy alone. We are testing this approach in patients aged 50-75 with node-negative Luminal A cancers as determined by the Prosigna PAM-50 assay.

2. Which patients can be treated with hypofractionated RT? Available evidence is that it is nearly all patients getting breast tangents assuming adequate dose homogeneity.

3. In patients with 1 or 2 + SN's, should they receive high tangents (per Z-11) or full axillary and SC irradiation (per MA.20)? No easy answer, but one can use MD Anderson nomogram to estimate likelihood of + nSN's. If this is &lt; 25-30%, consider high tangents. If the primary is in the inner quadrant, it seems prudent to contour the IMN's for possible inclusion.

Citation Format: Harris JR. Critical Decision Making in Radiation Therapy for Breast Cancer in 2015. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr PL1.

Health care delivery for head-and-neck cancer patients in Alberta: a practice guideline

BACKGROUND

The treatment of head-and-neck cancer is complex and requires the involvement of various health care professionals with a wide range of expertise. We describe the process of developing a practice guideline with recommendations about the organization and delivery of health care services for head-and-neck cancer patients in Alberta.

METHODS

Outcomes of interest included composition of the health care team, qualification requirements for team members, cancer centre and team member volumes, infrastructure needs, and wait times. A search for existing practice guidelines and a systematic review of the literature addressing the organization and delivery of health care services for head-and-neck cancer patients were conducted. The search included the Standards and Guidelines Evidence (sage) directory of cancer guidelines and PubMed.

RESULTS

One practice guideline was identified for adaptation. Three additional practice guidelines provided supplementary evidence to inform guideline recommendations. Members of the Alberta Provincial Head and Neck Tumour Team (consisting of various health professionals from across the province) provided expert feedback on the adapted recommendations through an online and in-person review process. Selected experts in head-and-neck cancer from outside the province participated in an external online review.

SUMMARY

The recommendations outlined in this practice guideline are based on existing guidelines that have been modified to fit the Alberta context. Although specific to Alberta, the recommendations lend credence to similar published guidelines and could be considered for use by groups lacking the resources of appointed guideline panels. The recommendations are meant to be a guide rather than a fixed protocol. The implementation of this practice guideline will depend on many factors, including but not limited to availability of trained personnel, adequate funding of infrastructure, and collaboration with other associations of health care professionals in the province.

Cryptococcus gattii in the United States: clinical aspects of infection with an emerging pathogen

BACKGROUND

Cryptococcus gattii (Cg) has caused increasing infections in the US Pacific Northwest (PNW) since 2004. We describe this outbreak and compare clinical aspects of infection in the United States among patients infected with different Cg genotypes.

METHODS

Beginning in 2005, PNW state health departments conducted retrospective and prospective passive surveillance for Cg infections, including patient interviews and chart reviews; clinical isolates were genotyped at the US Centers for Disease Control and Prevention (CDC). We examined symptom frequency and underlying conditions in US patients with Cg infection and modeled factors associated with death.

RESULTS

From 1 December 2004 to July 2011, 96 Cg infections were reported to the CDC. Eighty-three were in patients in or travelers to the PNW, 78 of which were genotypes VGIIa, VGIIb, or VGIIc (outbreak strains). Eighteen patients in and outside the PNW had other molecular type Cg infections (nonoutbreak strains). Patients with outbreak strain infections were more likely than those with nonoutbreak-strain infections to have preexisting conditions (86% vs 31%, respectively; P < .0001) and respiratory symptoms (75% vs 36%, respectively; P = .03) and less likely to have central nervous system (CNS) symptoms (37% vs 90%, respectively; P = .008). Preexisting conditions were associated with increased pneumonia risk and decreased risk of meningitis and CNS symptoms. Nineteen (33%) of 57 patients died. Past-year oral steroid use increased odds of death in multivariate analysis (P = .05).

CONCLUSIONS

Clinical differences may exist between outbreak-strain (VGIIa, VGIIb, and VGIIc) and nonoutbreak-strain Cg infections in the United States. Clinicians should have a low threshold for testing for Cg, particularly among patients with recent travel to the PNW.

Abstract P1-15-07: Improved Outcomes of Breast-Conserving Surgery (BCS) and Radiation Therapy (RT) for Ductal Carcinoma In Situ (DCIS)

