Frailty, but not cognitive impairment, improves mortality risk prediction among those with chronic kidney disease-a nationally representative study

BACKGROUND

Though older adults with chronic kidney disease (CKD) have a greater mortality risk than those without CKD, traditional risk factors poorly predict mortality in this population. Therefore, we tested our hypothesis that two common geriatric risk factors, frailty and cognitive impairment, and their co-occurrence, might improve mortality risk prediction in CKD.

METHODS

Among participants aged ≥ 60 years from National Health and Nutrition Examination Survey (2011-2014), we quantified associations between frailty (physical frailty phenotype) and global/domain-specific cognitive function (immediate-recall [CERAD-WL], delayed-recall [CERAD-DL], verbal fluency [AF], executive function/processing speed [DSST], and global [standardized-average of 4 domain-specific tests]) using linear regression, and tested whether associations differed by CKD using a Wald test. We then tested whether frailty, global cognitive impairment (1.5SD below the mean), or their combination improved prediction of mortality (Cox models, c-statistics) compared to base models (likelihood-ratios) among those with and without CKD.

RESULTS

Among 3,211 participants, 1.4% were cognitively impaired, and 10.0% were frail; frailty and cognitive impairment co-occurrence was greater among those with CKD versus those without (1.2%vs.0.1%). Frailty was associated with worse global cognitive function (Cohen's d = -0.26SD,95%CI -0.36,-0.17), and worse cognitive function across all domains; these associations did not differ by CKD (pinteractions > 0.05). Mortality risk prediction improved only among those with CKD when accounting for frailty (p[likelihood ratio test] < 0.001) but not cognitive impairment.

CONCLUSIONS

Frailty is associated with worse cognitive function regardless of CKD status. While CKD and frailty improved mortality prediction, cognitive impairment did not. Risk prediction tools should incorporate frailty to improve mortality prediction among those with CKD.

Factors associated with hospital admission and severe outcomes for older patients with COVID-19

Background

Morbidity and death due to coronavirus disease 2019 (COVID‐19) experienced by older adults in nursing homes have been well described, but COVID‐19's impact on community‐living older adults is less studied. Similarly, the previous ambulatory care experience of such patients has rarely been considered in studies of COVID‐19 risks and outcomes.

Methods

To investigate the relationship of advanced age (65+), on risk factors associated with COVID‐19 outcomes in community‐living elders, we identified an electronic health records cohort of older patients aged 65+ with laboratory‐confirmed COVID‐19 with and without an ambulatory care visit in the past 24 months (n = 47,219) in the New York City (NYC) academic medical institutions and the NYC public hospital system from January 2020 to February 2021. The main outcomes are COVID‐19 hospitalization; severe outcomes/Intensive care unit (ICU), intubation, dialysis, stroke, in‐hospital death), and in‐hospital death. The exposures include demographic characteristics, and those with ambulatory records, comorbidities, frailty, and laboratory results.

Results

The 31,770 patients with an ambulatory history had a median age of 74 years; were 47.4% male, 24.3% non‐Hispanic white, 23.3% non‐Hispanic black, and 18.4% Hispanic. With increasing age, the odds ratios and attributable fractions of sex, race–ethnicity, comorbidities, and biomarkers decreased except for dementia and frailty (Hospital Frailty Risk Score). Patients without ambulatory care histories, compared to those with, had significantly higher adjusted rates of COVID‐19 hospitalization and severe outcomes, with strongest effect in the oldest group.

Conclusions

In this cohort of community‐dwelling older adults, we provided evidence of age‐specific risk factors for COVID‐19 hospitalization and severe outcomes. Future research should explore the impact of frailty and dementia in severe COVID‐19 outcomes in community‐living older adults, and the role of engagement in ambulatory care in mitigating severe disease.

A retrospective cohort study of 27,049 polytraumatized patients age 60 and above: identifying changes over 16 years

Aim

In this study, we establish an overview of changes we observed in demographics of older severe trauma patients from 2002 to 2017.

Findings

Trauma mechanism, as well as injury pattern, changed over time. We found length of stay and mortality decreased despite an increase in patient age.

Message

We ascribe this observation mainly to increased use of diagnostic tools and improved treatment algorithms and underline the importance of the implementation of specialized geriatric trauma centers allowing interdisciplinary care.

Purpose

The number of severely injured patients exceeding the age of 60 has shown a steep increase within the last decades. These patients present with numerous co-morbidities, polypharmacy, and increased frailty requiring an adjusted treatment approach. In this study, we establish an overview of changes we observed in demographics of older severe trauma patients from 2002 to 2017.

Methods

A descriptive analysis of the data from the TraumaRegister DGU^® (TR-DGU) was performed. Patients admitted to a level one trauma center in Germany, Austria and Switzerland between 2002 and 2017, aged 60 years or older and with an injury severity score (ISS) over 15 were included. Patients were stratified into subgroups based on the admission: 2002–2005 (1), 2006–2009 (2), 2010–2013 (3) and 2014–2017 (4). Trauma and patient characteristics, diagnostics, treatment and outcome were compared.

Results

In total 27,049 patients with an average age of 73.9 years met the inclusion criteria. The majority were males (64%), and the mean ISS was 27.4. The proportion of patients 60 years or older [(23% (1) to 40% (4)] rose considerably over time. Trauma mechanisms changed over time and more specifically low falls (< 3 m) rose from 17.6% (1) to 40.1% (4). Altered injury patterns were also identified. Length-of-stay decreased from 28.9 (1) to 19.5 days (4) and the length-of-stay on ICU decreased from 17.1 (1) to 12.7 days (4). Mortality decreased from 40.5% (1) to 31.8% (4).

Conclusion

Length of stay and mortality decreased despite an increase in patient age. We ascribe this observation mainly to increased use of diagnostic tools, improved treatment algorithms, and the implementation of specialized trauma centers for older patients allowing interdisciplinary care.

