Cost of Implementing an Evidence-Based Intervention to Support Safer Use of Antipsychotics in Youth

To estimate the cost of implementing a clinical program designed to support safer use of antipsychotics in children and adolescents (youth) age 3-17 years at the time of initiating an antipsychotic medication. We calculate the costs of implementing a psychiatric consultation and navigation program for youth prescribed antipsychotic medications across 4 health systems, which included an electronic health record (EHR) decision support tool, consultation with a child and adolescent psychiatrist, and up to 6 months of behavioral health care navigation, as well as telemental health for patients (n = 348). Cost data were collected for both start-up and ongoing intervention phases and are estimated over a 1-year period. Data sources included study records and time-in-motion reports, analyzed from a health system perspective. Costs included both labor and nonlabor costs (2019 US dollars). The average total start-up and ongoing costs per health system were $34,007 and $185,174, respectively. The average total cost per patient was $2,128. The highest average ongoing labor cost components were telemental health ($901 per patient), followed by child and adolescent psychiatrist consultation ($659), and the lowest cost component was primary care/behavioral health provider time to review/respond to the EHR decision support tool and case consultation ($24). For health systems considering programs to promote safer and targeted use of antipsychotics among youth, this study provides estimates of the full start-up and ongoing costs of an EHR decision support tool, psychiatric consultation service, and psychotherapeutic services for patients and families.Trial registration: Clinicaltrials.gov, NCT03448575.

Prevalence of unnecessary antibiotic use in European hospitals – a systematic review

Background

Antibiotics (AB) are essential to modern day medicine as prophylaxis and therapy. Yet, unnecessary use has various negative effects on individual and global health, such as antimicrobial resistance (AMR) and contribution to high greenhouse gas (GHG) emissions of the healthcare sector. This systematic review provides an overview of unnecessary AB use in European hospitals in order to present possible ways forward.

Methods

The systematic review followed PRISMA guidelines, included as databases were: Embase, ProQuest Environmental Science Collection, PubMed, ScienceDirect, Scopus and Web of Science. Studies conducted among adult in-patients in EU/EEA countries were included if they provided assessment methodology, included a clear standard of measurement and chart reviews were used as evaluation basis.

Results

Fifty-six included studies were categorised into the following three groups: (1) Studies using an established evaluation method; 20 studies belong to this group, 18 used the same, established approach. Eleven of these studies performed an observational audit, while the interventions in the remaining studies were of educational or advisory nature. Unnecessary AB use ranged from 1.5% to 51% of all observed prescriptions. Outcomes of interventions showed great variation of effects on unnecessary use (-34.7% - +11.6). (2) Studies using a newly developed, clearly stated evaluation method (4 studies); (3) Studies which conform with established evaluation methods but the processes were not specified (32 studies). Results are subject to further analysis.

Conclusions

The studies included reported a great range of unnecessary AB use in adult in-patients, for both prophylactic and therapeutic indications. Evaluation methods of unnecessary AB use vary greatly between studies. In future research, comprehensive application of established approaches is essential for better overview and identification of key areas for AMR and GHG emission reduction activities.

Key messages

• Unnecessary antibiotic use varies greatly among studies conducted in European adult in-patients.

• In future research, wider application of established evaluation methods will improve comparability and targeting of interventions.

Reducing Sitting Time in Obese Older Adults: The I-STAND Randomized Controlled Trial

BACKGROUND

The authors tested the efficacy of the "I-STAND" intervention for reducing sitting time, a novel and potentially health-promoting approach, in older adults with obesity.

METHODS

The authors recruited 60 people (mean age = 68 ± 4.9 years, 68% female, 86% White; mean body mass index = 35.4). The participants were randomized to receive the I-STAND sitting reduction intervention (n = 29) or healthy living control group (n = 31) for 12 weeks. At baseline and at 12 weeks, the participants wore activPAL devices to assess sitting time (primary outcome). Secondary outcomes included fasting glucose, blood pressure, and weight. Linear regression models assessed between-group differences in the outcomes.

RESULTS

The I-STAND participants significantly reduced their sitting time compared with the controls (-58 min per day; 95% confidence interval [-100.3, -15.6]; p = .007). There were no statistically significant changes in the secondary outcomes.

CONCLUSION

I-STAND was efficacious in reducing sitting time, but not in changing health outcomes in older adults with obesity.

Multimodal Characterization of the Late Effects of Traumatic Brain Injury: A Methodological Overview of the Late Effects of Traumatic Brain Injury Project

Epidemiological studies suggest that a single moderate-to-severe traumatic brain injury (TBI) is associated with an increased risk of neurodegenerative disease, including Alzheimer's disease (AD) and Parkinson's disease (PD). Histopathological studies describe complex neurodegenerative pathologies in individuals exposed to single moderate-to-severe TBI or repetitive mild TBI, including chronic traumatic encephalopathy (CTE). However, the clinicopathological links between TBI and post-traumatic neurodegenerative diseases such as AD, PD, and CTE remain poorly understood. Here, we describe the methodology of the Late Effects of TBI (LETBI) study, whose goals are to characterize chronic post-traumatic neuropathology and to identify in vivo biomarkers of post-traumatic neurodegeneration. LETBI participants undergo extensive clinical evaluation using National Institutes of Health TBI Common Data Elements, proteomic and genomic analysis, structural and functional magnetic resonance imaging (MRI), and prospective consent for brain donation. Selected brain specimens undergo ultra-high resolution ex vivo MRI and histopathological evaluation including whole-mount analysis. Co-registration of ex vivo and in vivo MRI data enables identification of ex vivo lesions that were present during life. In vivo signatures of postmortem pathology are then correlated with cognitive and behavioral data to characterize the clinical phenotype(s) associated with pathological brain lesions. We illustrate the study methods and demonstrate proof of concept for this approach by reporting results from the first LETBI participant, who despite the presence of multiple in vivo and ex vivo pathoanatomic lesions had normal cognition and was functionally independent until her mid-80s. The LETBI project represents a multidisciplinary effort to characterize post-traumatic neuropathology and identify in vivo signatures of postmortem pathology in a prospective study.