Background: DCIS patients treated at our center from 1976 to 1990 had an actuarial 10-year local recurrence (LR) rate of 15%. Since then, improved mammographic and pathologic evaluation and greater attention to achieving negative margins may have translated to lower risk of LR following BCS + RT for DCIS. However, the clinical implications of hormone-receptor and HER2 status in DCIS remain unclear. We sought to determine 1) if LR rates following BCS + RT have improved with this more modern approach, 2) the relation between the LR rate and HER2 status, and 3) clinical and pathologic factors associated with HER2+ tumors. Methods: We reviewed records of 246 consecutive patients who underwent BCS and adjuvant RT for DCIS at a single academic institution from 2001 to 2007. The median age at diagnosis was 54 years. One hundred and forty-one patients (57%) were postmenopausal and 226 (92%) were diagnosed after routine screening mammogram. Fifty percent of patients underwent re-excision. The median volume of excised tissue was 78 cm3 (interquartile range, 43-143 cm3) and the median number of tissue blocks with DCIS was 3 (interquartile range, 2-7). Forty tumors (16%) were grade I, 110 (45%) were grade II and 96 (39%) were grade III. Final margins were negative (&gt;2 mm) for 222 patients (90%), close (≥2 mm) for 23 (9%) and positive for 1 (0%). The median dose to the whole breast was 44 Gy (range, 40-52 Gy) and 244 (99%) received a boost to the primary site of median dose 16 Gy (range, 8-18 Gy). Routine estrogen-receptor (ER), progesterone-receptor (PR), and HER2 testing was instituted in 2003. Of the 163 patients with HER2 testing, 33 (20%) had HER2+ tumors (3+ on immunohistochemistry). Of the 186 patients with ER and/or PR testing, 174 (94%) had ER and/or PR+ tumors and of these, 104 (60%) received adjuvant hormonal therapy. Logistic regression was used to evaluate the association of clinical and pathologic factors with HER2 status. Results: With a median follow-up period of 58 months (range, 4.2-110 months), there were no LRs among the 246 patients. Seven patients (3%) developed contralateral breast cancer, of which 4 were invasive and 3 were in situ. Seven patients (3%) died of causes unrelated to breast cancer. On univariate analysis, HER2+ was significantly associated with grade III, ER-/PR-, central necrosis, comedo subtype, more extensive DCIS (based on the number of tissue blocks with DCIS), and postmenopausal status. When adjusted for ER/PR and grade, postmenopausal status remained significantly associated with HER2+ (odds ratio 3.3; 95% CI 1.2-8.7; p=0.019).

Conclusions: In an era of routine detailed mammographic and pathologic evaluation, widely negative margins and the use of a boost to the primary site in patients with DCIS, we observed no local recurrences with a median follow-up time of 58 months, even among patients with HER2+ DCIS. Factors associated with HER2+ tumors included postmenopausal status and more extensive DCIS, as well as grade III, ER-/PR-, central necrosis, and comedo subtype. Further follow-up and additional studies are required to confirm these results.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-15-07.

ROPS performance during field upset and static testing

Agriculture remains one of the most hazardous occupations in the U.S. By conservative estimates, tractor overturns alone claim 120 lives annually. A rollover protective structure (ROPS) and a seatbelt are a highly effective engineering safety control that can prevent many of these fatalities and reduce the severity of injuries associated with tractor overturn. SAE J2194 is a consensus performance standard established for agricultural ROPS. According to this standard, satisfactory ROPS performance can be demonstrated through static testing, field upset testing, or impact testing. A previous modeling study suggested that static testing may underpredict the strain induced in a ROPS during afield upset. In the current study, field upset testing and laboratory static testing results were compared. Field upset testing included six rear and six side upset tests performed according to SAE J2194 guidelines. Additionally, static testing was performed on a ROPS of the same model. The results support findings from the modeling study. Near the lowest sections of the ROPS, the plastic strain resulting from rear upset testing exceeded the plastic strain from static testing for 18 of 24 data points. Conversely, the ROPS plastic strain from side upset testing was typically less than plastic strain from laboratory static testing. However, data indicate that the side upset test may not be very repeatable. This study suggests that the longitudinal loading energy criterion for static testing might not be a conservative predictor of rear upset ROPS response.

Multicenter dizygotic twin cohort study confirms two linkage susceptibility loci for body mass index at 3q29 and 7q36 and identifies three further potential novel loci

OBJECTIVE

To identify common loci and potential genetic variants affecting body mass index (BMI, kg m(-2)) in study populations originating from Europe.

DESIGN

We combined genome-wide linkage scans of six cohorts from Australia, Denmark, Finland, the Netherlands, Sweden and the United Kingdom with an approximately 10-cM microsatellite marker map. Variance components linkage analysis was carried out with age, sex and country of origin as covariates.

SUBJECTS

The GenomEUtwin consortium consists of twin cohorts from eight countries (Australia, Denmark, the Netherlands, Finland, Italy, Norway, Sweden and the United Kingdom) with a total data collection of more than 500,000 monozygotic and dizygotic (DZ) twin pairs. Variance due to early-life events and the environment is reduced within twin pairs, which makes DZ pairs highly valuable for linkage studies of complex traits. This study totaled 4401 European-originated twin families (10,535 individuals) from six countries (Australia, Denmark, the Netherlands, Finland, Sweden and the United Kingdom).

RESULTS

We found suggestive evidence for a quantitative trait locus on 3q29 and 7q36 in the combined sample of DZ twins (multipoint logarithm of odds score (MLOD) 2.6 and 2.4, respectively). Two individual cohorts showed strong evidence independently for three additional loci: 16q23 (MLOD=3.7) and 2p24 (MLOD=3.4) in the Dutch cohort and 20q13 (MLOD=3.2) in the Finnish cohort.

CONCLUSION

Linkage analysis of the combined data in this large twin cohort study provided evidence for suggestive linkage to BMI. In addition, two cohorts independently provided significant evidence of linkage to three new loci. The results of our study suggest a smaller environmental variance between DZ twins than full siblings, with a corresponding increase in heritability for BMI as well as an increase in linkage signal in well-replicated regions. The results are consistent with the possibility of locus heterogeneity for some genomic regions, and indicate a lack of major common quantitative trait locus variants affecting BMI in European populations.