Ordinary injury, big surprise - Traumatic false aneurysm and arteriovenous fistula of the posterior tibial artery after civilian trauma: A case report

Introduction

False traumatic aneurysm (FTA) or pseudoaneurysm and traumatic arteriovenous fistulas (TAVF) are rare pathologies in civilian trauma and mainly result from stabs or gunshot wounds. The posterior tibial artery as site of trauma is very rare.

Presentation of case

We report on a 39-year old female patient who was suffering from combined FTA and TAVF of the posterior tibial artery after falling into a wine glass. CT-imaging as well as duplex ultrasound and selective arteriography were performed, and two stent-grafts were inserted.

Discussion

Based on the presented case, incidence of the described pathology, treatment options and outcomes are discussed.

Conclusion

Adequate imaging in penetrating wounds to the extremities is crucial in order to provide diagnosis and treatment of concomitant lesions.

Acute Peritoneal Dialysis During the COVID-19 Pandemic at Bellevue Hospital in New York City

Background

The COVID-19 pandemic strained hospital resources in New York City, including those for providing dialysis. New York University Medical Center and affiliations, including New York City Health and Hospitals/Bellevue, developed a plan to offset the increased needs for KRT. We established acute peritoneal dialysis (PD) capability, as usual dialysis modalities were overwhelmed by COVID-19 AKI.

Methods

Observational study of patients requiring KRT admitted to Bellevue Hospital during the COVID surge. Bellevue Hospital is one of the largest public hospitals in the United States, providing medical care to an underserved population. There were substantial staff, supplies, and equipment shortages. Adult patients admitted with AKI who required KRT were considered for PD. We rapidly established an acute PD program. A surgery team placed catheters at the bedside in the intensive care unit; a nephrology team delivered treatment. We provided an alternative to hemodialysis and continuous venovenous hemofiltration for treating patients in the intensive-care unit, demonstrating efficacy with outcomes comparable to standard care.

Results

From April 8, 2020 to May 8, 2020, 39 catheters were placed into ten women and 29 men. By June 10, 39% of the patients started on PD recovered kidney function (average ages 56 years for men and 59.5 years for women); men and women who expired were an average 71.8 and 66.2 years old. No episodes of peritonitis were observed; there were nine incidents of minor leaking. Some patients were treated while ventilated in the prone position.

Conclusions

Demand compelled us to utilize acute PD during the COVID-19 pandemic. Our experience is one of the largest recently reported in the United States of which we are aware. Acute PD provided lifesaving care to acutely ill patients when expanding current resources was impossible. Our experience may help other programs to avoid rationing dialysis treatments in health crises.

Terahertz-Driven Stark Spectroscopy of CdSe and CdSe-CdS Core-Shell Quantum Dots

The effects of large external fields on semiconductor nanostructures could reveal much about field-induced shifting of electronic states and their dynamical responses and could enable electro-optic device applications that require large and rapid changes in optical properties. Studies of quasi-dc electric field modulation of quantum dot (QD) properties have been limited by electrostatic breakdown processes observed under high externally applied field levels. To circumvent this, here we apply ultrafast terahertz (THz) electric fields with switching times on the order of 1 ps. We show that a pulsed THz electric field, enhanced by a microslit field enhancement structure (FES), can strongly manipulate the optical absorption properties of a thin film of CdSe and CdSe-CdS core-shell QDs on the subpicosecond time scale with spectral shifts that span the visible to near-IR range. Numerical simulations using a semiempirical tight binding model show that the band gap of the QD film can be shifted by as much a 79 meV during these time scales. The results allow a basic understanding of the field-induced shifting of electronic levels and suggest electro-optic device applications.

Terahertz-Driven Luminescence and Colossal Stark Effect in CdSe-CdS Colloidal Quantum Dots

Optical properties of colloidal semiconductor quantum dots (QDs), arising from quantum mechanical confinement of charge, present a versatile testbed for the study of how high electric fields affect the electronic structure of nanostructured solids. Studies of quasi-DC electric field modulation of QD properties have been limited by electrostatic breakdown processes under high externally applied electric fields, which have restricted the range of modulation of QD properties. In contrast, here we drive CdSe-CdS core-shell QD films with high-field THz-frequency electromagnetic pulses whose duration is only a few picoseconds. Surprisingly, in response to the THz excitation, we observe QD luminescence even in the absence of an external charge source. Our experiments show that QD luminescence is associated with a remarkably high and rapid modulation of the QD bandgap, which changes by more than 0.5 eV (corresponding to 25% of the unperturbed bandgap energy). We show that these colossal energy shifts can be explained by the quantum confined Stark effect even though we are far outside the regime of small field-induced shifts in electronic energy levels. Our results demonstrate a route to extreme modulation of material properties and to a compact, high-bandwidth THz detector that operates at room temperature.

Treatment decisions for older adults with advanced chronic kidney disease

Dialysis initiation rates among older adults, aged 75 years or greater, are increasing at a faster rate than for younger age groups. Older adults with advanced CKD (eGFR < 30 ml/min/1.73 m2) typically lose renal function slowly, often suffer from significant comorbidity and thus may die from associated comorbidities before they require dialysis.A patient's pattern of renal function loss over time in relation to their underlying comorbidities can serve as a guide to the probability of a future dialysis requirement. Most who start dialysis, initiate treatment "early", at an estimated glomerulofiltration rate (eGFR) >10 ml/min/1.73 m2 and many initiate dialysis in hospital, often in association with an episode of acute renal failure. In the US older adults start dialysis at a mean e GFR of 12.6 ml/min/1.73 m2 and 20.6% die within six months of dialysis initiation. In both the acute in hospital and outpatient settings, many older adults appear to be initiating dialysis for non-specific, non-life threatening symptoms and clinical contexts. Observational data suggests that dialysis does not provide a survival benefit for older adults with poor mobility and high levels of comorbidity. To optimize the care of this population, early and repeat shared decision making conversations by health care providers, patients, and their families should consider the risks, burdens, and benefits of dialysis versus conservative management, as well as the patient specific symptoms and clinical situations that could justify dialysis initiation. The potential advantages and disadvantages of dialysis therapy should be considered in conjunction with each patient's unique goals and priorities.In conclusion, when considering the morbidity and quality of life impact associated with dialysis, many older adults may prefer to delay dialysis until there is a definitive indication or may opt for conservative management without dialysis. This approach can incorporate all CKD treatments other than dialysis, provide psychosocial and spiritual support and active symptom management and may also incorporate a palliative care approach with less medical monitoring of lab parameters and more focus on the use of drug therapies directed to relief of a patient's symptoms.

