Systematic literature review and meta-analysis on use of Thrombopoietic agents for chemotherapy-induced thrombocytopenia

Background

Currently, there are no approved options to prevent or treat chemotherapy-induced thrombocytopenia (CIT). We performed a systematic literature review and meta-analysis on use of thrombopoietic agents for CIT.

Patients and methods

We searched Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, PubMed, EMBASE, ClinicalTrials.gov, and health technology assessments from January 1995 to March 2021 for studies evaluating thrombopoietic agents for CIT, including recombinant human thrombopoietin (rhTPO), megakaryocyte growth and development factor (MGDF), romiplostim, and eltrombopag. Random effects meta-analyses were conducted for efficacy and safety endpoints.

Results

We screened 1503 titles/abstracts, assessed 138 articles, and abstracted data from 39 publications (14 recombinant human thrombopoietin, 7 megakaryocyte growth and development factor, 9 romiplostim, 8 eltrombopag, and 1 romiplostim/eltrombopag). Random effects meta-analyses of data from multiple studies comparing thrombopoietic agents versus control (comparator, placebo, or no treatment) showed that thrombopoietic agents did not significantly improve chemotherapy dose delays and/or reductions (21.1% vs 40.4%, P = 0.364), grade 3/4 thrombocytopenia (39.3% vs 34.8%; P = 0.789), platelet transfusions (16.7% vs 31.7%, P = 0.111), grade ≥ 2 bleeding (6.7% vs 16.5%; P = 0.250), or thrombosis (7.6% vs 12.5%; P = 0.131). However, among individual studies comparing thrombopoietic agents with placebo or no treatment, thrombopoietic agents positively improved outcomes in some studies, including significantly increasing mean peak platelet counts (186 x 10⁹/L with rhTPO vs 122 x 10⁹/L with no treatment; P < 0.05) in one study and significantly increasing platelet count at nadir (56 x 10⁹/L with rhTPO vs 28 x 10⁹/L with not treatment; P < 0.05) in another study. Safety findings included thrombosis (n = 23 studies) and bleeding (n = 11), with no evidence of increased thrombosis risk with thrombopoietic agents.

Conclusion

Our analyses generate the hypothesis that thrombopoietic agents may benefit patients with CIT. Further studies with well-characterized bleeding and platelet thresholds are warranted to explore the possible benefits of thrombopoietic agents for CIT.

Validation of Self-Reported Cancer Diagnosis by Cognitive Status in the Health and Retirement Study

Exploring the relationship between cognition and cancer is increasingly important as the number of older adults in the US grows. The Health and Retirement Study (HRS) has longitudinal data on cognitive status and self-reported cancer diagnoses, but these self-reports have not been validated. Using HRS linked to Medicare Fee for Service (FFS) claims (1998-2016), we evaluated the validity of self-reported cancer diagnoses (excluding non-melanoma skin) against Medicare claims by respondent cognitive status. We included 8,280 Medicare-eligible HRS participants aged ≥67 with at least 90% FFS coverage. Cognitive status was ascertained from the HRS interview following the date of cancer diagnosis (or reference claim date) using the Langa-Weir method and was classified as normal, cognitive impairment no dementia (CIND), or dementia. We calculated the sensitivity, specificity, and Cohen's kappa for first incident malignant cancer diagnosis by cognitive status group. The majority (76.4%) of participants scored as cognitively normal, 9.6% had CIND, 14.0% had dementia and, overall, 1,478 had an incident cancer diagnosis. Among participants with normal cognition, sensitivity of self-reported cancer diagnosis was 70.2% and specificity was 99.8% (kappa=0.79). Among participants with CIND, sensitivity was 56.7% and specificity was 99.8% (kappa=0.66). Among participants with dementia, sensitivity was 53.0% and specificity was 99.6% (kappa=0.64). Results indicate poor validity of self-reported cancer diagnoses for older adults with CIND or dementia. These findings suggest researchers interested in cancer and cognition should use the HRS-Medicare linkage to ascertain cancer diagnosis from claims, and they highlight the importance of cognitive status in research among older adults.

The relationship between ultrasound microcalcifications and psammoma bodies in thyroid tumours: a single-institution retrospective study

AIM

To investigate the diagnostic accuracy of ultrasound microcalcifications for the detection of malignancy in thyroid nodules and determine the validity of the concept that ultrasound microcalcification reflects the presence of psammoma body calcification in thyroid nodules.

MATERIALS AND METHODS

The laboratory information system at University Hospital Galway, a tertiary referral hospital, was used to compile a list of patients who underwent thyroid lobectomy or complete thyroidectomy over a continuous 12-month period with both preoperative ultrasound and postoperative histology available (n=106) from January to December 2019. The haematoxylin and eosin-stained histology slides of each case were sourced and reviewed under light microscopy by a histopathologist to determine the presence of psammoma body calcification within both benign and malignant thyroid nodules. Two radiologists reviewed preoperative thyroid ultrasound images of each case independently and blindly, and reported on the presence of ultrasonographic microcalcification.

RESULTS

There was a strong and significant relationship between the presence of preoperative ultrasound microcalcification and thyroid malignancy (p<0.001). Ultrasound microcalcification had a high specificity (93%) and positive predictive value (75%) for thyroid malignancy, with a diagnostic accuracy of 76%. Negative predictive value was high at 76.7%, while sensitivity was low at 42.8%. There was a strong and significant association between the presence of preoperative ultrasound microcalcification in thyroid nodules and the presence of pathological psammoma bodies on histology (p<0.001).