Ultrastructure of the bone marrow in HIV infection: evidence of dyshaemopoiesis and stromal cell damage

The ultrastructure of bone marrow cells was studied in nine patients infected with the human immunodeficiency virus (HIV). Two of these (cases 1 and 3) were thrombocytopenic, had never suffered from opportunistic infections and had not received any drugs prior to the time of study. A number of ultrastructural abnormalities were found in a variable proportion of the affected cell types in all nine patients. These were: (a) an increased prevalence of multivesicular bodies within several cell types and of abnormalities of the nuclear membrane in neutrophil granulocytes, (b) an increase in the size of the Golgi apparatus and in the quantity of endoplasmic reticulum in neutrophil granulocytes, (c) dysplastic features, including multiple long intranuclear clefts and large cytoplasmic vacuoles in some erythroblasts and (d) vacuolation of the plasma cells. Other abnormalities seen in a proportion of the patients were: (a) cylindrical confronting cisternae (CCC) in some of the lymphocytes, macrophages (phagocytic reticular cells), non-phagocytic reticular cells (including adventitial cells) and endothelial cells of marrow sinusoids, (b) tubuloreticular structures (TRS) in some lymphocytes, plasma cells, monocytes and endothelial cells and (c) precipitates of protein within occasional erythroblasts and marrow reticulocytes. There was also a striking and hitherto undescribed abnormality of the structure of the nucleus in intersinusoidal and perisinusoidal non-phagocytic reticular cells. This was seen in six patients, including case 3, and was characterized by the extensive detachment of masses of abnormally electron-dense heterochromatin from the nuclear membrane, the presence of a uniformly thin layer of electron-dense material at the inner surface of the areas of nuclear membrane denuded of heterochromatin masses and an abnormal electron lucency of areas containing euchromatin. The CCC and TRS were found in the six patients with the lowest number of circulating CD4-positive T cells. The precipitation of protein within erythroid cells may have been caused by the oxidant effect of dapsone or high doses of co-trimoxazole. The abnormalities in the stromal cells and in particular the nuclear changes seen in the non-phagocytic reticular cells support the possibility that one of the mechanisms underlying the cytopenia in patients infected with HIV may be a disturbance of the microenvironmental regulation of haemopoiesis.

Dual antiplatelet therapy monitoring for neurointerventional procedures using a point-of-care platelet function test: a single-center experience

BACKGROUND AND PURPOSE

Growing evidence of the relationship between poor antiplatelet response and occurrence of clinical events elicited the need of monitoring the response which has not been part of our daily practice. We present our initial experience with a new point-of-care antiplatelet-function test (VerifyNow assay) in neurointerventional procedures.

MATERIALS AND METHODS

Among the 106 consecutive patients from July 2006 to April 2007, ninety-eight met the inclusion criteria. Our preferred antiplatelet regimen was aspirin (325 mg daily) and clopidogrel (300 mg of loading dose followed by 75 mg daily) starting 5-10 days before the procedure. The test results were reported as aspirin-reaction unit (ARU) for aspirin and P2Y(12) reaction units (PRU), baseline (BASE), and percentage inhibition for the P2Y(12) assay and were summarized as mean +/- SD of the values. We analyzed the effects of several factors of poor clopidogrel response (<40% inhibition). The occurrence of thrombotic events was recorded.

RESULTS

The mean ARU of aspirin assays was 438.3 +/- 47.9 (range, 350-632), and the response was poor in 2 patients (2.1%). For clopidogrel, the mean of the BASE, PRU, and percentage inhibition was 356.8 +/- 56.3 (range, 234-495), 198.9 +/- 104.4 (range, 8-401), and 45.2 +/- 27.1% (range, 0-98), respectively. Forty-two patients (42.9%) showed poor response. Multivariate analysis showed greater body weight (81.9 Kg +/- 19.1 kg versus 69.9 +/- 15 kg) in the poor-response group. All 3 cases of intraprocedural thrombosis (3.1%) were observed only in the poor-response group.

CONCLUSION

We observed a high frequency of poor clopidogrel responses in the neurointerventional setting. Routine monitoring of the drug response would be helpful for the early identification of poor antiplatelet responders so that we may modify the regimen and/or treatment plan.

Psoriasis in Norwegian twins: contribution of genetic and environmental effects

BACKGROUND

Psoriasis is a chronic T-cell-mediated immunological skin disease with a complex pathogenesis where both genetic and environmental factors are involved.

OBJECTIVE

To study the conditional and relative risk of developing psoriasis in identical and fraternal twins whose co-twin has a positive history of the disease and to estimate the relative contribution of genetic and environmental factors on the liability for psoriasis in Norway.

METHODS

Self-reported history of psoriasis in twins from the population-based Norwegian Twin Panel (N = 8045) was studied. Absolute and relative risks of developing psoriasis conditioned on the positive history of psoriasis in a co-twin were calculated by Kaplan-Meier survival analysis and Cox regression, respectively. Structural equation modelling was used to estimate genetic and environmental variance components.

RESULTS

Altogether, 334 (4.2%) of the twins reported having psoriasis. No difference in prevalence of the disease across sexes and zygosity groups was found. Identical twins were more likely to develop psoriasis than fraternal twins if a co-twin reported having the disease. The best-fitting model showed that additive genetic effects could explain 66% of the variation in liability for psoriasis in this population, and the remaining 34% was due to non-shared environmental influences.

CONCLUSIONS

High heritability due to additive genetic effects together with considerable environmental contribution to the liability of psoriasis support the current opinion on the multifactorial aetiology of the disease. No sex-specific patterns of heritability of psoriasis were found.