Neuromuscular responses of the plantar flexors to whole-body vibration

Enhanced physical performance following whole-body vibration (WBV) has been attributed to increased muscle activity; however, few studies have measured the mechanisms underlying these changes. The objective of this study was to measure the responsiveness of the Ia pathway as well as contractile properties in 16 young adults (24±2 years, eight men, eight women) following repeated bouts of acute WBV (45 Hz, 2 mm). Hoffman reflexes (H-reflex), compound muscle action potentials (M-wave), and twitch contractile properties were measured prior to and immediately following five 1-minute WBV exposures, and at 3, 5, 10, and 20 minute post-WBV. M-wave and H-reflex amplitudes decreased by 8% (P<.001) and by 46% (P<.05), respectively, whereas peak twitch torque decreased by 9% (P<.01) and rate of twitch torque development slowed 8% (P<.05). Percent voluntary activation and maximal plantar flexor torque were unchanged as a consequence of WBV (P>.05). In response to acute WBV, the root mean square of the soleus electromyography signal (EMG_RMS ) increased by 8%, while the EMG_RMS of the lateral gastrocnemius increased by 3% (P<.05). These data indicate that the responsiveness of the Ia pathway is diminished and contractile function is impaired immediately following WBV, and that the neural mechanisms underlying improved performance following WBV lie in alternative hypotheses possibly involving spindle disfacilitation or Golgi afferent modulation.

Baseline Polymorphisms and Emergence of Drug Resistance in the NS3/4A Protease of Hepatitis C Virus Genotype 1 following Treatment with Faldaprevir and Pegylated Interferon Alpha 2a/Ribavirin in Phase 2 and Phase 3 Studies

Analysis of data pooled from multiple phase 2 (SILEN-C1 to 3) and phase 3 studies (STARTVerso1 to 4) of the hepatitis C virus (HCV) nonstructural protein 3/4A (NS3/4A) protease inhibitor faldaprevir plus pegylated interferon alpha/ribavirin (PR) provides a comprehensive evaluation of baseline and treatment-emergent NS3/4A amino acid variants among HCV genotype-1 (GT-1)-infected patients. Pooled analyses of GT-1a and GT-1b NS3 population-based pretreatment sequences (n = 3,124) showed that faldaprevir resistance-associated variants (RAVs) at NS3 R155 and D168 were rare (<1%). No single, noncanonical NS3 protease or NS4A cofactor baseline polymorphism was associated with a reduced sustained virologic response (SVR) to faldaprevir plus PR, including Q80K. The GT-1b NS3 helicase polymorphism T344I was associated with reduced SVR to faldaprevir plus PR (P < 0.0001) but was not faldaprevir specific, as reduced SVR was also observed with placebo plus PR. Among patients who did not achieve SVR and had available NS3 population sequences (n = 507 GT-1a; n = 349 GT-1b), 94% of GT-1a and 83% of GT-1b encoded faldaprevir treatment-emergent RAVs. The predominant GT-1a RAV was R155K (88%), whereas GT-1b encoded D168 substitutions (78%) in which D168V was predominant (67%). The novel GT-1b NS3 S61L substitution emerged in 7% of virologic failures as a covariant with D168V, most often among the faldaprevir breakthroughs; S61L in combination with D168V had a minimal impact on faldaprevir susceptibility compared with that for D168V alone (1.5-fold difference in vitro). The median time to loss of D168 RAVs among GT-1b-infected patients who did not have a sustained virologic response at 12 weeks posttreatment (non-SVR12) after virologic failure was 5 months, which was shorter than the 14 months for R155 RAVs among GT-1a-infected non-SVR12 patients, suggesting that D168V is less fit than R155K in the absence of faldaprevir selective pressure.

Detecting initiation or risk for initiation of substance use before high school during pediatric well-child check-ups

BACKGROUND

Youth substance use (SU) is prevalent and costly, affecting mental and physical health. American Academy of Pediatrics and Affordable Care Act call for SU screening and prevention. The Youth Risk Index(©) (YRI) was tested as a screening tool for having initiated and propensity to initiate SU before high school (which forecasts SU disorder). YRI was hypothesized to have good to excellent psychometrics, feasibility and stakeholder acceptability for use during well-child check-ups.

DESIGN

A high-risk longitudinal design with two cross-sectional replication samples, ages 9-13 was used. Analyses included receiver operating characteristics and regression analyses.

PARTICIPANTS

A one-year longitudinal sample (N=640) was used for YRI derivation. Replication samples were a cross-sectional sample (N=345) and well-child check-up patients (N=105) for testing feasibility, validity and acceptability as a screening tool.

RESULTS

YRI has excellent test-retest reliability and good sensitivity and specificity for concurrent and one-year-later SU (odds ratios=7.44, CI=4.3-13.0) and conduct problems (odds ratios=7.33, CI=3.9-13.7). Results were replicated in both cross-sectional samples. Well-child patients, parents and pediatric staff rated YRI screening as important, acceptable, and a needed service.