Reducing Sedentary Time for Obese Older Adults: Protocol for a Randomized Controlled Trial

Background

Older adults have high rates of obesity and are prone to chronic health conditions. These conditions are in part due to high rates of sedentary time (ST). As such, reducing ST could be an innovative strategy for improving health outcomes among obese older adults. To test this theory, we developed a novel, technology-enhanced intervention to reduce sitting time (I-STAND) and pilot tested it to assess the feasibility, acceptability, and preliminary effects of the intervention on ST and biometric outcomes.

Objective

The current paper aims to describe the rationale, design, and methods of the I-STAND sitting reduction pilot trial.

Methods

Older adults with obesity (n=60) were recruited from a large health care system and randomized to receive I-STAND or a healthy living intervention. I-STAND combined personal coaching with a technology-enhanced intervention (Jawbone UP band) to cue breaks from sitting. Participants completed self-report and biometric assessments at baseline and 3 months. Additional qualitative results were collected from a subset of I-STAND participants (n=22) to further inform the feasibility and acceptability of the interventions. The primary outcome was total hours of daily sitting time measured by the activPAL device. Secondary outcomes included sit-to-stand transitions, bouts of sitting longer than 30 minutes, physical function, blood pressure, fasting glucose, cholesterol, and depressive symptoms.

Results

Study enrollment has ended and data processing is underway.

Conclusions

Data from randomized trials on sitting reduction are needed to inform novel approaches to health promotion among older adults with obesity. Our trial will help fill this gap. The methods used in our study can guide future research on using technology-based devices to assess or prompt sedentary behavior reduction, or those interested in behavioral interventions targeting obese older adults with novel approaches

Trial Registration

ClinicalTrials.gov: NCT02692560; https://clinicaltrials.gov/ct2/show/NCT02692560 (Archived by WebCite at http://www.webcitation.org/6wppLTWAl)

Neuropathological and transcriptomic characteristics of the aged brain

As more people live longer, age-related neurodegenerative diseases are an increasingly important societal health issue. Treatments targeting specific pathologies such as amyloid beta in Alzheimer’s disease (AD) have not led to effective treatments, and there is increasing evidence of a disconnect between traditional pathology and cognitive abilities with advancing age, indicative of individual variation in resilience to pathology. Here, we generated a comprehensive neuropathological, molecular, and transcriptomic characterization of hippocampus and two regions cortex in 107 aged donors (median = 90) from the Adult Changes in Thought (ACT) study as a freely-available resource (http://aging.brain-map.org/). We confirm established associations between AD pathology and dementia, albeit with increased, presumably aging-related variability, and identify sets of co-expressed genes correlated with pathological tau and inflammation markers. Finally, we demonstrate a relationship between dementia and RNA quality, and find common gene signatures, highlighting the importance of properly controlling for RNA quality when studying dementia.

Application of N-of-1 Experiments to Test the Efficacy of Inactivity Alert Features in Fitness Trackers to Increase Breaks from Sitting in Older Adults

BACKGROUND

Frequent breaks from sitting could improve health. Many commercially available fitness trackers deliver vibration alerts that could be used to cue sitting breaks. As a potentially pragmatic approach to promote frequent breaks from sitting, we tested the efficacy of inactivity alerts among obese older adults, a highly sedentary population.

METHODS

We conducted 10 sequential N-of-1 (single-case) experimental ABA trials. Participants (mean age = 68, mean BMI = 35) were monitored for a baseline phase ("A1") followed by an intervention phase ("B"). The intervention was then removed and participants were monitored to test an experimental effect (reversal "A2" phase). Total time in the study was limited to 25 days. During the intervention phase ("B"), participants used fitness trackers to stand up or move every time they received an alert (every 15 or 20 minutes of inactivity). Participants wore activPAL devices to measure breaks from sitting each day. Randomization tests were used to determine whether the number of breaks was significantly higher during the "B" phase than the two "A" phases.

RESULTS

Breaks were higher by 7.2 breaks per day during the "B" phase compared to the mean of the "A" phases. Seven out of 10 participants had more sitting breaks during the intervention phase which subsequently decreased during the reversal "A2" phase (combined p-value < .05).

CONCLUSION

Inactivity alert features within commercially available devices are efficacious for promoting modest improvements in breaks from sitting among older adults with obesity and could be a simple health-promoting strategy in this population.

Participant views on consent in cancer genetics research: preparing for the precision medicine era

The Precision Medicine Initiative (PMI) has created considerable discussions about research participant issues including re-consent and how and when to incorporate the patient experience into clinical trials. Within the changing landscape of genetic and genomic research, the preferences of participants are lacking yet are needed to inform policy. With the growing use of biobanks intended to support studies, including the national research cohort proposed under the PMI, understanding participant preferences, including re-consent, is a pressing concern. The Participant Issues Project (PIP) addresses this gap, and here we present data on participant attitudes regarding re-consent and broad consent in research studies. PIP study participants came from the Northwest Cancer Genetics Registry and included cancer patients, relatives, and controls. Thirty telephone interviews were conducted and analyzed using content and thematic analysis. Results indicate that in some scenarios, re-consent is needed. Most participants agreed that re-consent was necessary when the study direction changed significantly or a child participant became an adult, but not if the genetic variant changed. Most participants' willingness to participate in research would not be affected if the researcher or institution profited or if a broad consent form were used. Participants emphasized re-consent to provide information and control of the use of their data, now relevant for tailored treatment, while also prioritizing research as important. In the era of precision medicine, it is essential that policy makers consider participant preferences with regard to use of their materials and that participants understand genetic and genomic research and its harms and benefits as well as what broad consent entails, including privacy and re-identification risks.