Longitudinal density modulation and energy conversion in intense beams

Density modulation of charged particle beams may occur as a consequence of deliberate action, or may occur inadvertently because of imperfections in the particle source or acceleration method. In the case of intense beams, where space charge and external focusing govern the beam dynamics, density modulation may, under some circumstances, be converted to velocity modulation, with a corresponding conversion of potential energy to kinetic energy. Whether this will occur depends on the properties of the beam and the initial modulation. This paper describes the evolution of discrete and continuous density modulations on intense beams and discusses three recent experiments related to the dynamics of density-modulated electron beams.

Irritable bowel syndrome in twins: genes and environment

BACKGROUND AND AIMS

Both environmental and genetic factors may contribute to irritable bowel syndrome (IBS). Nutrition in fetal life, an early environmental factor, seems to influence the development of chronic diseases later in life, such as coronary heart disease, hypertension, and non-insulin diabetes. This population based twin study evaluated the association between intrauterine growth, measured by weight and gestational age, and IBS. Structural equation analyses were conducted to analyse genetic and environmental sources of variation in liability to IBS.

METHODS

A postal questionnaire was sent to 12 700 Norwegian twins born between 1967 and 1979. The questionnaire included a checklist of 31 illnesses and symptoms, including IBS. The influence of birth weight on developing IBS was tested in four weight groups. Disease discordant monozygotic (MZ) pairs were analysed to test the association between intrauterine growth and IBS.

RESULTS

Concordance for IBS was significantly greater (p = 0.011) in monozygotic (22.4%) than in dizygotic (9.1%) twins. The heritability of IBS was estimated to be 48.4% among females. Birth weight below 1500 g (adjusted odds ratio 2.4 (95% confidence interval 1.1, 5.3)) contributed significantly to the development of IBS, which appeared 7.7 years earlier than in higher weight groups. In the MZ group with birth weights lower than 2500 g, twins with IBS were significantly lighter than twins without disease (190.6 g; p = 0.02).

CONCLUSION

The present study demonstrates that restricted fetal growth has a significant influence on the development of IBS later in life. Weight below 1500 g influences age at onset. Genetic contribution appears to be important for IBS among females.

Genetic and environmental effects on exhaled nitric oxide and airway responsiveness in a population-based sample of twins

Elevated levels of exhaled nitric oxide (eNO) and airway hyperresponsiveness are intermediate phenotypes of asthma. Using population-based data collected from a sample of twins, the present authors estimated the relative contribution of genes, family environment and nonshared environmental influences to variations in eNO and airway responsiveness (AR). In addition, the genetic and environmental sources of covariation between these two asthma-related phenotypes were investigated. The study population comprised a random sample of 377 adult twins identified through the Norwegian Twin Registry. The main outcome variables were eNO and AR to methacholine. Genetic effects accounted for 60% of the variation in eNO. Family environment accounted for 30% of the variation in AR, while nonshared environmental influences explained the remaining variation for both measures. For both eNO and AR, there were significant regression effects for atopy and smoking. The small, but significant association between eNO and AR was primarily explained by genetic factors. Sub-analyses restricted to atopic and nonsmoking twins strengthened the observation. In conclusion, variations in exhaled nitric oxide and airway responsiveness appear to be explained by different genetic and environmental variance structures. Variation in exhaled nitric oxide is explained by genetic and nonshared environmental effects, whereas an environmental model best explains the variation in airway responsiveness. Common genetic effects explain the small but significant association between exhaled nitric oxide and airway responsiveness.

Subjective well-being: genetic and environmental contributions to stability and change

BACKGROUND

Previous cross-sectional studies have found substantial genetic influences on individual variation in subjective well-being (SWB), and evidence for sex-specific genetic effects has been reported. However, the genetic and environmental influences on stability and change in SWB over time are largely unexplored.

METHOD

Questionnaire data on SWB from a population-based sample of Norwegian twins born 1967 to 1979, initially surveyed in 1992 (T1) and re-surveyed in 1998 (T2), were analysed using structural equation modelling to explore the relative effects of genetic and environmental influences on phenotypic stability and change.

RESULTS

The phenotypic cross-time correlations for SWB were 0.51 and 0.49 for males and females respectively. The best-fitting longitudinal model specified only additive genetic and individual environmental effects with qualitative and quantitative sex-specific genetic influences. For both males and females, the additive genetic factors influencing SWB were largely stable, although some time-specific genetic contributions were indicated. Cross-time correlations for genetic effects were 0.85 and 0.78 for males and females respectively. The individual environmental influences were primarily time-specific. Additive genetic effects explained approximately 80% of the phenotypic cross-time correlation. For females, the magnitude of the additive genetic effects decreased significantly from T1 to T2, whereas for males, the estimates generally remained unchanged.

CONCLUSIONS

For both males and females, long-term stability of SWB was mainly attributable to stable additive genetic factors, whereas susceptibility to change was mostly related to individual environmental factors. However, both stable environmental contributions and emerging genetic influences were indicated.

N-Alkyl-N-arylmethylpiperidin-4-amines: Novel dual inhibitors of serotonin and norepinephrine reuptake

A series of N-alkyl-N-arylmethylpiperidin-4-amines have been prepared and are demonstrated to be inhibitors of both serotonin and norepinephrine reuptake.