CONCLUSIONS

Identifying at-risk youth prior to age 13 could reap years of opportunity to intervene before onset of SU disorder. Most results pertained to YRI's association with concurrent or recent past risky behaviors; further replication ought to specify its predictive validity, especially adolescent-onset risky behaviors. YRI well identifies youth at risk for SU and conduct problems prior to high school, is feasible and valid for screening during well-child check-ups, and is acceptable to stakeholders.

High-performance shortwave-infrared light-emitting devices using core-shell (PbS-CdS) colloidal quantum dots

Core-shell PbS-CdS quantum dots enhance the peak external quantum efficiency of shortwave-infrared light-emitting devices by up to 50-100-fold (compared with core-only PbS devices). This is more than double the efficiency of previous quantum-dot light-emitting devices operating at wavelengths beyond 1 μm, and results from the passivation of the PbS cores by the CdS shells against in situ photoluminescence quenching.

Organizational HIV monitoring and evaluation capacity rapid needs assessment: the case of Kenya

Introduction

Due to the commitment by the Government of Kenya (GoK) and international donors to address HIV/AIDS, Kenya has some of Africa's most developed health infrastructure for tackling the crisis. Despite this commitment, significant gaps exist in the national HIV/AIDS monitoring and evaluation (M&E) system. To identify these gaps and opportunities for improvement, the U.S. Centers for Disease Control and Prevention funded the Strengthening HIV Strategic Information in Kenya project, which conducted an organizational HIV M&E capacity rapid needs assessment (RNA).

Methods

The project included an in-depth desk review of national documents, policies, tools, and international best practices. National, regional, and district officials from government agencies, development partners, and implementing partners participated in key informant interviews and focus group discussions. Given the large number of regions and districts, purposive sampling was used to select 16 facilities in 8 districts across 2 regions based on the general quality of the reported HIV data and the number of partners supporting the regions.

Results

RNA findings revealed tremendous improvements at the national level and in the various subsystems that contribute to the overall HIV strategic information. There also were significant gaps, including in a lack of M&E guidelines, parallel reporting systems, feedback given to subnational levels, and data use and general data management and use capacity at subnational levels.

Conclusion

An urgent need exists for the development of national M&E guidelines and a comprehensive training curriculum. To ensure success further, capacity building for subnational levels should be conducted and feedback channels to subnational staff should be established and maintained.

Interspecies Uptake of Polymeric Microspheres

Particle uptake into intestinal tissue has seen increasing attention due to its implications in drug delivery. We attempted to observe a delivery system in vivo and examine uptake in different species. Microspheres were fabricated from polymers including polyanhydrides and delivered to an isolated loop of intestine in several species. The microspheres contained a dye either conjugated to a protein or incorporated freely and were used to qualitatively detect and locate the spheres in the villi of the length of the small intestine. Microspheres were dispersed, sized by a Coulter particle size analyzer, and characterized by confocal and cross-polarized light microscopy, FTIR and SEM. Coulter analysis revealed microspheres to be generally less than 5 microns in diameter. SEM typically showed homogeneous morphology among groups of microspheres. In vivo uptake experiments were performed in rodents, pigs, and ruminants using various microsphere formulations. Microspheres were delivered into the proximal end of the jejunum of anesthetized animals and allowed adequate transit time to be taken up. Animals were euthanized at various time points for explantation of tissue and sampling of blood. Excised samples were embedded inq polyvinyl alcohol, frozen, and cut into sections ranging between 7 and 14 μm in thickness. Our method of incorporating dyes allowed for simultaneous visualization by visible light microscopy and confocal laser scanning microscopy. Two-fluorochrome fluorescence of the microspheres and optical sectioning confirmed the presence of microspheres within intestinal tissue. The amount of uptake depended on the animal model, the duration of the experiment, and the composition of the microsphere. An assay for either the fluorescent dye, the protein attached to it, or the polymer encapsulating it may enable us to determine intracellular concentrations of mierospheres for the quantification of uptake.

Oxidative stress and DNA damage in agricultural workers

Oxidative stress and DNA damage have been proposed as mechanisms linking pesticide exposure to health effects such as cancer and neurological diseases. A pilot study of pesticide applicators and farm workers working in the fruit orchards of Oregon (i.e., apples, pears) was conducted to examine the relationship between organophosphate (OP) pesticide exposure and oxidative stress and DNA damage. Urine samples were analyzed for OP metabolites and 8-hydroxy-2'-deoxyguanosine (8-OH-dG). Lymphocytes were analyzed for oxidative DNA repair activity and DNA damage (Comet assay) and serum analyzed for lipid peroxides (i.e., malondialdehyde [MDA]). Cellular DNA damage in agricultural workers was validated using lymphocyte cell cultures. Urinary OP metabolites were significantly higher in farm workers and applicators (p < .001) when compared to controls. 8-OH-dG levels were 8.5 times and 2.3 times higher in farm workers and applicators, respectively, than in controls. Serum MDA levels were 4.9 times and 24 times higher in farm workers and applicators, respectively, than in controls. DNA damage and oxidative DNA repair were significantly greater in lymphocytes from applicators and farm workers when compared with controls. A separate field study showed that DNA damage was also significantly greater (p < .001) in buccal cells (i.e., leukocytes) collected from migrant farm workers working with fungicides in the berry crops in Oregon. Markers of oxidative stress (i.e., reactive oxygen species, reduced levels of glutathione) and oxidative DNA damage were also observed in lymphocyte cell cultures treated with an OP. The findings from these in vivo and in vitro studies indicate that pesticides induce oxidative stress and DNA damage in agricultural workers. These biomarkers may be useful for increasing our understanding of the link between pesticides and cancer.

Engaging partners to initiate evaluation efforts: tactics used and lessons learned from the prevention research centers program

BACKGROUND

The Centers for Disease Control and Prevention's (CDC's) Prevention Research Centers (PRC) Program underwent a 2-year evaluation planning project using a participatory process that allowed perspectives from the national community of PRC partners to be expressed and reflected in a national logic model.