DISCUSSION

Ultrasound microcalcification has a strong and significant association with malignancy in thyroid nodules. This study supported the theory that ultrasound microcalcification occurs secondary to the presence of psammoma bodies within thyroid nodules.

Association between utilization patterns and racial disparities in hospice enrollment among women dying of ovarian cancer

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Background: Goals of care conversations are associated with less aggressive end of life care and may be most effective in an outpatient setting. Yet, the relationship between initial utilization of care and subsequent hospice enrollment is unknown. We evaluated whether inpatient, outpatient and emergency department (ED) evaluation and management (E/M) visits differed by patient race/ethnicity, and whether less outpatient management was associated with failure to enroll in hospice in a sample of women dying of ovarian cancer. Methods: Women diagnosed with first and only ovarian cancer who died between 2000 and 2016 and had ≥ one inpatient and outpatient ovarian cancer E/M encounter between diagnosis and the last two months of life in SEER-Medicare were included (N = 8,806). Women whose proportion of outpatient E/M encounters fell below the median were classified as having low outpatient management (vs. high). Multivariable-adjusted logistic regression was used to estimate the association of: (1) race/ethnicity with outpatient management, and (2) outpatient management with hospice enrollment, stratified by race/ethnicity. Models were adjusted for stage at diagnosis, histology, survival time, age, Charlson score, geographic region, and year. Results: In this sample, 29.2% of ovarian cancer E/M took place in an inpatient setting, 66.4% outpatient, and 4.4% in the ED. Non-Hispanic Black women had 53.9% of their E/M occur in an outpatient setting, compared to 67.6% in non-Hispanic White women, 60.7% in Hispanic women, and 64.2% in women of other races (p <.001). Black women had 78% greater odds of low outpatient management when compared to non-Hispanic White women (adjusted OR 1.78, 95%CI: 1.46-2.18). Women with low (vs. high) outpatient management had 33% greater odds of not enrolling in hospice (adjusted OR 1.33, 95%CI: 1.20-1.48). The association of low outpatient management with not enrolling in hospice was most pronounced among Black women (Black adjusted OR: 1.54, 95%CI: 1.02-2.32 vs. Non-Hispanic White adjusted OR: 1.32, 95%CI: 1.18-1.48). Conclusions: Although most ovarian cancer care takes place in an outpatient setting, Black women have the lowest proportion of outpatient care, and low outpatient management was associated with not enrolling in hospice. When deploying interventions to improve goals of care conversations for women with ovarian cancer, racial/ethnic disparities in care settings must be considered.

Validation of self-reported incident cancer diagnoses in the U.S. Health and Retirement Study: A tool for population-based cancer and aging research

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Background: Population aging and improving cancer survival rates are resulting in a growing population of older cancer survivors in the United States (US). As a result, there is an increasing need for longitudinal, population-representative data for interdisciplinary cancer research among older adults. The US Health Retirement Study (HRS) is an ongoing population-representative cohort of US adults over age 50 that contains rich interview and biomarker data on health during aging. Interviews have collected self-reported cancer diagnoses since 1998, but these self-reports have not been validated. We compared first incident cancer diagnoses self-reported in HRS interviews against diagnostic claims from linked Medicare records. Methods: We examined the validity of first incident cancer diagnoses self-reported in biennial HRS interviews from 2000 through 2016 against ICD-9 and ICD-10 diagnostic claim records among 8,242 HRS participants aged ≥65 with 90% continuous enrollment in fee-for-service Medicare, using the claim records as the gold standard. We calculated the sensitivity, specificity, and k for first incident cancer diagnoses (all cancers combined, excluding non-melanoma skin cancer, and each of bladder, breast, colorectal/anal, uterine, kidney/renal, lung/bronchus, and prostate cancers) cumulatively over the follow-up, and at each biennial study interview. Results: Self-reports of first incident cancer diagnosis (agnostic of site) between 2000 and 2016 had 73.2% sensitivity and 96.2% specificity against Medicare claims (k = 0.73). For site-specific self-reports, sensitivities ranged from 44.7% (kidney) to 75.0% (breast), and specificities ranged from 99.2% (prostate) to 99.9% (bladder, uterine, and kidney). Results were similar in sensitivity analyses restricting to individuals with 100% continuous fee-for-service Medicare enrollment and when restricting to individuals with at least 24 months of Medicare enrollment. Conclusions: Self-reported cancer diagnoses in the HRS have reasonable validity for population-based research on cancer and aging across cancer types. Apart from breast cancer, cancer site specific analyses will greatly benefit from the improved validity of self-report with Medicare claim linkage.

Racial segregation and cognitive function among older adults in the United States: Findings from the REasons for Geographic and Racial Differences in Stroke (REGARDS) study

OBJECTIVES

Residential segregation is one of the fundamental features of health disparities in the United States. Yet little research has examined how living in segregated metropolitan areas is related to cognitive function and cognitive decline with age. We examined the association between segregation at the Metropolitan Statistical Area (MSA) level and trajectories of age-related cognitive function.