The Feasibility of Reducing Sitting Time in Overweight and Obese Older Adults

BACKGROUND

Overweight and obese older adults have high sedentary time. We tested the feasibility and preliminary effects of a sedentary time reduction intervention among adults over age 60 with a body mass index over 27 kg/m2 using a nonrandomized one-arm design.

METHODS

Participants (N = 25, mean age = 71.4, mean body mass index = 34) completed an 8-week theory-based intervention targeting reduced total sitting time and increased sit-to-stand transitions. An inclinometer (activPAL) measured the primary outcomes, change in total sitting time and sit-to-stand transitions. Secondary outcomes included physical activity (ActiGraph GT3X+ accelerometer), self-reported sedentary behaviors, physical function (Short Physical Performance Battery), depressive symptoms (8-item Patient Health Questionnaire), quality of life (PROMIS), and study satisfaction. Paired t tests examined pre-post test changes in sitting time, sit-to-stand transitions, and secondary outcomes.

RESULTS

Inclinometer measured sitting time decreased by 27 min/day (p < .05) and sit-to-stand transitions increased by 2 per day (p > .05), while standing time increased by 25 min/day (p < .05). Accelerometer measured sedentary time, light-intensity, and moderate-to-vigorous physical activity improved (all p values ≤ .05). Self-reported sitting time, gait speed, and depressive symptoms also improved (all p values < .05). Effect sizes were small. Study satisfaction was high.

CONCLUSIONS

Reducing sitting time is feasible, and the intervention shows preliminary evidence of effectiveness among older adults with overweight and obesity. Randomized trials of sedentary behavior reduction in overweight and obese older adults, most of whom have multiple chronic conditions, may be promising.

Motivators and Barriers to Reducing Sedentary Behavior Among Overweight and Obese Older Adults

Purpose of the Study:

To explore individual, social, environmental, and program-related motivators, barriers, and impacts of sedentary behavior (SB) reduction among a group of overweight and obese older adults aged 60 and older.

Design and Methods:

Semistructured interviews were conducted with 24 participants following a SB reduction intervention. Transcripts from these interviews were iteratively coded by a team, and key themes were defined and refined guided by the social–ecological framework.

Results:

Motivators included the desire to improve health, newly acquired awareness of SB, the ease of incorporating SB reduction into current lifestyle, an adaptable environment, and the use of reminders. Barriers included existing health conditions, enjoyment of sedentary activities, unadaptable environments, fatigue, and difficulty understanding SB reduction as distinct from physical activity (PA). Participants reported impacts on physical and mental health and changes in awareness, exercise, and daily activity.

Implications:

Although in many ways motivators and barriers to reducing SB are similar to those of PA, SB interventions have special considerations and may ultimately be easier for some individuals to incorporate into their lifestyle.

A report on eight early-stage state and regional projects testing value-based payment

To help contain health care spending and improve the quality of care, practitioners and policy makers are trying to move away from fee-for-service toward value-based payment, which links providers' reimbursement to the value, rather than the volume, of services delivered. With funding from the Robert Wood Johnson Foundation, eight grantees across the country are designing and implementing value-based payment reform projects. For example, in Salem, Oregon, the Physicians Choice Foundation is testing "Program Oriented Payments," which include incentives for providers who follow a condition-specific program of care designed to meet goals set jointly by patient and provider. In this article we describe the funding rationale and the specific objectives, strategies, progress, and early stages of implementation of the eight projects. We also share some early lessons and identify prerequisites for success, such as ensuring that providers have broad and timely access to data so they can meet patients' needs in cost-effective ways.

Individual exposure to Simulium bites and intensity of Onchocerca volvulus infection

Background

Onchocerca volvulus, the causative agent of river blindness, is transmitted through the black fly Simulium damnosum s.l., which breeds in turbulent river waters. To date, the number of flies attacking humans has only been determined by standard fly collectors near the river or the village. In our study, we counted the actual number of attacking and successfully feeding S. damnosum s.l. flies landing on individual villagers during their routine day-time activities in two villages of the Sudan-savannah and rainforest of Cameroon. We compared these numbers to the number of flies caught by a standard vector-collector, one positioned near the particular villager during his/her daily activity and the other sitting at the nearest Simulium breeding site.

Results

Using these data obtained by the two vector-collectors, we were able to calculate the Actual Index of Exposure (AIE). While the AIE in the savannah was on average 6,3%, it was 34% in the rainforest. The Effective Annual Transmission Potential (EATP) for individual villagers was about 20 fold higher in the rainforest compared to the savannah.

Conclusions

Here we show for the first time that it is possible to determine the EATP. Further studies with more subjects are needed in the future. These data are important for the development of future treatment strategies.

Laser-assisted microdissection for the study of the ecology of parasites in their hosts

The population biology of internal parasites is difficult to study because the adult parasites are often inaccessible, deep within the host's body. Developing stages, such as eggs in the faeces or larvae in the skin are more easily obtained, but are difficult to handle because they are often very small and with a tough cuticle. This has limited their use in molecular ecology for estimating population biology parameters of the adults (their parents). We have used Onchocerca ochengi (a filarial nematode parasite of cattle) to describe a novel and generally applicable method of easily and conveniently isolating individual larvae (microfilariae) from the host using laser-assisted microdissection. Furthermore, we have been able to improve the isolation of DNA by using the laser to bisect the larva to release DNA from the tissues enclosed within the parasite cuticle, and in this way we have achieved amplification of fragments over 1400 bp, and routinely PCR-amplified single-copy sequences from 5% of the DNA from a single larva (the equivalent of approximately 15 nuclei), and regularly from 0.5%.

Psychological interventions to improve adherence to oral hygiene instructions in adults with periodontal diseases

BACKGROUND

Adherence to oral hygiene is an important aspect of the treatment of periodontal disease. Traditional educational interventions have been shown to be of little value in achieving long term behaviour change.