CONTEXT

The PRC Program recognized the challenge in developing a feasible, useable, and relevant evaluation process for a large, diverse program. To address the challenge, participatory and utilization-focused evaluation models were used.

METHODS

Four tactics guided the evaluation planning process: 1) assessing stakeholders' communication needs and existing communication mechanisms and infrastructure; 2) using existing mechanisms and establishing others as needed to inform, educate, and request feedback; 3) listening to and using feedback received; and 4) obtaining adequate resources and building flexibility into the project plan to support multifaceted mechanisms for data collection.

CONSEQUENCES

Participatory methods resulted in buy-in from stakeholders and the development of a national logic model. Benefits included CDC's use of the logic model for program planning and development of a national evaluation protocol and increased expectations among PRC partners for involvement. Challenges included the time, effort, and investment of program resources required for the participatory approach and the identification of whom to engage and when to engage them for feedback on project decisions.

INTERPRETATION

By using a participatory and utilization-focused model, program partners positively influenced how CDC developed an evaluation plan. The tactics we used can guide the involvement of program stakeholders and help with decisions on appropriate methods and approaches for engaging partners.

Biomarkers of oxidative stress and DNA damage in agricultural workers: a pilot study

Oxidative stress and DNA damage have been proposed as mechanisms linking pesticide exposure to health effects such as cancer and neurological diseases. A study of pesticide applicators and farmworkers was conducted to examine the relationship between organophosphate pesticide exposure and biomarkers of oxidative stress and DNA damage. Urine samples were analyzed for OP metabolites and 8-hydroxy-2'-deoxyguanosine (8-OH-dG). Lymphocytes were analyzed for oxidative DNA repair activity and DNA damage (Comet assay), and serum was analyzed for lipid peroxides (i.e., malondialdehyde, MDA). Cellular damage in agricultural workers was validated using lymphocyte cell cultures. Urinary OP metabolites were significantly higher in farmworkers and applicators (p<0.001) when compared to controls. 8-OH-dG levels were 8.5 times and 2.3 times higher in farmworkers or applicators (respectively) than in controls. Serum MDA levels were 4.9 times and 24 times higher in farmworkers or applicators (respectively) than in controls. DNA damage (Comet assay) and oxidative DNA repair were significantly greater in lymphocytes from applicators and farmworkers when compared with controls. Markers of oxidative stress (i.e., increased reactive oxygen species and reduced glutathione levels) and DNA damage were also observed in lymphocyte cell cultures treated with an OP. The findings from these in vivo and in vitro studies indicate that organophosphate pesticides induce oxidative stress and DNA damage in agricultural workers. These biomarkers may be useful for increasing our understanding of the link between pesticides and a number of health effects.

Definitions of sedentary in physical-activity-intervention trials: a summary of the literature

This review describes the definitions of sedentary used to screen community-dwelling adults in physical-activity-intervention trials published from 2000 to 2005. Results of 42 trials showed that definitions of sedentary varied from <20 to <150 min/week of physical activity, and few reported the type (work, household, or leisure) or intensity of activity that was used to screen participants. The range of "sedentary" samples makes it difficult to compare trial results or generalize findings. Published reports of exercise trials would be more useful to practitioners and researchers if they included an explicit description of the cut point used to define sedentary adults in the sample, in terms of maximum minutes or days per week of activity and the wording of the screening measure in terms of type and intensity of activity.

Motivational Interviewing to Increase Physical Activity in Long-Term Cancer Survivors

BACKGROUND

Physical activity can confer many benefits on cancer survivors, including relief of persistent symptoms related to cancer treatment.

OBJECTIVES

To evaluate the effect of a motivational interviewing (MI) intervention on increasing physical activity (Community Healthy Activities Model Program for Seniors questionnaire) and improving aerobic fitness (6-minute walk), health (Medical Outcomes Study Short-Form 36), and fatigue (Schwartz Cancer Fatigue Scale) in cancer survivors. A secondary purpose was to evaluate whether the effect of MI on physical activities depended on self-efficacy.

METHODS

Fifty-six physically inactive adult cancer survivors (mean=42 months since completion of treatment) were assigned randomly to intervention and control groups. The MI intervention consisted of one in-person counseling session followed by two MI telephone calls over 6 months. Control group participants received two telephone calls without MI content. Outcomes were measured at baseline, 3 months, and 6 months, and were analyzed using multilevel modeling.

RESULTS

The results of the MI intervention explained significant group differences in regular physical activities (measured in caloric expenditure per week), controlling for time since completion of cancer treatment (p<.05). Aerobic fitness, physical and mental health, and fatigue were not different between groups. In the intervention group, individuals with high self-efficacy for exercise at baseline increased their physical activity more than those with low self-efficacy (p<.05). In the control group, increases in physical activity did not depend on self-efficacy.

DISCUSSION

Use of MI may increase physical activity in long-term cancer survivors, especially in persons with high self-efficacy for exercise. Multilevel modeling analysis revealed individual changes that would not have been shown by analysis of group means. Future studies with larger samples or more intense MI interventions may show changes in aerobic fitness, physical and mental health, and fatigue.