METHOD

Using data from Black and White older adults in the REasons for Geographic and Racial Differences in Stroke (REGARDS) study (n=18,913), we employed linear growth curve models to examine how living in racially segregated MSAs at baseline, measured by the degree of Non-Hispanic Black [NHB] isolation and NHB dissimilarity, was associated with trajectories of age-related cognitive function and how the associations varied by race and education.

RESULTS

Living in MSAs with greater levels of isolation was associated with lower cognitive function (b=-0.093, p<0.05) but was not associated with rates of change in cognitive decline with age. No effects of living in isolated MSAs were found for those with at least a high school education, but older adults with less than a high school education had lower cognitive function in MSAs with greater isolation (b=-0.274, p<0.05). The degree of dissimilarity was not associated with cognitive function. The association between segregation and cognitive function did not vary by race.

DISCUSSION

Metropolitan segregation was associated with lower cognitive function among older adults, especially for those with lower education living in racially isolated MSAs. This suggests complex associations between individual socioeconomic status, place, and cognitive health.

Increased risk of thrombotic events in cold agglutinin disease: A 10-year retrospective analysis

BACKGROUND

Cold agglutinin disease (CAD) is a rare autoimmune hemolytic anemia mediated by IgM autoantibodies that trigger hemolysis via classical complement pathway. Increased incidence of thrombotic events (TEs) has been reported in patients with other forms of hemolysis. The incidence of TEs in patients with CAD is unknown.

OBJECTIVE

Evaluate TE risk in patients with CAD.

PATIENTS/METHODS

This is a matched cohort comparison study evaluating the risk of TEs in patients with CAD and without CAD over a 10-year period. A total of 608 patients with CAD were identified in the Optum Claims-Clinical data set by reviewing clinical notes for CAD terms and matched with up to 10 patients without CAD (N = 5873). TEs were defined as the first medical claim for a TE using International Classification of Diseases, Ninth and Tenth Revision codes. Cox regression models were used to estimate time to first TE. Sensitivity analyses were conducted to estimate TE risk among patients with primary CAD.

RESULTS

At least 1 TE occurred in 29.6% of patients with CAD and 17.6% of patients without CAD. The proportion of patients experiencing venous, arterial, and cerebral TEs were each higher among CAD patients. The overall risk of having TEs was higher in patients with CAD (adjusted hazard ratio [aHR], 1.94; 95% confidence interval [CI], 1.64-2.30). Patients with presumed primary CAD also demonstrated an increased risk of TEs (aHR, 1.80; 95% CI, 1.46-2.22). Patients with CAD with the fewest comorbidities had 2.44-fold higher risk of having a TE (95% CI, 1.70-3.52).

CONCLUSIONS

Patients with CAD have an increased risk of TEs when compared with a matched non-CAD population.

RACIAL RESIDENTIAL SEGREGATION AND COGNITIVE DECLINE AMONG OLDER ADULTS

Racial residential segregation may be a fundamental cause of health disparities in the U.S., and few studies employ objective measures of segregation to estimate its impacts on cognitive decline. Using data from 21,446 REGARDS participants in urban areas, we employed race-stratified growth curve models to examine how city racial segregation was associated with trajectories of cognitive decline over time. Controlling for demographics and health conditions/behaviors, higher segregation for blacks was marginally associated with lower cognitive function at baseline (b=-0.159, p&lt;.10) while higher segregation for whites was associated with better cognitive function (b=0.158, p&lt;.01). For both blacks and whites, there were no significant associations between segregation and rate of cognitive decline but neighborhood poverty was adversely related to cognitive function (b=-0.171, p&lt;.01 for blacks, b=-0.289, p&lt;.001 for whites). Further research into mechanisms that contributes to heterogeneity in associations between racial segregation and cognitive function is needed to develop effective prevention interventions.

The preferences of young adults with Type 1 diabetes at clinics using a discrete choice experiment approach: the D1 Now Study

AIM

Attending routine outpatient clinic appointments is a central self-management behaviour of individuals living with Type 1 diabetes. A large number of young adults with Type 1 diabetes disengage from diabetes services, which may contribute to poor psychosocial and diabetes outcomes. The aim of this study is to elicit preferences from young adults with Type 1 diabetes regarding clinic-related services to inform service delivery.

METHODS

A discrete choice experiment was developed to understand the preferences of young adults with Type 1 diabetes for clinic-related services.

RESULTS

Young adults recruited from young adult Type 1 diabetes clinics in 2016 completed the experiment (n = 105). Young adults with Type 1 diabetes showed a preference for shorter waiting times, seeing a nurse and a consultant, relative to a nurse alone, and a flexible booking system compared with fixed appointment times. Results suggest no preference for a nurse and a doctor, relative to a nurse alone, or other optional services (e.g. seeing dietitians or psychologists), type of HbA_1c test and digital blood glucose diaries over paper-based diaries.

CONCLUSION

This study highlights aspects of routine clinic appointments that are valued by young adults living with Type 1 diabetes, namely shorter waiting times at clinic, the option to see both a nurse and consultant at each visit and a flexible clinic appointment booking system. These findings suggest young adults with Type 1 diabetes value convenience and should help services to restructure their clinics to be more responsive to the needs of young adults.