The University of Maryland Electron Ring: A Platform For Study of Galactic Dynamics on a Laboratory Scale

The University of Maryland electron ring (UMER) is a novel experimental storage ring designed to investigate the dynamics of large systems of collisionless particles that nevertheless interact via collective mechanisms. Heavily diagnosed and designed to circulate a 100 mA electron beam at 10 keV for several turns, UMER allows us to follow the evolution of the beam over a large number of dynamical periods. Given the similarity of dynamics between the Coulomb forces and gravitational forces, it is possible to design beam experiments that will simulate such astrophysical events as galactic merger, for instance. The cross-comparison of beam experiments with accelerator simulation codes provides invaluable benchmarks of transient processes akin to, for example, violent relaxation in stellar systems that are otherwise impossible to obtain.

Psoriasis in Norway as observed in a population-based Norwegian twin panel

BACKGROUND

Psoriasis is a chronic T-cell-mediated immunological skin disease. The occurrence of the disease appears to differ with geography and ethnicity. There is a need for epidemiological data obtained from defined population-based studies, and the sex-specific differences observed in the natural history of the disease require more attention.

OBJECTIVES

To describe the occurrence and risk of psoriasis in Norway by age and sex.

PATIENTS/METHODS

A population-based health survey was conducted in 1998 in Norwegian twins aged 19-31 years. The present study is based upon the self-reported history of psoriasis among the 8045 questionnaire responders.

RESULTS

Altogether, 334 (4.2%) reported a positive history of psoriasis. There were no sex differences in the overall prevalence rates, but significantly higher point-prevalences emerged in females in the teenage-year intervals. A fairly linear increase in incidence rates by every 4-year age-interval peaked at a lower age in females. The mean age at onset was also significantly lower in females (14.8 years) than in males (17.3 years). The absolute risk of developing psoriasis appeared higher for females across the entire age range. However, by the age of 31 the cumulative risks were similar in females and males (0.056 and 0.053, respectively).

CONCLUSIONS

In this historical cohort of Norwegian twins, we find a high prevalence of psoriasis in congruence with previously reported data among whites in north-western Europe. We have found sex-specific characteristics in point-prevalences and incidence rates which may contribute to the understanding of the earlier age at onset of the disease in females.

Amylopectin: a major component of the residual body in Cryptosporidium parvum oocysts

Amylopectin is used for carbohydrate storage in different life-stages of a number of apicomplexan parasites. We have performed an ultrastructural analysis of amylopectin granules from the oocyst residual body and sporozoites of Cryptosporidium parvum. Amylopectin granules were studied in situ and after isolation from 'French' press disrupted parasites, by conventional transmission electron microscopy (TEM) of sectioned oocysts and various negative staining and cryoelectron microscopy techniques. Within the membrane-enclosed oocyst residuum large amylopectin granules (0.1-0.3 microm) can be found besides a characteristic large lipid body and a crystalline protein inclusion. Smaller granules were detected in sectioned sporozoites. Negative staining of isolated amylopectin granules revealed some ultrastructural features not readily visible in sectioned material. The large amylopectin granules had a smooth surface with a 'ball of string'-like inner structure. Granules isolated from sporozoites were more irregularly shaped and showed a rod-like particulate composition. With the exception of alpha-amylase, which led to some degree of damage of the surface of the particles, treatment of amylopectin granules with other glycohydrolases had little effect on the overall structure. However, granules adhered to one another. Only when the granules were boiled did the 'ball of string' structure gradually dissolve.

Gender differences in binge-eating: a population-based twin study

OBJECTIVE

To assess whether genetic and environmental effects on liability to binge-eating (BE) are of equal importance for males and females and whether the same genetic risk factors predispose to BE in the two sexes.

METHOD

Questionnaire data on 8045 same sex and opposite sex twins, aged 19-31 years, from a population-based Norwegian registry, was used to estimate the relative contribution of genetic and environmental factors to liability for BE utilizing structural equation modeling.

RESULTS

In the best-fitting model, the magnitude of genetic and environmental effects on BE was the same for males and females. Heritability was 51%. The correlation between genetic risk factors in men and women was estimated to be +0.57.

CONCLUSION

Binge-eating appears to be equally heritable in males and females. Although the majority of the genetic risk factors are shared between the sexes, there may exist gender-specific genetic effects on liability.

In vitro fibrillogenesis of the amyloid beta 1-42 peptide: cholesterol potentiation and aspirin inhibition