Neurobehavioral performance of adult and adolescent agricultural workers

There are many occupational hazards associated with working in agriculture including risk of injury and exposure to pesticides. Research examining neurobehavioral effects of pesticide exposure have focused primarily on the acute effects in adults working in agriculture. Organophosphate poisoned populations have shown a consistent pattern of deficits when compared to a non-exposed or non-poisoned population on measures of motor speed and coordination, sustained attention, and information processing speed. Fewer studies have examined the effect of long-term low-level exposure on nervous system functioning in agricultural workers. Pesticides are thought to pose a considerably higher risk to children than to adults, yet little is known about the extent or magnitude of health problems related to occupational exposure to pesticides in children and adolescents. The present study compared the neurobehavioral performance of adolescents and adults working in agriculture and examined the impact of years working in agriculture on neurobehavioral performance. One hundred seventy-five Hispanic adolescent and adults completed a neurobehavioral test battery consisting of 10 computer-based tests measuring attention, response speed, coordination and memory. Age, gender, school experience, and years working in agriculture all impacted performance on the neurobehavioral tests. Comparison of adult and adolescents did not reveal decreased neurobehavioral performance in adolescents. On several tests the adolescents performed better than adult counterparts. The adolescents and adults were engaged in comparable agricultural working environments at the time of the neurobehavioral testing. These findings suggest that, at the time of exposure to pesticides, adolescents are not more vulnerable to the effects of working in agriculture. Evidence from this study suggests that cumulative exposure to low levels of pesticides over many years of agricultural work is associated with neurological impairment as measured by the Selective Attention, Symbol-Digit, Reaction Time tests. Experience handling pesticides was also associated with deficits in neurobehavioral performance.

Schizophrenia, Neurobiology and the Methodology of Systemic Modeling

Progress in the pharmacological treatment of schizophrenia is dependent on the extent of our understanding of the brain as the basis of this disease. Detailed examination of neurobiological data shows that only a systemic approach will integrate this wealth of information. For this reason, the steps involved in model building should be clarified, as further progress will necessitate closer cooperation between neuropsychiatrists, neurobiologists and systems scientists.

Neurobehavioral performance in preschool children from agricultural and non-agricultural communities in Oregon and North Carolina

Organophosphate (OP) pesticides produce acute toxic effects but little is known about low-level chronic exposures. Latino children of agricultural workers have a high risk of exposure to pesticides because of the close proximity of their homes to fields where pesticides are applied and from take-home exposure. Neurobehavioral performance of preschool children from agricultural (AG) communities was compared to performance of those from non-agricultural (Non-AG) communities in Oregon and North Carolina. Seventy-eight children aged 48-71 months completed a battery of neurobehavioral tests two times, approximately 1 month apart. Multiple regression revealed that the AG children performed poorer on measures of response speed (Finger Tapping) and latency (Match-to-Sample) compared to the Non-AG children. These results demonstrate modest differences in AG children compared to Non-AG children that are consistent with functional effects seen in adults exposed to low concentrations of OP pesticides. Just as was the case following early research on adults poisoned by pesticides, this study points to the need for additional investigations to test the hypothesis that low-concentration OP exposures affect acquisition of test performance, response speed and latency in children of agricultural workers.

Variation in organophosphate pesticide metabolites in urine of children living in agricultural communities

Children of migrant farmworkers are at increased risk of exposure to organophosphate pesticides because of "carry-home" transport processes and residential location. Although this at-risk status is generally recognized, few available reports describe the extent of this exposure among agricultural communities. We quantified dialkyl phosphate (DAP) levels in serial samples of urine from 176 children, 2-6 years of age, in three Oregon communities hosting differing agricultural industries: pears, cherries, and fruit berries. Up to three spot samples of urine were collected from children at the beginning, mid-point, and end of their parents' work seasons. The median levels of dimethylthiophosphate (DMTP), the most commonly detected metabolite, was significantly higher in urine samples from children in each of the three agricultural communities (17.5, 19.0, and 41.0 ng/mL) relative to a reference group of children who lived in an urban community and whose parents did not work in agriculture (6.5 ng/mL; Kruskal-Wallis, p < 0.001). After controlling for age, sex, and weight, the median level of DMTP in children in the pear community was 1.92 times higher than the level in children of the berry community [95% confidence interval (CI), 1.14-3.23] and 1.75 times higher than the level in children of the cherry community (95% CI, 0.95-3.23). We observed increasing levels of DMTP across the work season only within the berry community. Levels decreased in the cherry community and remained constant in the pear community. Substantial temporal variation within the children followed demonstrates the need for multiple urine samples to most accurately characterize longer term and/or cumulative exposure. The observed variability in urinary DAP levels, between communities and over time, could be attributed to the types and amounts of organophosphate pesticides used, the timing of applications and degradation of residues in the environment, work operations and hygiene practices, the proximity of housing to orchards and fields, or the movement of these working families. Additional studies of variation in pesticide exposure across agricultural regions are needed.

L-Thyroxin-Hochdosierung bei therapieresistenter Depression

In a depression unit in a state hospital, 28 patients who had failed in six antidepressant strategies were treated with L-thyroxine at an average dose of 350 micro g/die. Outcomes were moderate in 39.3% and very good in 21.5%, corresponding to 21-item HAMD scores of < or =16 and < or =8 and clinical judgement. Of all patients, 39.3% had to stop treatment due to nonresponse or side effects. Follow-up of all responders to treatment was conducted 45.2 weeks after discharge. Those 28.6% patients who had stopped treatment had significantly more readmissions, i.e., 62.5%, vs none in those who continued, whereas subjective clinical ratings did not differ between the two groups. In contrast to the literature not finding serious side effects in 70 mainly bipolar patients, we found cardial arrhythmia in 10.7% of inpatients and 7.1% of follow-up patients that was serious enough to discontinue treatment. In conclusion, systematic investigation of high-dose L-thyroxine treatment in treatment-resistant depression seems promising and necessary.

The gene expression sequence of radiated mucosa in an animal mucositis model

Oral mucositis is a common, dose-limiting, acute toxicity of radiation therapy administered for the treatment of cancers of the head and neck. Accumulating data would suggest that the pathogenesis of mucositis is complex and involves the sequential interaction of all cell types of the oral mucosa, as well as a number of cytokines and elements of the oral environment. While a number of studies have reported on gene expression of particular cell types in response to radiation, the overall response of irradiated mucosa has only been evaluated in a limited way. The present study was undertaken to evaluate the expression of a target group of genes using RNA quantification assays and, more broadly, to assess patterns of mucosal gene expression using DNA microarray hybridization. Our results demonstrate the sequential upregulation of a series of genes that, when taken collectively, suggest an intricate functional interaction.