OBJECTIVES

The aim of this review was to determine the impact of interventions aimed to increase adherence to oral hygiene instructions in adult periodontal patients based on psychological models and theoretical frameworks. This review considered the following outcomes: Observational measures of oral health related behaviour Self reported oral health related behaviours, beliefs and attitudes towards oral health related behaviour Clinical markers of periodontal disease.

SEARCH STRATEGY

The Cochrane Oral Health Group's Trials Register (2005), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2004, Issue 4), MEDLINE (from 1966 to December 2004), EMBASE (from 1980 to December 2004), PSYCHINFO (from 1966 to December 2004), Ingenta (from 1998 to December 2004) and CINAHL (from 1966 to December 2004). Reference lists from relevant articles were searched and the authors of eligible trials were contacted to identify trials and obtain additional information. No language restriction was applied.

SELECTION CRITERIA

Randomised controlled trials testing the effectiveness of interventions based on psychological models compared with educational, attention or no active intervention controls to improve adherence to oral hygiene in adults with either gingivitis or periodontitis.

DATA COLLECTION AND ANALYSIS

Titles and abstracts of studies that were potentially relevant to the review were independently screened by two review authors. Those that were clearly ineligible were rejected. For the remaining studies, the full paper was reviewed by two review authors and where necessary further information was sought from the author to verify eligibility. Included studies were assessed on their quality using standard criteria.

MAIN RESULTS

The review identified four studies (including 344 participants) in which a psychological model or theory had been explicitly used as the basis for the design of the intervention. The overall quality of trials was low. Due to the hetereogeneity between studies, both in terms of outcome measures and psychological models adopted, a meta-analysis was not possible. The four studies adopted four different theoretical frameworks, though there was some overlap in that three of the studies incorporated elements of Operant and Classical Conditioning. Psychological interventions resulted in improved plaque scores in comparison to no intervention groups, and in one study in comparison to an attention control group. One study found decreased gingival bleeding in the active intervention group but no change in pocket depth or attachment loss after 4 months. Psychological interventions were associated with improved self reported brushing and flossing in both studies which assessed these behaviours. Only one study explored the impact of psychological interventions on beliefs and attitudes, the psychological intervention, in comparison to educational and no intervention controls, showed improved self efficacy beliefs in relation to flossing, but no effect on dental knowledge or self efficacy beliefs in relation to tooth brushing.

AUTHORS' CONCLUSIONS

There is tentative evidence from low quality studies that psychological approaches to behaviour management can improve oral hygiene related behaviours. However, the overall quality of the included trials was low. Furthermore, the design of the interventions was weak and limited, ignoring key aspects of the theories. Thus, there is a need for greater methodological rigour in the design of trials in this area.

Successful vaccination against Onchocerca ochengi infestation in cattle using live Onchocerca volvulus infective larvae

Epidemiological evidence has led to the hypothesis that the concurrent and predominant transmission of Onchocerca ochengi by Simulium damnosum s.l. in sub-Saharan Africa could lead to the protection of humans against onchocerciasis caused by Onchocerca volvulus (zooprophylaxis). To gain support for this hypothesis, we investigated whether exposure to O. volvulus could protect cattle from O. ochengi. Gudali calves were vaccinated with live O. volvulus-infective larvae and subsequently challenged with O. ochengi-infective larvae whilst raised in a fly-proof house. Post-challenge adult parasite and microfilaria development, IgG1 and lgG2 subclass antibodies response to Ov10/Ov11 recombinant Onchocerca antigens, and peripheral blood lymphocyte proliferative responses to O. ochengi crude antigens were studied over a 1-year period. The vaccinated-challenged animals had 83-87% less adult O. ochengi parasites than non-vaccinated-challenged animals. IgG1 and lgG2 antibodies to Ov10/Ov11 recombinant Onchocerca antigens were invoked by non-vaccinated-challenged animals but not by most (80%) of the vaccinated-challenged animals. These findings support the idea of cross-protection (zooprophylaxis) due to inoculation of humans with O. ochengi-infective larvae under natural transmission conditions in endemic areas.

Onchocerca ochengi acquisition in zebu Gudali cattle exposed to natural transmission: parasite population dynamics and IgG antibody subclass responses to Ov10/Ov11 recombinant antigens

Ngaoundere Gudali zebu cattle naturally exposed to Simulium damnosum s.l. and Culicoides spp. bites were examined during 4 years for O. ochengi adult worm acquisition, Onchocerca ochengi and Onchocerca gutturosa skin microfilaria dynamics, and IgG1 and IgG2 antibody subclass responses. Eleven animals acquired a total of 465 O. ochengi nodules (average of 17 per female and 72 per male). The O. ochengi nodule load was highly variable in individual animals and exacerbated in mature male cattle. Three patterns of acquisition of O. ochengi (resistant to new infestation, early susceptibility and late susceptibility), not associated with Simulium biting intensity (P > 0.05), were distinguished. The minimum prepatent periods for O. ochengi nodules, O. ochengi microfilariae and O. gutturosa microfilariae were 10, 20 and 21 months, respectively. The O. ochengi microfilaria density significantly (P < 0.001) increased with age, was higher in young mature bulls than female animals (P < 0.001) and finally reached highest levels (P < 0.005) during the dry season. Antibody responses to Ov10/Ov11 recombinant O. volvulus antigens were predominantly of the IgG1 subclass. High levels of this subclass (not IgG2) observed in new born calves declined to almost zero levels at the age of 5-8 months but IgG1 levels significantly increased (P < 0.05) with age subsequently during patency. Put together the acquisition and accumulation of O. ochengi parasites in zebu cattle, apart from being season, sex (gender) and host age associated, may also suggest a density-dependent regulation of parasite establishment in a proportion of the exposed population.