Abstract C24: Determinants of delays in care-seeking for ovarian cancer symptoms in African American women

Introduction: Ovarian cancer is the most deadly gynecologic cancer, and the mortality burden is disproportionately higher among African American women. Women diagnosed with stage IV disease have less than a 30% 5-year survival rate, compared to 90% 5-year survival in stage I disease, which highlights the importance of early diagnosis. Lack of financial means and limited access to care may contribute to delays in symptomatic women seeking treatment, with consequent later stage at diagnosis. However, several studies, performed in samples predominantly comprised of White women, suggest insurance and income do not sufficiently reflect access to care. Here, we examine whether delay in care-seeking (captured through duration of symptoms prior to diagnosis) among African American women is more strongly influenced by socioeconomic status, access to care, or social access barriers (discrimination and trust in physicians).

Methods: This analysis includes data from 550 African American women with ovarian cancer enrolled in the African American Cancer Epidemiology Study (AACES). AACES is a case-control study spanning 11 geographic regions in the United States: North Carolina, South Carolina, Georgia, Alabama, Tennessee, Louisiana, Texas, New Jersey, Ohio, Chicago, and Detroit. Included in the phone-administered AACES survey were questions about symptoms associated with ovarian cancer such as abdominal lumps, changes in bowel habits, and abnormal vaginal bleeding, in the year prior to ovarian cancer diagnosis. If a woman indicated she had a symptom, duration of the symptom was recorded in months. Logistic regression was used to estimate the odds ratios between predictors of accessing care and the outcome of treatment delay. The outcome was defined as having any of the 10 symptoms for at least eight months prior to diagnosis (i.e., those exceeding the seven-month mean symptom duration in this population). Models were adjusted for region, age at diagnosis, histotype, first-degree family history of breast or ovarian cancer, marital status, body mass index, Charlson comorbidity score, pelvic-inflammatory disease history, education, and income. Access to care variables included regular source of health care, insurance, regular physician relationship, and experiencing a barrier to accessing health care. Perceived discrimination was evaluated using the mean response score for questions from Williams' Everyday Discrimination Scale. Trust in physicians was modeled using the mean response score from the Anderson Dedrick Trust in Physicians Scale.

Results: 41% (n=227) of women reported having at least one symptom for eight months prior to diagnosis. After adjustment for confounders, trust in physicians was inversely associated with longer duration of symptoms. A one-unit increase in the mean trust score was associated with 0.73 times the odds of women reporting undiagnosed symptoms in the previous 8 months (OR 0.73 CI 0.55-0.96). Conversely, a one-unit increase in frequency of mean everyday discrimination score was associated with 1.56 times the odds of 8 months of undiagnosed symptoms (OR 1.56 CI 1.14-2.15), after adjustment for confounders. Access to care measures and socioeconomic variables were not associated with longer symptom length in this study population.

Conclusions: Various studies have considered access to care mainly in terms of availability of health insurance. Our results suggest perceived discrimination and lack of trust in physicians are important barriers to African American women seeking treatment for their ovarian cancer symptoms, even after controlling for socioeconomic status, insurance, and source of care.

Citation Format: Megan Mullins, Michele L. Cote, Sarah Abbott, Anthony J. Alberg, Elisa V. Bandera, Jill Barnholtz-Sloan, Melissa Bondy, Fabian Camacho, Ellen Funkhouser, Patricia G. Moorman, Lauren C. Peres, Ann G. Schwartz, Paul D. Terry, Frances Wang, Joellen M. Schildkraut, Edward S. Peters. Determinants of delays in care-seeking for ovarian cancer symptoms in African American women [abstract]. In: Proceedings of the Tenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2017 Sep 25-28; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2018;27(7 Suppl):Abstract nr C24.

Strength in Numbers: an international consensus conference to develop a novel approach to care delivery for young adults with type 1 diabetes, the D1 Now Study

PLAIN ENGLISH SUMMARY

Many young adults with type 1 diabetes struggle with the day-to-day management of their condition. They often find it difficult to find the time to attend their clinic appointments and to meet with their diabetes healthcare team. Young adults living with type 1 diabetes are not routinely involved in research that may help improve health services other than being invited to take part in studies as research participants. A 3-day international conference was held in Galway in June 2016 called "Strength In Numbers: Teaming up to improve the health of young adults with type 1 diabetes". It aimed to bring together people from a broad variety of backgrounds with an interest in young adults with type 1 diabetes. Young people with type 1 diabetes came together with healthcare professionals, researchers, software developers and policy makers to come up with and agree on a new approach for engaging young adults with type 1 diabetes with their health services and to improve how they manage their diabetes.The people involved in the conference aimed to reach agreement (consensus) on a fixed set of outcome measures called a core outcome set (COS) that the group would recommend future studies involving young adults with type 1 diabetes to use, to suggest a new approach (intervention) for providing health services to young adults with type 1 diabetes, and to come up with health technology ideas that could help deliver the new intervention. Over the 3 days, this diverse international group of people that included young adults living with type 1 diabetes, agreed on a COS, 3 key parts of a new intervention and 1 possible health technology idea that could help with how the overall intervention could be delivered.Involving young adults living with type 1 diabetes in a 3-day conference along with other key groups is an effective method for coming up with a new approach to improve health services for young adults with type 1 diabetes and better support their self-management.