Determinants of improvement in epicardial flow and myocardial perfusion for ST elevation myocardial infarction; insights from TIMI 14 and InTIME-II

BACKGROUND

When evaluating new reperfusion regimens for ST elevation MI, it is important to adjust for factors that influence the likelihood of achieving normal epicardial flow and complete ST resolution.

METHODS AND RESULTS

A total of 610 patients from TIMI 14 contributed to the angiographic analyses. The electrocardiographic analyses were based on 544 patients from TIMI 14 and 763 patients from InTIME-II. For each hour from onset of symptoms to initiation of pharmacological reperfusion, the odds of achieving TIMI 3 flow at 90 min or complete ST resolution at 60-90 min decreased significantly (P=0.03). Anterior location of infarction was associated with a reduction in the odds of achieving TIMI 3 flow or complete ST resolution. The use of abciximab as part of the reperfusion regimen significantly increased the odds of TIMI 3 flow (P=0.01) and ST resolution (P<0.001). The fibrinolytic administered (alteplase, reteplase, lanoteplase) did not influence the odds of TIMI 3 flow or ST resolution after adjusting for time to treatment, infarct location, and use of abciximab.

CONCLUSIONS

The influence of time from symptoms on epicardial flow and STRES reinforces the need for increased efforts to reduce treatment delays in patients with ST elevation MI. The significant benefits of abciximab with respect to facilitation of epicardial and myocardial reperfusion are evident even after adjusting for time to treatment and infarct location. To adjust for determinants of success of reperfusion regimens, phase II trials evaluating new drug combinations should consider using a randomization scheme that stratifies patients based on infarct location and time from symptoms.

Preliminary study on the use of an inhomogeneous anthropomorphic Fricke gel phantom and 3D magnetic resonance dosimetry for verification of IMRT treatment plans

An inhomogeneous anthropomorphic phantom of the human thorax including lungs and spine was developed for verification of three-dimensional (3D) intensity-modulated radiotherapy (IMRT). The phantom and spinal cord were filled with undiluted Fricke gel, whereas the lungs were filled with a special low-density Fricke gel. Based on a computed tomography scan of the phantom, an intensity-modulated stereotactic radiotherapy plan for a bronchial carcinoma was calculated using an inverse planning system (KonRad, DKFZ Heidelberg, Germany). The plan consisted of seven beams delivered in a step and shoot technique out of 67 sub-fields. Immediately after irradiation 3D magnetic resonance (MR) imaging of the phantom was performed using a special pulse sequence for T1 relaxometry. From the MR image data maps of the longitudinal relaxation rate R1 = 1/T1 were calculated. The R1 maps were converted to dose-proportional image data and compared to planning data. Measurement and planning show good agreement in regions of standard Fricke gel with an average deviation below 5%. In regions of the low-density Fricke gel, deviations are higher due to a decreased signal-to-noise ratio in the MR measurement. In these areas also a different sensitivity of the dose response was observed as compared to standard Fricke gel. The inhomogeneous thorax phantom has proven to be a useful pre-clinical tool for 3D methodical verifications.

Impact of abciximab versus eptifibatide on length of hospital stay for PCI patients

The purpose of this study is to compare the profile of percutaneous coronary intervention (PCI) patients who receive abciximab versus eptifibatide, as well as to compare the effect of abciximab versus eptifibatide on hospital length of stay. Retrospective data were obtained from HCIA's Clinical Pathways Database on 5,446 coronary angioplasty patients who were administered either abciximab or eptifibatide. Estimation was conducted via a two-stage sample selection model. In the first stage, a probit regression was employed to determine which factors were associated with a higher probability of being administered abciximab versus eptifibatide. In the second stage, a negative binomial model was used to estimate the impact of a wide range of factors (selection of GPIIb/IIIa, patient demographics, insurance provider, health conditions, admission information, and hospital characteristics) on total hospital length of stay, as well as on postprocedural length of stay. After controlling for high-risk indications and other sources of selection bias, results indicate that receipt of abciximab was associated with a significantly shorter length of total hospital stay (0.83 fewer days; P < 0.001) than receipt of eptifibatide. Additionally, receipt of abciximab was found to be associated with a significantly shorter postprocedural hospital length of stay (0.48 fewer days; P = 0.002) compared to receipt of eptifibatide. Results of this study indicate that PCI patients who are administered abciximab versus eptifibatide have a significantly shorter length of hospital stay (both total and postprocedural). This finding is important since hospital length of stay reflects the occurrence of complications and has been found to be directly related to the resources consumed during in-patient management of patients. Cathet Cardiovasc Intervent 2001;53:296-303.

Structural and functional dissection of the cytoplasmic domain of the transmembrane adaptor protein SIT (SHP2-interacting transmembrane adaptor protein)

SIT (SHP2-interacting transmembrane adaptor protein) is a recently identified transmembrane adaptor protein, which is expressed in lymphocytes. Its structural properties, in particular the presence of five potential tyrosine phosphorylation sites, suggest involvement of SIT in TCR-mediated recruitment of SH2 domain-containing intracellular signaling molecules to the plasma membrane. Indeed, it has recently been demonstrated that SIT inducibly interacts with the SH2-containing protein tyrosine phosphatase 2 (SHP2) via an immunoreceptor tyrosine-based inhibition motif (ITIM). Moreover, SIT is capable to inhibit TCR-mediated signals proximal of activation of protein kinase C. However, inhibition of T cell activation by SIT occurs independently of SHP2 binding. The present study was performed to further characterize the molecular interaction between SIT and intracellular effector molecules and to identify the protein(s) mediating its inhibitory function. We demonstrate that SIT not only interacts with SHP2 but also with the adaptor protein Grb2 via two consensus YxN motifs. However, mutation of both Grb2-binding sites also does not influence the inhibitory function of SIT. In contrast, mutation of the tyrosine-based signaling motif Y(168) ASV completely abrogates the ability of SIT to inhibit T cell activation. Co-precipitation experiments revealed that the tyrosine kinase p50(csk) could represent the negative regulatory effector molecule that binds to this motif.