Human mature red blood cells express caspase-3 and caspase-8, but are devoid of mitochondrial regulators of apoptosis

Although proteases of the caspase family are essential mediators of apoptosis in nucleated cells, in anucleate cells their presence and potential functions are almost completely unknown. Human erythrocytes are a major cell population that does not contain a cell nucleus or other organelles. However, during senescence they undergo certain morphological alterations resembling apoptosis. In the present study, we found that mature erythrocytes contain considerable amounts of caspase-3 and -8, whereas essential components of the mitochondrial apoptotic cascade such as caspase-9, Apaf-1 and cytochrome c were missing. Strikingly, although caspases of erythrocytes were functionally active in vitro, they failed to become activated in intact erythrocytes either during prolonged storage or in response to various proapoptotic stimuli. Following an increase of cytosolic calcium, instead the cysteine protease calpain but not caspases became activated and mediated fodrin cleavage and other morphological alterations such as cell shrinkage. Our results therefore suggest that erythrocytes do not have a functional death system. In addition, because of the presence of procaspases and the absence of a cell nucleus and mitochondria erythrocytes may be an attractive system to dissect the role of certain apoptosis-regulatory pathways.

Multiple kinetics of mitochondrial cytochrome c release in drug-induced apoptosis

We investigated cytochrome c release kinetics in response to three apoptosis-inducing agents (tumor necrosis factor-alpha, staurosporine, and valinomycin) in MCF-7/Casp-3 cells stably transfected with enhanced green fluorescent protein (EGFP)-tagged cytochrome c. All three agents induced significant caspase activation in the cultures determined by monitoring the cleavage of fluorigenic caspase substrates in extracts from drug-treated MCF-7/Casp-3 cells, albeit the valinomycin-induced activation was less pronounced. Time-lapse confocal microscopy showed that tumor necrosis factor-alpha and staurosporine caused rapid, one- or multiple-step release of cytochrome c-EGFP from mitochondria. In contrast, valinomycin-induced cytochrome c-EGFP release occurred slowly over several hours. Unlike staurosporine, the valinomycin-induced cytochrome c release was not associated with translocation of the proapoptotic Bax protein to the mitochondria, and was not accompanied by co-release of the proapoptotic Smac protein. Immunoprecipitation experiments revealed that cytochrome c was also released out of the cell into the extracellular space before loss of plasma membrane integrity. Our data indicate the existence of multiple kinetics of cytochrome c release in drug-induced apoptosis.

Combined benefits of annual mass treatment with ivermectin and cattle zooprophylaxis on the severity of human onchocerciasis in northern Cameroon

We studied the effect of 10 annual distributions of ivermectin for control of human onchocerciasis on the reduction of Onchocerca volvulus transmission by Simulium vector flies. Prevalence and infection load in the human population decreased, whilst the annual biting rates (ABR) of the vector remained unchanged. The annual transmission potential of infective larvae of O. volvulus fell to 40% of the pre-intervention level, but was still sufficient to maintain endemicity. However, recent immigration of herds of nomadic cattle into the study area has diverted the flies from man to cattle, creating an additional zooprophylactic effect. The predominant transmission of the bovine filaria O. ochengi to man also provides some concomitant cross-protective immunity against further infestations with O. volvulus. The effects of ivermectin on O. volvulus, combined with the zooprophylactic effects of the increased cattle population, have produced a complex beneficial influence on the transmission of human onchocerciasis.

Rapid extracellular release of cytochrome c is specific for apoptosis and marks cell death in vivo

Diverse death stimuli including anticancer drugs trigger apoptosis by inducing the translocation of cytochrome c from the outer mitochondrial compartment into the cytosol. Once released, cytochrome c cooperates with apoptotic protease-activating factor-1 and deoxyadenosine triphosphate in caspase-9 activation and initiation of the apoptotic protease cascade. The results of this study show that on death induction by chemotherapeutic drugs, staurosporine and triggering of the death receptor CD95, cytochrome c not only translocates into the cytosol, but furthermore can be abundantly detected in the extracellular medium. The cytochrome c release from the cell is a rapid and apoptosis-specific process that occurred within 1 hour after induction of apoptosis, but not during necrosis. Interestingly, elevated cytochrome c levels were observed in sera from patients with hematologic malignancies. In the course of cancer chemotherapy, the serum levels of cytochrome c in the majority of the patients grew rapidly as a result of increased cell death. These data suggest that monitoring of cytochrome c in the serum of patients with tumors might serve as a useful clinical marker for the detection of the onset of apoptosis and cell turnover in vivo.

Activation of spinach pullulanase by reduction results in a decrease in the number of isomeric forms

Spinach starch debranching enzyme, a limit dextrinase or pullulanase (EC 3.2.1.41), is a monomeric protein of 100 kDa that produces up to seven coexisting and mutually interconvertible isomers of different specific activity, a phenomenon that has been termed microheterogeneity and for which a structural explanation has not yet been presented. The enzyme can be activated by reduction, in particular by thiol reagents, and inactivated by oxidation and the concomitant change of the patterns of its isomeric forms could be quantified by chromatofocusing. The hypothesis was examined that reduction of the enzyme's thiol groups shifts the isomer pattern towards the forms with a higher specific activity while oxidation favours the less active forms. Using TCEP as reductant only the form with the highest specific activity was obtained. This form was almost inaccessible for proteolysis by trypsin while the oxidized and GSH-activated enzyme yielded four peptides when treated with trypsin. Their sequence indicated cleavage predominantly of loops connecting the beta-strands and alpha-helices of the (beta/alpha)(8)-barrel which forms the catalytic site of the pullulanase. Formation of various disulphide bridges between the loops connecting the barrel structures -- predominantly on one side -- may be the reason for the microheterogeneity of the spinach pullulanase. In vivo, the enzyme maintains its activated state due to the high concentration of GSH in the chloroplast. However, the chloroplast's pH shifts from day (pH 8) to night (pH 7) and thus could also alter the activity of the protein in accordance with the required function in starch metabolism.