ABSTRACT

Background A 3-day international consensus meeting was hosted by the D1 Now study team in Galway on June 22-24, 2016 called "Strength In Numbers: Teaming up to improve the health of young adults with type 1 diabetes". The aim of the meeting was to bring together young adults with type 1 diabetes, healthcare providers, policy makers and researchers to reach a consensus on strategies to improve engagement, self-management and ultimately outcomes for young adults living with type 1 diabetes. Methods This diverse stakeholder group participated in the meeting to reach consensus on (i) a core outcome set (COS) to be used in future intervention studies involving young adults with type 1 diabetes, (ii) new strategies for delivering health services to young adults and (iii) potential digital health solutions that could be incorporated into a future intervention. Results A COS of 8 outcomes and 3 key intervention components that aim to improve engagement between young adults with type 1 diabetes and service providers were identified. A digital health solution that could potentially compliment the intervention components was proposed. Conclusion The outputs from the 3-day consensus conference, that held patient and public involvement at its core, will help the research team further develop and test the D1 Now intervention for young adults with type 1 diabetes in a pilot and feasibility study and ultimately in a definitive trial. The conference represents a good example of knowledge exchange among different stakeholders for health research and service improvement.

Explaining Disparities in Ovarian Cancer Incidence Rates between Women of African and European Ancestry: The Role of Genetic Factors

Non-Hispanic White (NHW) women are at higher risk of ovarian cancer than African-American (AA) women. Approximately 30% of the difference in age-adjusted invasive epithelial ovarian cancer incidence rates (AAIR) between the two groups can be explained by differing oophorectomy rates and the prevalence of non-genetic risk and protective factors. Our purpose was to determine how much of the remaining difference in AAIRs could be explained by varying allele frequencies between NHWs and AAs for 18 genome-wide significant common susceptibility variants for ovarian cancer. Using data on 13,385 cases and 24,875 controls from the Ovarian Cancer Association Consortium, a genetic risk score (GRS) was created from 18 single nucleotide polymorphisms (SNPs) associated with ovarian cancer risk following the Collaborative Oncological Gene-environment Study (COGS) effort. Relative risks for each GRS quintile were estimated using conditional logistic regression, adjusting for genetic ancestry and conditioning on study site, age, and race. The population attributable risk percent (PAR) for GRS above the lowest quintile was calculated using the Bruzzi method. Previously reported oophorectomy and non-genetic risk factor (talc, oral contraceptive use, family history of ovarian cancer, endometriosis, parity and tubal ligation) adjusted incidence rates for ovarian cancer in NHWs and AA's were 7.2 and 5.8 per 100,000 respectively. These incidence rates were further adjusted for the contribution of the GRS from this analysis. The subsequent genetic PAR adjusted rate was 5.1 per 100,000 for the European ancestry group and 4.9 for the African ancestry group, after taking into account the different oophorectomy rates and prevalence of non-genetic risk factors. These incidence rates show the unexplained difference in incidence rates between NHWs and AAs is only 3.9%. Future efforts should focus on incorporating novel non-genetic and genetic factors into this analysis to determine whether essentially all of the difference in incidence between these groups can be explained.

Cesarean delivery is not associated with decreased at-birth fracture rates in osteogenesis imperfecta

Purpose

Osteogenesis imperfecta (OI) predisposes to recurrent fractures. The moderate-to-severe forms of OI present with antenatal fractures and the mode of delivery that would be safest for the fetus is not known.

Methods

We conducted systematic analyses on the largest cohort of individuals (n=540) with OI enrolled to-date in the OI Linked Clinical Research Centers. Self-reported at-birth fracture rates were compared in individuals with OI types I, III, and IV. Multivariate analyses utilizing backward-elimination logistic regression model building were performed to assess the effect of multiple covariates including method of delivery on fracture-related outcomes.

Results

When accounting for other covariates, at-birth fracture rates did not differ based on whether delivery was by vaginal route or by cesarean section (CS). Increased birth weight conferred higher risk for fractures irrespective of the delivery method. In utero fracture, maternal history of OI, and breech presentation were strong predictors for choosing CS for delivery.

Conclusion

Our study, the largest to analyze the effect of various factors on at-birth fracture rates in OI shows that delivery by CS is not associated with decreased fracture rate. With the limitation that the fracture data were self-reported in this cohort, these results suggest that CS should be performed only for other maternal or fetal indications, but not for the sole purpose of fracture prevention in OI.

Human adipose microRNA-221 is upregulated in obesity and affects fat metabolism downstream of leptin and TNF-α

AIMS/HYPOTHESIS

MicroRNAs (miRNAs) are short endogenous RNAs that regulate multiple biological processes including adipogenesis and fat metabolism. We sought to identify miRNAs that correlate with BMI and to elucidate their upstream regulation and downstream targets.

METHODS

Microarray-based expression profiling of 233 miRNAs was performed on subcutaneous abdominal adipose tissue biopsies from 29 non-diabetic Pima Indian participants. Correlation of the expression levels of eight miRNAs with BMI was assessed by quantitative reverse transcription (QRT) PCR in adipose samples from 80 non-diabetic Pima Indians with a BMI of 21.6-54.0 kg/m(2). The upstream regulation of one of these miRNAs, miR-221, was tested by treating cultured human pre-adipocytes with leptin, TNF-α and insulin. Predicted targets of miR-221 were validated using QRT-PCR, immunoblots and luciferase assays. The downstream effects of miR-221 overexpression were assayed by proteomic analysis.