Understanding the formation of extracellular amyloid neurofibrillar bundles/senile plaques and their role in the development of Alzheimer's disease is of considerable interest to neuroscientists and clinicians. Major components of the extracellular neurofibrillar bundles are polymerized amyloid beta (Abeta) peptides (1-40), (1-42) and (1-43), derived in vivo from the soluble amyloid precursor protein (sAPP) by proteolytic (beta- and gamma-secretase) cleavage. The Abeta(1-42) peptide is widely considered to be of greatest significance in relation to the pathogenesis of Alzheimer's disease. A well-defined ultrastructural characteristic within Alzheimer dense plaques is the presence of helical fibrils that are believed to consist of polymerized amyloid beta, together with other associated proteins such as the serum amyloid P protein, apolipoprotein E isoform epsilon 4, alpha1-anti-chymotrypsin, catalase, glycoproteins, proteoglycans, cholesterol and other lipids. The spontaneous in vitro fibrillogenesis of chemically synthesized Abeta(1-42) peptide (rat sequence), following 20h incubation at 37 degrees C, has been assessed from uranyl acetate negatively stained specimens studied by transmission electron microscopy (TEM). Amyloid beta(1-42) peptide fibrillogenesis in the presence of cholesterol has been investigated using aqueous suspensions of microcrystalline cholesterol and cholesteryl acetate, globular particles of cholesteryl oleate, a soluble (micellar) cholesterol derivative (polyoxyethyl cholesteryl sebacate/cholesteryl PEG 600 sebacate), cholesterol-sphingomyelin liposomes and sphingomyelin liposomes. In all these cases, with the exception of cholesteryl oleate, considerable potentiation of long smooth helical fibril formation occurred, compared to 20h 37 degrees C control samples containing the Abeta(1-42) peptide alone. The binding of polyoxyethyl cholesteryl sebacate micelles to helical Abeta fibrils/filaments and the binding of fibrils to the surface of cholesterol and cholesteryl acetate microcrystals, and to a lesser extent on cholesteryl oleate globules, indicates an affinity of the Abeta peptide for cholesterol. This potentiation of Abeta(1-42) polymerization is likely to be mediated at the molecular level via hydrophobic interaction between the amino acid side chains of the peptide and the tetracyclic sterol nucleus. Addition of cupric sulphate (0.1mM) to the Abeta solution produced large disorganized fibril aggregates. Inclusion of 1mM aspirin (sodium acetylsalicylate) in the Abeta peptide alone and as an addition to Abeta peptide solution containing cholesterol, cholesteryl acetate, soluble cholesterol, sphingomyelin and sphingomyelin-cholesterol liposomes, and to 0.1mM cupric sulphate solution, completely inhibited fibrillogenesis. Instead, only non-crystalline diffuse, non-filamentous microaggregates of insoluble Abeta particles were found, free and attached to the sterol particles. The in vitro system presented here provides a way to rapidly monitor at the structural/TEM level other compounds (e.g. chelating agents, drugs, beta-sheet breaking peptides and anti-oxidants) for their effects on amyloid beta peptide fibrillogenesis (and on preformed fibril disassembly) in parallel with in vitro biochemical studies and in vivo studies using animal models of Alzheimer's disease as well as studies on man.

Back-neck pain and symptoms of anxiety and depression: a population-based twin study

BACKGROUND

Clinical and epidemiological studies have shown an association between anxiety and depression and pain in the back and neck. The nature of this relationship is not clear. This study aimed to investigate the extent to which common genetic and environmental aetiological factors contribute to the covariance between symptoms of anxiety and depression and back-neck pain.

METHODS

Measures of back-neck pain and symptoms of anxiety and depression were part of a self-report questionnaire sent in 1992 to twins born in Norway between 1967 and 1974 (3996 pairs). Structural equation modelling was applied to determine to what extent back-neck pain and symptoms of anxiety and depression share genetic and environmental liability factors.

RESULTS

The phenotypic correlation between symptoms of anxiety and depression and back-neck pain was 0.31. Individual differences in both anxiety and depression and back-neck pain were best accounted for by additive genetic and individual environmental factors. Heritability estimates were 0.53 and 0.30 respectively. For back-neck pain, however, a model specifying only shared- and individual environmental effects could not be rejected. Bivariate analyses revealed that the correlation between back-neck pain and symptoms of anxiety and depression was best explained by additive genetic and individual environmental factors. Genetic factors affecting both phenotypes accounted for 60% of the covariation. There were no significant sex differences.

CONCLUSION

The results support previous findings of a moderate association between back-neck pain and symptoms of anxiety and depression, and suggest that this association is primarily due to common genetic effects.

Physical activity affects the prevalence of reported wheeze

The present study examines whether physical activity level (hours per week) among children with and without asthma are associated with the prevalence of reported wheezing and whistling in the chest in the last 12 months. The data are based on a survey of school children, aged 7-16 years (n = 2188), in Oslo in 1994 that employed the ISAAC questionnaire. In children reporting asthma, wheezing and whistling in the chest in the last 12 months was less prevalent among inactive children (66.7%) compared to those who exercised (89.4%) (p = 0.05). The prevalence of wheeze also differed among inactive (4.4%) and active (8.8%) children not reporting asthma (p = 0.02). Positive associations between physical activity and wheezing and whistling in the chest remained present using multiple logistic regression analysis adjusting for sex, age and atopy. Children who are engaged in sports or exercise seem to report asthma symptoms differently than inactive children. These findings raise the question whether level of physical activity could affect some of the variability in reported asthma symptoms when such morbidity is measured as 'wheeze in last 12 months'.

Dynamic performance of the mechanism of an automatically deployable ROPS

The mechanism for an automatically deployable ROPS (AutoROPS) has been designed and tested. This mechanism is part of an innovative project to provide passive protection against rollover fatality to operators of new tractors used in both low-clearance and unrestricted-clearance tasks. The device is a spring-action, telescoping structure that releases on signal to pyrotechnic squibs that actuate release pins. Upper post motion begins when the release pins clear an internal piston. The structure extends until the piston impacts an elastomeric ring and latches at the top position. In lab tests the two-post structure consistently deployed in less than 0.3 s and latched securely. Static load tests of the telescoping structure and field upset tests of the fully functional AutoROPS have been successfully completed.