[Introduction of the new DRG-based reimbursement system in German hospitals--a difficult operation? Experiences and possible solutions from the viewpoint of trauma surgery]

Until recently the costs of patients in German hospitals have mainly been calculated according to the length of hospital stay. However, in December 1999, a dramatic change was announced in the social laws in the "Gesundheitsreform 2000." Beginning in 2003 a prospective payment system based on the classification of the "Australian Refined DRGs (AR-DRG)" will be introduced. DRGs are already used in quite a lot of industrialized countries and basically are "per case" payment systems that group patients with homogeneous average costs based on the diagnoses and procedures performed in the hospital. When preparing for this new system, the clinician has a lot of additional tasks. Besides correctly documenting all clinical findings with the ICD-10 Diagnoses and the German OPS301 procedure codes, a knowledge of the economical impact of the clinical decision is absolutely crucial. The most important task is the optimizing of all clinical treatment processes (e.g. by the introduction of clinical pathways), because only hospitals that can do highly efficient treatment will be able to survive in the upcoming competitive situation. In the Krankenhaus München--Schwabing DRGs have been used as a benchmarking tool since 1997. Based on valuable experience, many direct measures to optimize efficiency have been taken. Especially in patients with multiple trauma, it became evident that the use of efficient and standardized treatment can bring economic gain without loss of quality.

Impact of abciximab versus tirofiban on hospital length of stay for PCI patients

The purpose of this retrospective study was to examine in a naturalistic setting the effect of abciximab versus tirofiban on hospital length of stay for patients undergoing percutaneous coronary intervention (PCI). Retrospective data were obtained from HCIASach's Clinical Pathways Database on 5,560 PCI patients who were administered either abciximab or tirofiban. Multivariate analysis was used to control for a wide range of factors (GPIIb/IIIa selection, patient demographics, insurance provider, health conditions, admission information, and hospital characteristics) that may influence hospital length of stay. Estimation was conducted via a two-stage sample selection model. After controlling for high-risk indications and sources of selection bias, results indicate that receipt of abciximab was associated with significantly shorter lengths of hospital stays compared to tirofiban (1.01 fewer days; p < 0.001). In a subgroup analysis of patients having an acute myocardial infarction (AMI; n = 2,593), receipt of abciximab was also found to be associated with significantly shorter hospital stays compared to tirofiban (0.60 fewer days; p < 0.001). Results of this study indicate that patients who are administered abciximab versus tirofiban have significantly shorter hospital stays. This reduction in length of stay may imply potential cost offsets for PCI patients who receive abciximab.

High-performance multiplex SNP analysis of three hemochromatosis-related mutations with capillary array electrophoresis microplates

An assay is described for high-throughput single nucleotide polymorphism (SNP) genotyping on a microfabricated capillary array electrophoresis (CAE) microchip. The assay targets the three common variants at the HFE locus associated with the genetic disease hereditary hemochromatosis (HHC). The assay employs allele-specific PCR (ASPCR) for the C282Y (845g->a), H63D (187c->g), and S65C (193a->t) variants using fluorescently-labeled energy-transfer (ET) allele-specific primers. Using a 96-channel radial CAE microplate, the labeled ASPCR products generated from 96 samples in a reference Caucasian population are simultaneously separated with single-base-pair resolution and genotyped in under 10 min. Detection is accomplished with a laser-excited rotary four-color fluorescence scanner. The allele-specific amplicons are differentiated on the basis of both their size and the color of the label emission. This study is the first demonstration of the combined use of ASPCR with ET primers and microfabricated radial CAE microplates to perform multiplex SNP analyses in a clinically relevant population.

Combination reperfusion therapy with abciximab and reduced dose reteplase: results from TIMI 14. The Thrombolysis in Myocardial Infarction (TIMI) 14 Investigators

Aims Abciximab has previously been shown to enhance thrombolysis and improve myocardial perfusion when combined with reduced doses of alteplase. The purpose of the reteplase phase of TIMI 14 was to evaluate the effects of abciximab when used in combination with a reduced dose of reteplase for ST-elevation myocardial infarction. Methods and Results Patients (n=299) with ST-elevation myocardial infarction were treated with aspirin and randomized to a control arm with standard dose reteplase (10+10 U given 30 min apart) or abciximab (bolus of 0.25 mg. kg(-1)and 12-h infusion of 0.125 microg. kg(-1). min(-1)) in combination with reduced doses of reteplase (5+5 U or 10+5 U). Control patients received standard weight-adjusted heparin (bolus of 70 U. kg(-1); infusion of 15 U. kg(-1). h(-1)), while each of the combination arms with abciximab and reduced dose reteplase received either low dose heparin (bolus of 60 U. kg(-1); infusion of 7 U. kg(-1). h(-1)) or very low dose heparin (bolus of 30 U. kg(-1); infusion of 4 U. kg(-1). h(-1)). The rate of TIMI 3 flow at 90 min was 70% for patients treated with 10+10 U of reteplase alone (n=87), 73% for those treated with 5+5 U of reteplase with abciximab (n=88), and 77% for those treated with 10+5 U of reteplase with abciximab (n=75). Complete (>/=70%) ST resolution at 90 min was seen in 56% of patients receiving a reduced dose of reteplase in combination with abciximab compared with 48% of patients receiving reteplase alone. Conclusions Reduced doses of reteplase when administered in combination with abciximab were associated with higher TIMI 3 flow rates than reported previously for reduced doses of reteplase without abciximab and were at least as high as for full dose reteplase alone