RESULTS

Expression levels of miR-221 were positively correlated with BMI (particularly in women) and fasting insulin concentrations, while the levels of miR-193a-3p and miR-193b-5p were negatively correlated with BMI; other miRNAs did not show significant associations in the 80 samples. miR-221 was downregulated by leptin and TNF-α treatment in cultured human pre-adipocytes. Conversely, miR-221 overexpression upregulated several proteins involved in fat metabolism, mimicking peroxisome proliferator-activated receptor (PPAR) activation. Furthermore, miR-221 directly downregulated the adiponectin receptor 1 (ADIPOR1) and the transcription factor v-ets erythroblastosis virus E26 oncogene homolog 1 (ETS1). Adiponectin signalling is known to promote insulin sensitivity, and ETS1 is crucial for angiogenesis.

CONCLUSIONS/INTERPRETATION

Our data suggest that miR-221 may contribute to the development of the insulin resistance that typically accompanies obesity, by affecting PPAR signalling pathways and by directly downregulating ADIPOR1 and ETS1.

Ilizarov wire tensioning and holding methods: a biomechanical study

AIM

To investigate and compare two specific methods of Ilizarov wire tensioning and hold.

METHOD

This study utilised the vertical Hounsfield test machine H25KS, a stress/strain device with a load-cell linked to a computer program. Firstly, the department's present mechanical tensioners were assessed. Secondly, the method of twisting the three designs of wire holding bolts to achieve wire tension, as described by Ilizarov, was assessed. These bolts are described as "cannulated", "slotted" and "Russian" (which are hexagonal headed with a slot down one side).

RESULTS

The mechanical tensioners were found to be accurate, if inefficient, with a maximum producible tension of 1330N. The most effective bolts for creation of tension were the Russian, which produced mean wire tensions of 785N at 45 degrees; 1200N at 90 degrees; 1695N at 135 degrees. The cannulated and slotted bolts regularly broke the wires at 90 degrees twist.

CONCLUSION

The findings demonstrated two effective methods. The present tensioners were found to be inefficient when compared to the simple twisting of the wire holding bolts, which created equivalent tensions with ease and are capable of producing greater wire tensions. The Russian bolts are recommended for use when wire tension is created by bolt twisting.

Sequence variation in the gene encoding the 10-kDa prolamin in Oryza (Poaceae). I. Phylogenetic Implications

Oryza L. (Poaceae) contains approximately 20 wild and two domesticated species and nine genomes. Major disagreements exist on its systematics and genome evolution. Sequence polymorphism in the gene that encodes the 10-kDa prolamin polypeptide (a seed storage protein) was used to determine phylogenetic relationships and evaluate current systematics for 19 Oryza species. This gene in Oryza is approximately 402-bp long, and includes a 72-bp signal peptide region. A strict consensus tree shows Oryza brachyantha (FF) as the most basal species, followed by a polytomy of three clades that can be delineated based on genome composition: (1) the GG clade: Oryza granulata and Oryza meyeriana, (2) the EE clade: Oryza australiensis, and (3) the ABCD clade: the remaining Oryza species. Two subclades within the ABCD clade emerge, one containing species with the AA genome, the other with components of the BC and D genomes. Members of the AA subclade form a polytomy and were delineated by a single 3-base deletion. The African species Oryza punctata (BB) and the South American-endemic CCDD genome species form a strong lineage, pointing to a close genetic affinity of O. punctata to the missing DD genome donor. The strong association between the CC and BBCC species implies convergence at the gene level. The study supports the following sectional units of Oryza: Section Oryza (Series sativae and officinaliae), Section australiensis, Section Granulata, Section Brachyantha.

Cooperative action of ADMP- and BMP-mediated pathways in regulating cell fates in the zebrafish gastrula

It was shown in Xenopus and chick that Spemann's organizer activity is regulated through the negative action of Anti-Dorsalizing Morphogenetic Protein (ADMP). We report the characterization and functional properties of admp in zebrafish. admp expression profile is consistent with a role in the organizer, including the tail organizer. We studied admp function through overexpression experiments, with the use of a dominant-negative form (TR-ADMP) and of an antisense morpholino-modified oligonucleotide. Our results indicate that the ADMP pathway causes the restriction of anterior and axial fates and that ADMP, BMP2b, and BMP7 pathways have distinct actions but cooperate in establishing proper dorso-ventral regionalization. This is shown by partial rescue of the dorsalized mutant snailhouse and of the ventralized mutant chordino, upon admp and tr-admp RNA injection, respectively. Moreover, ADMP and BMP7 probably form heterodimers as shown by the ability of TR-ADMP and BMP7 to antagonize each other. We observed that a MYC-tagged ADMP was secreted and detected in the extracellular space, suggesting that admp could act at a distance. Simultaneous local inhibition of bmp function at the blastoderm margin and impairment of ADMP secretion led to the induction of secondary head structures, confirming that the two pathways cooperatively regulate organizer formation and activity.

Potential influence of acute CT on inpatient costs in patients with ischemic stroke

RATIONALE AND OBJECTIVES

Patients presenting with ischemic brain symptoms have widely variable outcomes dependent to some degree on the pathologic basis of their stroke syndrome. The purpose of this study was to determine the cost implications of the emergency use of a computed tomographic (CT) protocol comprising unenhanced CT, head and neck CT angiography, and whole-brain CT perfusion.