Static load test performance of a telescoping structure for an automatically deployable ROPS

The automatically deployable ROPS was developed as part of an innovative project to provide passive protection against overturn fatality to operators of new tractors used in both low-clearance and unrestricted-clearance tasks. The primary objective of this phase of the research was to build a telescoping structure that would prove that a ROPS can be built that will (1) reliably deploy on signal, (2) rise in a sufficiently short amount of time, (3) firmly latch in its deployed position, and (4) satisfy SAE J2194 testing requirements. The two-post structure had previously been found to meet deployment time criteria, and design analyses indicated that neither the slip-fit joint nor the latch pins would fail at test loading. Four directions of static loading were applied to the structure to satisfy SAE requirements. For the series of static loading tests, the raised structure was found to maintain a protective clearance zone after all loads were applied. The structure is overly stiff and should be redesigned to increase its ability to absorb ground-impact energy. Results of dynamic tests and field upset tests are reported in companion articles. The next phase of development is to optimize the structure so that it will plastically deform and absorb energy that would otherwise be transferred to the tractor chassis.

Marine tumor vaccine carriers: structure of the molluscan hemocyanins KLH and htH

Keyhole limpet hemocyanin (KLH) is a well-established immune stimulant and hapten carrier, and Haliotis tuberculata hemocyanin (HtH) is a related product. Biologically, KLH and HtH are blue copper proteins which serve as oxygen carriers in the blood of the keyhole limpet Megathura crenulata and the abalone H. tuberculata, respectively, two marine gastropods. Both hemocyanins occur as two distinct isoforms, termed KLH1 KLH2, HtH1, and HtH2. Each of these molecules is based on a very large polypeptide chain, the subunit (molecular mass ca 400 kDa), which is folded into a series of eight globular functional units (molecular mass ca 50 kDa each). Twenty copies of this subunit form a cylindrical quaternary structure (molecular mass ca 8 MDa). This article reviews the recent data on the biosynthesis, quaternary structure, subunit architecture, amino acid sequence, gene structure, and recombinant production of KLH and HtH.

Preventing tractor rollover fatalities: performance of the NIOSH autoROPS

Approximately 132 agricultural tractor overturn fatalities occur per year. The use of rollover protective structures (ROPS), along with seat belts, is the best known method for preventing these fatalities. One impediment to ROPS use, however, is low clearance situations, such as orchards and animal confinement buildings. To address the need for ROPS that are easily adapted to low clearance situations, the Division of Safety Research, National Institute for Occupational Safety and Health (NIOSH), developed an automatically deploying, telescoping ROPS (Auto-ROPS). The NIOSH AutoROPS consists of two subsystems. The first is a retractable ROPS that is normally latched in its lowered position for day-to-day use. The second subsystem is a sensor that monitors the operating angle of the tractor. Ifa rollover condition is detected by the sensor, the retracted ROPS will deploy and lock in the full upright position before ground contact. Static load testing and field upset tests of the NIOSH AutoROPS have been conducted in accordance with SAE standard J2194. Additionally, timed trials of the AutoROPS deployment mechanism were completed. The design of the retractable ROPS and sensor, as well as the results of the different testing phases are discussed.

Transmission electron microscopical studies on some haemolymph proteins from the marine polychaete Nereis virens

The hexagonal bilayer haemoglobin molecule from Nereis virens has been investigated in a comparative study using several different negative stain electron microscopical specimen preparations (i.e. by conventional adsorption to continuous carbon support films, by the negative staining-carbon film technique and by negative staining across the holes of holey carbon support films with air-drying and rapid freezing/cryo-negative staining). The benefits and limitations of these different approaches are indicated, with the overall conclusion that negative staining with ammonium molybdate across holes creates the best possibilities for molecular imaging, and also has the potential for the creation of two-dimensional (2D) crystals/arrays at the fluid-air interface. Of the different negative staining procedures presented, cryo-negative staining reveals the greatest details of N. virens haemoglobin. This is exemplified by the direct visualisation of the central linker-assembly within the haemoglobin molecule, a structural feature less clearly defined by the other negative staining techniques. A discoidal lipoprotein molecule (diameter 30-60nm; thickness ca 8nm) has been detected in N. virens, which represents the first documented account of an annelid haemolymph lipoprotein. The biological implications of this lipoprotein for lipid transport remain to be established. The presence of a low concentration of ferritin molecules in N. virens haemolymph is also shown, assisted by the formation of small 2D ferritin arrays in negatively stained specimens prepared across holes.

Methods for priority setting among clinical preventive services

Methods used to compare the value of clinical preventive services based on two criteria-clinically preventable burden (CPB) and cost effectiveness (CE)-are described. A companion article provides rankings of clinical preventive services and discusses its uses for decision-makers; this article focuses on the methods, challenges faced, and solutions. The authors considered all types of data essential to measuring CPB and CE for services recommended by the U.S. Preventive Services Task Force and developed methods essential to ensuring valid comparisons of different services' relative value.

Priorities among recommended clinical preventive services

BACKGROUND

Many recommended clinical preventive services are delivered at low rates. Decision-makers who wish to improve delivery rates, but face competing demands for finite resources, need information on the relative value of these services. This article describes the results of a systematic assessment of the value of clinical preventive services recommended for average-risk patients by the U.S. Preventive Services Task Force.