Onchocerca ochengi transmission dynamics and the correlation of O. ochengi microfilaria density in cattle with the transmission potential

The intensity of natural transmission of Onchocerca ochengi and Onchocerco volvulus by anthropo-boophilic Simulium damnosum s.l. was studied longitudinally in two cattle watering sites of a cattle ranch within a predominantly cattle populated area of the Guinea savanna of Cameroon and related to cattle O. ochengi skin microfilaria abundance. During the 12 months study period, a total of 4696 flies was individually dissected to examine the monthly transmission potential (MTP) of O. ochengi and O. volvulus. The estimated Simulium damnosum s.l. annual biting rates (ABR) on human baits were 47529 flies at the bank of the Vina "du sud" river. The ABR at the lake, which was situated at about 2 km upland from the perennial river, was 8579. The monthly parous rate was highly correlated with monthly biting rate. The annual transmission potentials (ATP) of O. ochengi were calculated to be 7732 and 1669 at the riverbank and the lake, respectively. Transmission occurred mainly in the dry season, peaking in the months of January to mid-March when dermal microfilaria density in the animals was also the highest. The O. ochengi microfilaria uptake by the fly vectors was host microfilaria density-dependent. The MTP of O. ochengi was positively correlated with dermal microfilaria density. The mean number of microfilariae per fly taken up during a blood meal was high during the dry season as was the mean number of infective larvae per fly but declined significantly with the onset of the early rains. A similar seasonality of transmission was also observed for O. volvulus that was concurrently transmitted by the same vector flies, but its ATP was comparatively much lower: 1332 infective larvae per man per year at the riverbank and 107 around the lake. The population dynamics of cattle microfilariae therefore plays an important role in the regulation of O. ochengi transmission.

Lipopolysaccharide-like molecules derived from Wolbachia endobacteria of the filaria Onchocerca volvulus are candidate mediators in the sequence of inflammatory and antiinflammatory responses of human monocytes

The majority of Onchocerca volvulus-infected persons show signs of cellular anergy, and long-time survival of adult and larval parasites in subcutaneous tissue is observed. The mechanisms leading to immunological hyporesponsiveness are poorly understood. Monocytes/macrophages represent a link between the innate and acquired immune system and are candidate cells to promote inflammatory and antiinflammatory processes. In the present study we have shown that products of microfilarial (O. volvulus) and adult (O. volvulus and O. ochengi) parasites affect monocytes in vitro. An early production of TNF-alpha by exposed monocytes was followed by the production of IL-10 and a reduced expression of HLA-DR and the costimulatory molecules B7-1 and B7-2, while other adhesion receptors remained unaffected. Downregulation of the functional membrane receptors failed to occur after treatment of the cells with anti-IL-10 antibodies. The engagement of CD14, a dominant membrane receptor on monocytes and major binding protein for lipopolysaccharides, was indicated by partial blocking of monocyte modulation by neutralizing antibodies to CD14 and by the antagonistic lipid A analog compound 406. Lipopolysaccharide-like molecules were detected in sterile products of O. volvulus stages which could originate from Wolbachia bacteria related to Gram-negative Rickettsiales, known to be abundant in the hypodermis and the female reproductive organs of O. volvulus. The present results indicate that the monocyte/macrophage may be a major target cell for immunomodulatory parasite-derived and intraparasitic, bacteria-derived molecules, thereby contributing to the host's cellular hyporesponsiveness.

Onchocerca ochengi infections in cattle as a model for human onchocerciasis: recent developments

The bovine parasite Onchocerca ochengi is a nodule-dwelling filarial nematode, closely related to O. volvulus, the causal agent of human River Blindness, and, sharing with it, the same vector. This brief review, based on a presentation at the BSP Autumn Symposium 1999, describes recent work supported by the WHO Drug Development Research Macrofil programme and the Edna McConnell Clark Foundation vaccine development programme, to research the chemotherapy and immunology of onchocerciasis utilising this model system, with experimental infections in Liverpool and field infections in northern Cameroon. In a series of chemotherapeutic trials involving 10 compounds in 20 treatment regimes, the comparability of drug efficacy against O. ochengi with that described against O. volvulus has been demonstrated. Repeated, long-term treatment with oxytetracycline has been shown to be macrofilaricidal and the effect is hypothesized to be related to action on Wolbachia endobacteria, abundant in O. ochengi. Avermectins/milbemycins are not macrofilaricidal (even in high and repeated long-term treatments) but induce sustained abrogation of embryogenesis. In prospective, field exposure experiments with naive calves, prophylactic treatments with ivermectin and moxidectin prevented the development of adult worm infection, raising the possibility that drug-attenuated larval challenge infections may induce immunity. Putatively immune adult cattle exist in endemically exposed populations, and these have been shown to be significantly less susceptible to challenge than age-matched naive controls, whereas radically drug-cured, previously patently-infected cattle were not. Experimental infections with O. ochengi have revealed the kinetics of the immune response in relation to parasite development and demonstrate analogous responses to those reported in O. volvulus infection in humans and chimpanzees. In an immunization experiment with irradiated L3 larvae, cattle were significantly protected against experimental challenge--the first such demonstration of the experimental induction of immunity in a natural Onchocerca host-parasite system. Taken collectively, these studies not only demonstrate the similarity between the host-parasite relationships of O. ochengi in cattle and O. volvulus in humans, but promise to advance options for the control of human onchocerciasis.