MATERIALS AND METHODS

By using a retrospective patient database from a tertiary care facility and publicly available cost data, the authors derived the potential savings from the use of CT angiography. CT perfusion, or both at hospital arrival by means of a cost model. The cost of the CT angiography-CT perfusion protocol was determined from Medicare reimbursement rates and compared with that of traditional imaging protocols. Cost savings were estimated as a decrease in the length of stay for most stroke patients, whereas the most benign (lacunar) strokes were assumed to be managed in a non-acute setting. Misdiagnosis cost (erroneously not admitting a patient with nonlacunar stroke) was calculated as the cost of a severe complication. Sensitivity testing included varying the percentage of misdiagnosed patients and admitting patients with lacunar stroke.

RESULTS

The nationwide net savings that would result from the adoption of the CT angiography-CT perfusion protocol are in the $1.2 billion range (-$154 million to $2.1 billion) when patients with lacunar strokes are treated nonacutely and $1.8 billion when those patients are admitted for acute care.

CONCLUSION

The results demonstrate the potential effect of implementing a CT angiography-CT perfusion protocol. In particular, prompt CT angiography-CT perfusion imaging could have an effect on the cost of acute care in the treatment of stroke.

Preparing medical students for a filmless environment: instruction on the preparation of electronic case presentations from PACS

RATIONALE AND OBJECTIVES

As the use of picture archiving and communication systems (PACS) expands and radiology departments become increasingly filmless, it will become increasingly necessary to teach physicians how to use PACS and download diagnostic images. The authors developed an instruction method in which medical students enrolled in a radiology clerkship were taught how to use the PACS, download digital images, and incorporate them into an electronic case presentation. The feasibility and potential benefits of this instructional method were studied prospectively.

MATERIALS AND METHODS

Between June and October 1999, all 36 medical students enrolled in Harvard Medical School's core radiology clerkship at Massachusetts General Hospital, Boston, were required to give an electronic radiology case presentation with images downloaded from the departmental PACS. They were taught how to download images, edit them, and then import them into PowerPoint software. They were also given access to the hospital information system to obtain pertinent clinical information. At the formal presentations, the images were displayed with a liquid crystal display (LCD) projector. The students were surveyed on the Ist and last days of the clerkship regarding their learning experiences.

RESULTS

Before the radiology clerkship, 81% of the students had never given an electronic presentation with computer and LCD projector, 83% had no PACS experience, and 56% had no PowerPoint experience. All students learned to prepare and deliver electronic presentations of radiologic cases downloaded from PACS. Their presentations were informative, innovative, and entertaining, and the images were well displayed. The students praised the instruction highly and thought their new skills would serve them well.

CONCLUSION

Teaching medical students how to prepare and deliver electronic presentations of radiologic cases downloaded from PACS proved to be very feasible and well appreciated by the students.

Patterning the early zebrafish by the opposing actions of bozozok and vox/vent

Fish and frog embryos are patterned along the dorsal-ventral axis during the gastrula stage by opposing gradients of Bmps and Bmp inhibitory proteins. Three transcriptional repressors with partially overlapping expression domains have been proposed to be important mediators of Bmp function in Xenopus. We find that two related factors are expressed in the early zebrafish embryo. Although these factors are considerably divergent from the related Xenopus genes, they are expressed in domains similar to those of their Xenopus relatives throughout embryogenesis. Both of the zebrafish genes, which we have named vox and vent, are potent ventralizing factors in both zebrafish and Xenopus embryos. Using mutants in the Bmp pathway, we find that there are Bmp-dependent and Bmp-independent domains of vox expression, whereas vent is mostly dependent upon Bmp signaling. We show that ectopic vox or vent negatively regulates expression of the early dorsal gene bozozok (boz) and that ectopic boz eliminates vox and vent expression. Moreover, the normal exclusion of vox and vent from the organizer region is lost in boz mutant embryos. Our results show that boz and vox/vent are mutually antagonistic and indicate that the early establishment of the size of the organizer domain is dependent on an interplay between these early expressed transcriptional repressors.

Early intervention and prevention of anxiety disorders in children: results at 2-year follow-up

The Queensland Early Intervention and Prevention of Anxiety Project evaluated a child- and family-focused group intervention for preventing anxiety problems in children. This article reports on 12- and 24-month follow-up data to previously reported outcomes at posttreatment and at 6-month follow-up. A total of 1,786 7- to 14-year-olds were screened for anxiety problems using teacher nominations and children's self-report. After diagnostic interviews, 128 children were selected and assigned to either a 10-week school-based child- and parent-focused psychosocial intervention or a monitoring group. Both groups showed improvements immediately at postintervention and at 6-month follow-up; the improvement was maintained in the intervention group only reducing the rate of existing anxiety disorder and preventing the onset of new anxiety disorders. At 12 months, the groups converged, but the superiority of the intervention group was evident again at 2-year follow-up. Severity of pretreatment diagnoses, gender, and parental anxiety predicted poor initial response to intervention, whereas pretreatment severity was the only predictor of chronicity at 24 months. Overall, follow-up results show that a brief school-based intervention for children can produce durable reductions in anxiety problems.