METHODS

The assessment of services' value for the U.S. population was based on two dimensions: burden of disease prevented by each service and cost effectiveness. Methods were developed for measuring these criteria consistently across different types of services. A companion article describes the methods in greater detail. Each service received 1 to 5 points on each of the two dimensions, for total scores ranging from 2 to 10. Priority opportunities for improving delivery rates were determined by comparing the ranking of services with what is known of current delivery rates nationally.

RESULTS

The highest ranked services (scores of 7+) with the lowest delivery rates (< or =50% nationally) are providing tobacco cessation counseling to adults, screening older adults for undetected vision impairments, offering adolescents an anti-tobacco message or advice to quit, counseling adolescents on alcohol and drug abstinence, screening adults for colorectal cancer, screening young women for chlamydial infection, screening adults for problem drinking, and vaccinating older adults against pneumococcal disease.

CONCLUSIONS

Decision-makers can use the results to set their own priorities for increasing delivery of clinical preventive services. The methods provide a basis for future priority-setting efforts.

Endogenous sulphur-containing amino acids: potent agonists at presynaptic metabotropic glutamate autoreceptors in the rat central nervous system

We have recently demonstrated that presynaptically located metabotropic glutamate (mGlu) autoreceptors regulate synaptic glutamate release both in vitro and in vivo. We now report a positive modulatory action of the sulphur-containing amino acids (SCAAs), L-cysteic acid (CA) and L-cysteine sulphinic acid (CSA), at presynaptic group I mGlu receptors, specifically of the mGlu5 subtype, acting to enhance synaptic glutamate release from the rat forebrain in vitro. Neuronal glutamate release was monitored using electrically-evoked efflux of preloaded [(3)H]-D-aspartate from rat forebrain hemisections. Both CA (3 - 100 muM) and CSA (1 - 100 microM), in addition to the selective group I mGlu receptor agonist, (S)-3,5-dihydroxyphenylglycine ((S)-DHPG), concentration-dependently enhanced electrically-stimulated efflux of [(3)H]-D-aspartate from the rat forebrain slices. Basal efflux of label remained unchanged. The inhibitory activity of the broad spectrum mGlu receptor antagonist, (+/-)-alpha-methyl-4-carboxyphenylglycine ((+/-)-MCPG; 200 microM), coupled with the inactivity of the selective mGlu1 receptor antagonists, (R,S)-1-aminoindan-1,5-dicarboxylic acid ((R,S)-AIDA; 100 - 500 microM) and the more potent (+)-2-methyl-4-carboxyphenylglycine (LY367385; 10 microM) against these responses, indicates an action of the SCAAs at the mGlu5 receptor subtype. This proposal is supported by the potent inhibition of these responses by the selective, non-competitive mGlu5 receptor antagonist, 2-methyl-6-(phenylethynyl)pyridine (MPEP; 10 microM). The observed enhancement of the responses to high concentrations of CA by the selective mGlu5 receptor desensitization inhibitor, cyclothiazide (CYZ; 10 microM), is also consistent with this concept. Administration of the agonists in the presence of bovine serum albumin (BSA; 5 - 15 mg ml(-1)) markedly attenuated the positive modulatory responses observed, strongly supporting a role for arachidonic acid in the expression of these mGlu5 receptor-mediated responses. The regulatory actions of SCAAs on synaptic glutamate release demonstrated in the present study may provide a physiological function for these putative neurotransmitter amino acids in the mammalian brain. These central actions of the SCAAs may have wide-ranging implications for a range of neurological and neuropsychiatric disease states and their treatment.

Comparison of the decameric structure of peroxiredoxin-II by transmission electron microscopy and X-ray crystallography

The decameric human erythrocyte protein torin is identical to the thiol-specific antioxidant protein-II (TSA-II), also termed peroxiredoxin-II (Prx-II). Single particle analysis from electron micrographs of Prx-II molecules homogeneously orientated across holes in the presence of a thin film of ammonium molybdate and trehalose has facilitated the production of a >/=20 A 3-D reconstruction by angular reconstitution that emphasises the D5 symmetry of the ring-like decamer. The X-ray structure for Prx-II was fitted into the transmission electron microscopic reconstruction by molecular replacement. The surface-rendered transmission electron microscopy (TEM) reconstruction correlates well with the solvent-excluded surface of the X-ray structure of the Prx-II molecule. This provides confirmation that transmission electron microscopy of negatively stained specimens, despite limited resolution, has the potential to reveal a valid representation of surface features of protein molecules. 2-D crystallisation of the Prx-II protein on mica as part of a TEM study resulted in the formation of a p2 crystal form with parallel linear arrays of stacked rings. This latter 2-D form correlates well with that observed from the 2.7 A X-ray structure of Prx-II solved from a new orthorhombic 3-D crystal form.

Performance measures: are we measuring what matters?

BACKGROUND

The ultimate intent of healthcare performance measures is to improve health status by stimulating improvements to healthcare quality. This report evaluates how well current performance measurement sets address the leading causes of illness and death in the United States, using the Health Plan Employer Data and Information Set (HEDIS) as an example.

METHODS

We assessed whether HEDIS measures exist for the leading causes of illness and death according to five commonly used indices: physiologic cause of death, underlying cause of death, disability-adjusted life years, healthcare expenditures, and missed work days.

RESULTS

Fewer than one half of the leading causes of morbidity and mortality are addressed by current measures.

CONCLUSIONS

The opportunities for using accurate and meaningful measurement for disease prevention and health promotion are substantial, yet this potential remains only partly realized and depends on further expansion of performance measurement efforts.