Host-mediated selection impacts the diversity of Plasmodium falciparum antigens within infections

Host immunity exerts strong selective pressure on pathogens. Population-level genetic analysis can identify signatures of this selection, but these signatures reflect the net selective effect of all hosts and vectors in a population. In contrast, analysis of pathogen diversity within hosts provides information on individual, host-specific selection pressures. Here, we combine these complementary approaches in an analysis of the malaria parasite Plasmodium falciparum using haplotype sequences from thousands of natural infections in sub-Saharan Africa. We find that parasite genotypes show preferential clustering within multi-strain infections in young children, and identify individual amino acid positions that may contribute to strain-specific immunity. Our results demonstrate that natural host defenses to P. falciparum act in an allele-specific manner to block specific parasite haplotypes from establishing blood-stage infections. This selection partially explains the extreme amino acid diversity of many parasite antigens and suggests that vaccines targeting such proteins should account for allele-specific immunity.

Host immune responses exert selective pressure on Plasmodium falciparum. Here, the authors show that allele-specific immunity impacts the antigenic diversity of individual malaria infections. This process partially explains the extreme amino acid diversity of many parasite antigens and suggests that vaccines should account for allele-specific immunity.

Infant and child mortality in relation to malaria transmission in KEMRI/CDC HDSS, Western Kenya: validation of verbal autopsy

Background

Malaria transmission reduction is a goal of many malaria control programmes. Little is known of how much mortality can be reduced by specific reductions in transmission. Verbal autopsy (VA) is widely used for estimating malaria specific mortality rates, but does not reliably distinguish malaria from other febrile illnesses. Overall malaria attributable mortality includes both direct and indirect deaths. It is unclear what proportion of the deaths averted by reducing malaria transmission are classified as malaria in VA.

Methods

Both all-cause, and cause-specific mortality reported by VA for children under 5 years of age, were assembled from the KEMRI/CDC health and demographic surveillance system in Siaya county, rural Western Kenya for the years 2002–2004. These were linked to household-specific estimates of the Plasmodium falciparum entomological inoculation rate (EIR) based on high resolution spatio-temporal geostatistical modelling of entomological data. All-cause and malaria specific mortality (by VA), were analysed in relation to EIR, insecticide-treated net use (ITN), socioeconomic status (SES) and parameters describing space–time correlation. Time at risk for each child was analysed using Bayesian geostatistical Cox proportional hazard models, with time-dependent covariates. The outputs were used to estimate the diagnostic performance of VA in measuring mortality that can be attributed to malaria exposure.

Results

The overall under-five mortality rate was 80 per 1000 person-years during the study period. Eighty-one percent of the total deaths were assigned causes of death by VA, with malaria assigned as the main cause of death except in the neonatal period. Although no trend was observed in malaria-specific mortality assessed by VA, ITN use was associated with reduced all-cause mortality in infants (hazard ratio 0.15, 95% CI 0.02, 0.63) and the EIR was strongly associated with both all-cause and malaria-specific mortality. 48.2% of the deaths could be attributed to malaria by analysing the exposure–response relationship, though only 20.5% of VAs assigned malaria as the cause and the sensitivity of VAs was estimated to be only 26%. Although VAs assigned some deaths to malaria even in areas where there was estimated to be no exposure, the specificity of the VAs was estimated to be 85%.

Conclusion

Interventions that reduce P. falciparum transmission intensity will not only significantly reduce malaria-diagnosed mortality, but also mortality assigned to other causes in under-5 year old children in endemic areas. In this setting, the VA tool based on clinician review substantially underestimates the number of deaths that could be averted by reducing malaria exposure in childhood, but has a reasonably high specificity. This suggests that malaria transmission-reducing interventions such as ITNs can potentially reduce overall child mortality by as much as twice the total direct malaria burden estimated from VAs.

Electronic supplementary material

The online version of this article (10.1186/s12936-018-2184-x) contains supplementary material, which is available to authorized users.

Using health and demographic surveillance system (HDSS) data to analyze geographical distribution of socio-economic status; an experience from KEMRI/CDC HDSS