Early intervention and prevention of anxiety disorders in children: results at 2-year follow-up

The Queensland Early Intervention and Prevention of Anxiety Project evaluated a child- and family-focused group intervention for preventing anxiety problems in children. This article reports on 12- and 24-month follow-up data to previously reported outcomes at posttreatment and at 6-month follow-up. A total of 1,786 7- to 14-year-olds were screened for anxiety problems using teacher nominations and children's self-report. After diagnostic interviews, 128 children were selected and assigned to either a 10-week school-based child- and parent-focused psychosocial intervention or a monitoring group. Both groups showed improvements immediately at postintervention and at 6-month follow-up; the improvement was maintained in the intervention group only reducing the rate of existing anxiety disorder and preventing the onset of new anxiety disorders. At 12 months, the groups converged, but the superiority of the intervention group was evident again at 2-year follow-up. Severity of pretreatment diagnoses, gender, and parental anxiety predicted poor initial response to intervention, whereas pretreatment severity was the only predictor of chronicity at 24 months. Overall, follow-up results show that a brief school-based intervention for children can produce durable reductions in anxiety problems.

Cloning of a cryV-type insecticidal protein gene from Bacillus thuringiensis: the cryV-encoded protein is expressed early in stationary phase

A CryV-type protein (CGCryV) has been isolated from supernatant fluids of Bacillus thuringiensis AB88 cultures. Previous reports have suggested the cryptic nature of the cryV-type genes on the basis of the absence of CryV-type proteins in parasporal crystals. The CryV-type protein reported here is expressed early in stationary phase, and evidence indicates that it is an exported protein. Analysis of the deduced protein sequence from this gene reveals the presence of an N-terminal domain that likely acts as a signal peptide. The CGCryV protein is the first reported case of a delta-endotoxin being a secreted protein, which may influence the biological relevance of these proteins.

Adverse vascular effects of homocysteine are modulated by endothelium-derived relaxing factor and related oxides of nitrogen

Elevated levels of homocysteine are associated with an increased risk of atherosclerosis and thrombosis. The reactivity of the sulfhydryl group of homocysteine has been implicated in molecular mechanisms underlying this increased risk. There is also increasingly compelling evidence that thiols react in the presence of nitric oxide (NO) and endothelium-derived relaxing factor (EDRF) to form S-nitrosothiols, compounds with potent vasodilatory and antiplatelet effects. We, therefore, hypothesized that S-nitrosation of homocysteine would confer these beneficial bioactivities to the thiol, and at the same time attenuate its pathogenicity. We found that prolonged (> 3 h) exposure of endothelial cells to homocysteine results in impaired EDRF responses. By contrast, brief (15 min) exposure of endothelial cells, stimulated to secrete EDRF, to homocysteine results in the formation of S-NO-homocysteine, a potent antiplatelet agent and vasodilator. In contrast to homocysteine, S-NO-homocysteine does not support H2O2 generation and does not undergo conversion to homocysteine thiolactone, reaction products believed to contribute to endothelial toxicity. These results suggest that the normal endothelium modulates the potential, adverse effects of homocysteine by releasing EDRF and forming the adduct S-NO-homocysteine. The adverse vascular properties of homocysteine may result from an inability to sustain S-NO formation owing to a progressive imbalance between the production of NO by progressively dysfunctional endothelial cells and the levels of homocysteine.

S-nitrosylation of tissue-type plasminogen activator confers vasodilatory and antiplatelet properties on the enzyme

Tissue-type plasminogen activator (t-PA) reacts upon exposure to endothelium-derived relaxing factor (EDRF) by way of the enzyme's single free sulfhydryl (Cys-83) to form a stable S-nitrosothiol protein adduct. S-nitrosylation endows t-PA with potent vasodilatory and antiplatelet properties that are accompanied by elevations in intracellular cyclic GMP analogous to those induced by low molecular weight (e.g., S-nitroso amino acid) S-nitrosothiols. Moreover, this chemical modification does not adversely affect the catalytic efficiency of t-PA, the fibrin stimulation of this activity, the binding of t-PA to fibrinogen, or the interaction of the enzyme with its physiologic serine protease inhibitor, plasminogen-activator inhibitor type I. The coupling of vasodilatory, antiplatelet, and fibrinolytic properties in one molecule makes the S-nitrosylated t-PA a unique molecular species and may provide insight into the mechanisms by which the endothelium maintains vessel patency. These data also suggest a pharmacologic approach to treatment of thromboocclusive disorders.

Comparing autistic and normal children along the dimensions of reinforcement maximization, stimulus sampling, and responsiveness to extinction

The purpose of this study was to assess autistic children's ability to maximize reinforcement, sample among available stimuli, and respond to extinction. Responding to five concurrent reinforcement schedules (CRF, FR 2, FR 4, FR 7, and FR 11) was monitored and compared to groups of mental age-matched and chronological age-matched normal children. When a given child consistently selected a given schedule of reinforcement, it was then put on extinction, and both perseveration and responding to the remaining (intact) schedules of reinforcement were monitored. The results showed, first, that while normal children selected the richest schedule of reinforcement, autistics did not maximize reinforcement, typically selecting one of the thinner schedules available. Second, the autistic children sampled less, and less efficiently, than the normal children. Third, the autistic children proved to be much less responsive to extinction, perseverating longer than the normal children before switching to a new reinforcement schedule. Fourth, whenever extinction proved to be a problem in the autistics, it was quickly achieved by a simple change in the stimulus conditions. These results are discussed as possible "keystone" deficits, which may be causally related to many of the behavioral deficits of autism and which might be important target behaviors for treatment.