Antisense inhibition of plastidial phosphoglucomutase provides compelling evidence that potato tuber amyloplasts import carbon from the cytosol in the form of glucose-6-phosphate

The aim of this work was to establish whether plastidial phosphoglucomutase is involved in the starch biosynthetic pathway of potato tubers and thereby to determine the form in which carbon is imported into the potato amyloplast. For this purpose, we cloned the plastidial isoform of potato PGM (StpPGM), and using an antisense approach generated transgenic potato plants that exhibited decreased expression of the StpPGM gene and contained significantly reduced total phosphoglucomutase activity. We confirmed that this loss in activity was due specifically to a reduction in plastidial PGM activity. Potato lines with decreased activities of plastidial PGM exhibited no major changes in either whole-plant or tuber morphology. However, tubers from these lines exhibited a dramatic (up to 40%) decrease in the accumulation of starch, and significant increases in the levels of sucrose and hexose phosphates. As tubers from these lines exhibited no changes in the maximal catalytic activities of other key enzymes of carbohydrate metabolism, we conclude that plastidial PGM forms part of the starch biosynthetic pathway of the potato tuber, and that glucose-6-phosphate is the major precursor taken up by amyloplasts in order to support starch synthesis.

Macrofilaricidal activity of tetracycline against the filarial nematode Onchocerca ochengi: elimination of Wolbachia precedes worm death and suggests a dependent relationship

Filarial nematodes are important and widespread parasites of animals and humans. We have been using the African bovine parasite Onchocerca ochengi as a chemotherapeutic model for O. volvulus, the causal organism of 'river blindness' in humans, for which there is no safe and effective drug lethal to adult worms. Here we report that the antibiotic, oxytetracycline is macrofilaricidal against O. ochengi. In a controlled trial in Cameroon, all adult worms (as well as microfilariae) were killed, and O. ochengi intradermal nodules resolved, by nine months' post-treatment in cattle treated intermittently for six months. Adult worms removed from concurrent controls remained fully viable and reproductively active. By serial electron-microscopic examination, the macrofilaricidal effects were related to the elimination of intracellular micro-organisms, initially abundant. Analysis of a fragment of the 16S rRNA gene from the O. ochengi micro-organisms confirmed them to be Wolbachia organisms of the order Rickettsiales, and showed that the sequence differed in only one nucleotide in 858 from the homologous sequence of the Wolbachia organisms of O. volvulus. These data are, to our knowledge, the first to show that antibiotic therapy can be lethal to adult filariae. They suggest that tetracycline therapy is likely to be macrofilaricidal against O. volvulus infections in humans and, since similar Wolbachia organisms occur in a number of other filarial nematodes, against those infections too. In that the elimination of Wolbachia preceded the resolution of the filarial infections, they suggest that in O. ochengi at least, the Wolbachia organisms play an essential role in the biology and metabolism of the filarial worm.

Isolation and characterization of a calendic acid producing (8,11)-linoleoyl desaturase

For the biosynthesis of calendic acid a (8,11)-linoleoyl desaturase activity has been proposed. To isolate this desaturase, PCR-based cloning was used. The open reading frame of the isolated full-length cDNA is a 1131 bp sequence encoding a protein of 377 amino acids. For functional identification the cDNA was expressed in Saccharomyces cerevisiae, and formation of calendic acid was analyzed by RP-HPLC. The expression of the heterologous enzyme resulted in a significant amount of calendic acid presumably esterified within phospholipids. The results presented here identify a gene encoding a new type of (1,4)-acyl lipid desaturase.

Antisense repression of hexokinase 1 leads to an overaccumulation of starch in leaves of transgenic potato plants but not to significant changes in tuber carbohydrate metabolism

Potato (Solanum tuberosum L.) plants transformed with sense and antisense constructs of a cDNA encoding the potato hexokinase 1 (StHK1) exhibited altered enzyme activities and expression of StHK1 mRNA. Measurements of the maximum catalytic activity of hexokinase revealed a 22-fold variation in leaves (from 22% of the wild-type activity in antisense transformants to 485% activity in sense transformants) and a 7-fold variation in developing tubers (from 32% of the wild-type activity in antisense transformants to 222% activity in sense transformants). Despite the wide range of hexokinase activities, no change was found in the fresh weight yield, starch, sugar, or metabolite levels of transgenic tubers. However, there was a 3-fold increase in the starch content of leaves from the antisense transformants after the dark period. Starch accumulation at the end of the night period was correlated with a 2-fold increase of glucose and a decrease of sucrose content. These results provide strong support for the hypothesis that glucose is a primary product of transitory starch degradation and is the sugar that is exported to the cytosol at night to support sucrose biosynthesis.

Chemoprophylaxis of Onchocerca infections: in a controlled, prospective study ivermectin prevents calves becoming infected with O. ochengi

Onchocerciasis ('River Blindness'), caused by the filarial nematode Onchocerca volvulus is of major public health importance in West Africa. Ivermectin, a drug originally developed for veterinary use, is now being incorporated in control strategies but whilst it has potent efficacy against L1 larvae (microfilariae), ivermectin is not lethal to adult (L5) O. volvulus, nor to adults of the related cattle parasite O. ochengi. We have exploited this model to determine if ivermectin has prophylactic activity against naturally transmitted, O. ochengi infections in a controlled, prospective study in northern Cameroon. Calves were treated monthly with ivermectin at either 200 micrograms/kg or 500 micrograms/kg for 21 months. None of 15 treated calves developed adult worm infection, whereas 5/6 untreated controls became infected (P < 0.001) with a total of 54 O. ochengi nodules, and all 5 developed patent microfilaridermia. These results have significant implications for the use of ivermectin in humans, and suggest that strategic chemotherapy at times of maximal transmission will confer prophylactic as well as therapeutic benefits.

In-vitro uptake of ivermectin by adult male Onchocerca ochengi

Ivermectin is not lethal to the adult worms of Onchocerca volvulus or to those of O. ochengi, a cattle parasite closely related to O. volvulus. Although ivermectin penetrates the nodules in which the adults of these nematodes live, it is not known what levels of the drug enter the worms. Adult male O. ochengi were incubated in [3H]ivermectin in a saturated solution of unlabelled ivermectin (11.44 microM), to measure uptake by the oral and transcuticular routes, and in [3H]inulin, to ascertain if oral ingestion occurs in vitro. Uptake of [3H]ivermectin was high [1040 disintegrations/min (d.p.m.) at 3 h, representing a mean total of 86 pmoles ivermectin/worm] and occurred predominantly by the transcuticular route. Viability of worms was not reduced by this exposure, and uptake continued for up to 12 h. Only low levels of [3H]inulin (four d.p.m.) were detected in worms, indicating that the gut is probably not functional in vitro. Scanning and transmission electron microscopy revealed that the epicuticle of both sexes had an irregular surface which was pitted with a honeycomb structure in males, and rough and abundantly folded in females. These structures greatly increased the absorptive surface of the worms. In conclusion, ivermectin is able to enter adult O. ochengi males at concentrations sufficient to kill non-filarial nematodes.

Protein heterogeneity of spinach pullulanase results from the coexistence of interconvertible isomeric forms of the monomeric enzyme

Purified pullulanase (starch-debranching enzyme, R-enzyme, EC 3.2.1. 41) from spinach (Spinacia oleracea L.) chloroplasts separated into at least seven individual enzymically active proteins (isomers, numbered 1-7) on isoelectric focusing or column chromatofocusing. At their isoelectric points (between pH 4.7 and 5.2) these forms were rather stable. At slightly alkaline pH, each converted into the whole set of isomers. PAGE of the purified enzyme under denaturing or non-denaturing conditions resulted in one protein band. When substrate (amylopectin or pullulan) was included in the gel, the native enzyme as well as any of the individual isomers separated into two (sometimes three) bands ('substrate-induced forms', numbered I-III) with different specific activities, dissociation constants of the enzyme-substrate complexes and activation energies. Each substrate-induced form produced the whole set of seven isomers on isoelectric focusing. The specific activity of the total enzyme reflected the relative proportions of the substrate-induced forms. To some extent the relative proportions, as determined by crossed immunoelectrophoresis, could be shifted in favour of the more or the less active forms by reduction with dithiothreitol, and gentle oxidation respectively. Activation by dithiothreitol did not alter the mode of action of the enzyme but only increased the velocity of substrate degradation and extended its activity into the pH range of the chloroplast. As a consequence of isomer interconversion, microheterogeneity could serve to regulate pullulanase activity in a biochemical manner that shares some features with allosteric regulation.

cDNA sequence and heterologous expression of monomeric spinach pullulanase: multiple isomeric forms arise from the same polypeptide

The spinach pullulanase gene was cloned and sequenced using peptide sequences of the purified enzyme as a starting point and employing PCR techniques and cDNA library screening. Its open reading frame codes for a protein of 964 amino acids which represents a precursor of the pullulanase. The N-terminal transit peptide consists of 65 amino acids, and the mature protein, comprising 899 amino acids, has a calculated molecular mass of 99kDa. Pullulanase is a member of the alpha-amylase family. In addition to a characteristic catalytic (beta/alpha)8-barrel domain, it contains a domain, F, that is specific for branching and debranching enzymes. Pullulanase cDNA was expressed in Escherichia coli, and the purified protein was compared with the enzyme from spinach leaves. Identity of the two proteins was confirmed in terms of catalytic properties, N-terminal amino acid sequences and molecular masses. The pullulanase produced by E. coli showed the same microheterogeneity as the spinach leaf enzyme: it could be resolved into two substrate-induced forms by electrophoresis in amylopectin-containing polyacrylamide gels, and, in the absence of substrate, into several free forms (charge isomers) by isoelectric focusing or chromatofocusing. Rechromatofocusing of single free forms resulted in the originally observed pattern of molecular forms. However, heterogeneity of the protein disappeared on isoelectric focusing under completely denaturing conditions when only one protein band was observed. Post-translational modifications such as glycosylation and phosphorylation could be excluded as potential explanations for the protein heterogeneity. Therefore the microheterogeneity of spinach leaf pullulanase results from neither genetic variation nor post-translational modifications, but is a property of the single unmodified gene product. The different interconvertible forms of the pullulanase represent protein populations of different tertiary structure of the same polypeptide.

Onchocerca ochengi: epidemiological evidence of cross-protection against Onchocerca volvulus in man

In North Cameroon, the vector of Onchocerca volvulus (causative agent of human onchocerciasis) also transmits 2 filariae of animals: O. ochengi from cattle and O. ramachandrini from wart hogs. In order to assess the qualitative and quantitative roles of these 'animal filariae' in the epidemiology of O. volvulus, the transmission of the 3 parasites was measured in 2 villages and related to the endemicity of human onchocerciasis. In Galim, a cattle-farming Guinea savanna village where wild animals are rare, the overwhelming majority of all filarial infections found in the Simulium damnosum s.l. vectors throughout the year were O. ochengi (89%). The remaining infections were mainly O. volvulus (10.5%), and a few O. ramachandrini (0.5%). In Karna, a crop-farming Sudan savanna village where cattle are rare, but wild animals common, flies were also more frequently infected with animal filariae than with the human parasite. In the dry season, when nomadic cattle are present, 54% of all infections were O. ochengi, 36% O. volvulus and 10% O. ramachindrini. In the rainy season, when the cattle move away, flies were mainly infected with O. ramachandrini (52% of all infections) and secondly with O. volvulus (48%). In Karna, the relationship between the Annual Transmission Potential (ATP) of O. volvulus and its prevalence in the human population conformed to other onchocerciasis foci, in that a moderate ATP led to hyperendemic onchocerciasis. In Galim, however, a 7-fold higher O. volvulus-ATP (caused by a very high biting rate of the flies) contrasted with a strikingly low endemicity of onchocerciasis. Since, at the same time, in Galim the transmission of O. ochengi (measured on man) was very high (15,000 L3/fly collector/year), we hypothesize that the reduced endemicity of onchocerciasis in Galim is due to 'natural heterologous vaccination' by the large annual number of O. ochengi-L3, inoculated into man by anthropo-boophilic S. damnosum s.l. The importance of micro-epidemiology for the understanding of the interlinkage of human and animal onchocerciasis is discussed.