Continuous monitoring in health and demographic surveillance sites (HDSS) allows for collection of longitudinal demographic data, health related, and socio-economic indicators of the site population. We sought to use household survey data collected between 2002 and 2006 in the Kenya Medical Research Institute in collaboration with Centers for Disease Control and prevention (KEMRI/CDC) HDSS site in Asembo and Gem Western Kenya to estimate socio-economic status (SES) and assess changes of SES over time and space. Data on household assets and characteristics, mainly source of drinking water, cooking fuel, and occupation of household head was annually collected from 44,313 unique households during the study period. An SES index was calculated as a weighted average of assets using weights generated via Principal Component Analysis (PCA), Polychoric PCA, and Multiple Correspondence Analysis (MCA) methods applied to the pooled data. The index from the best method was used to rank households into SES quintiles and assess their transition over time across SES categories. Kriging was employed to produce SES maps at the start and the end of the study period. First component of PCA, Polychoric PCA, and MCA accounted for 13.7%, 31.8%, and 47.3%, respectively of the total variance of all variables. The gap between the poorest and the least poor increased from 1% at the start to 6% at the end of the study period. Spatial analysis revealed that the increase in least poor households was centered in the lower part of study area (Asembo) over time. No significant changes were observed in Gem. The HDSS sites can provide a platform to assess spatial-temporal changes in the SES status of the population. Evidence on how SES varied over time and space within the same geographical area may provide a useful tool to design interventions in health and other areas that have a close bearing to the SES of the population.

Assessment of molecular markers for anti-malarial drug resistance after the introduction and scale-up of malaria control interventions in western Kenya

Background

Although it is well known that drug pressure selects for drug-resistant parasites, the role of transmission reduction by insecticide-treated bed nets (ITNs) on drug resistance remains unclear. In this study, the drug resistance profile of current and previous first-line anti-malarials in Kenya was assessed within the context of drug policy change and scale-up of ITNs. National first-line treatment changed from chloroquine (CQ) to sulphadoxine-pyrimethamine (SP) in 1998 and to artemether-lumefantrine (AL) in 2004. ITN use was scaled-up in the Asembo, Gem and Karemo areas of western Kenya in 1997, 1999 and 2006, respectively.

Methods

Smear-positive samples (N = 253) collected from a 2007 cross-sectional survey among children in Asembo, Gem and Karemo were genotyped for mutations in pfcrt and pfmdr1 (CQ), dhfr and dhps (SP), and at pfmdr-N86 and the gene copy number in pfmdr1 (lumefantrine). Results were compared among the three geographic areas in 2007 and to retrospective molecular data from children in Asembo in 2001.

Results

In 2007, 69 and 85% of samples harboured the pfmdr1-86Y mutation and dhfr/dhps quintuple mutant, respectively, with no significant differences by study area. However, the prevalence of the pfcrt-76T mutation differed significantly among areas (p <0.02), between 76 and 94%, with the highest prevalence in Asembo. Several 2007 samples carried mutations at dhfr-164L, dhps-436A, or dhps-613T. From 2001 to 2007, there were significant increases in the pfcrt-76T mutation from 82 to 94% (p <0.03), dhfr/dhps quintuple mutant from 62 to 82% (p <0.03), and an increase in the septuple CQ and SP combined mutant haplotype, K₇₆Y₈₆I₅₁R₅₉N₁₀₈G₄₃₇E₅₄₀, from 28 to 39%. The prevalence of the pfmdr1-86Y mutation remained unchanged. All samples were single copy for pfmdr1.

Conclusions

Molecular markers associated with lumefantrine resistance were not detected in 2007. More recent samples will be needed to detect any selective effects by AL. The prevalence of CQ and SP resistance markers increased from 2001 to 2007 in the absence of changes in transmission intensity. In 2007, only the prevalence of pfcrt-76T mutation differed among study areas of varying transmission intensity. Resistant parasites were most likely selected by sustained drug pressure from the continued use of CQ, SP, and mechanistically similar drugs, such as amodiaquine and cotrimoxazole. There was no clear evidence that differences in transmission intensity, as a result of ITN scale-up, influenced the prevalence of drug resistance molecular markers.

Electronic supplementary material

The online version of this article (doi:10.1186/s12936-015-0588-4) contains supplementary material, which is available to authorized users.

First TDCR measurements at low energies using a miniature x-ray tube

Developed for radionuclide standardization using liquid scintillation, the Triple to Double Coincidence Ratio (TDCR) method is applied using coincidence counting obtained with a specific three-photomultiplier system. For activity determination, a statistical model of light emission is classically used to establish a relation between the detection efficiency and the experimental TDCR value. At LNE-LNHB, a stochastic approach of the TDCR modeling was developed using the Monte Carlo code Geant4. The interest of this TDCR-Geant4 model is the possibility to simulate the propagation of optical photons from their creation in the scintillation vial to the production of photoelectrons in photomultipliers. As an alternative to the use of radionuclide sources, first TDCR measurements are presented using a miniature x-ray tube closely coupled to the scintillation vial. The objective of this new set-up was to enable low-energy depositions (lower than 20 keV) in liquid scintillator in order to study the influence of both time and geometrical dependence between PMTs already observed with radioactive sources. As for the statistical TDCR model, the non-linearity of light emission is implemented in the TDCR-Geant4 model using the Birks formula which depends on the kB factor and the scintillation yield. Measurements performed with the x-ray tube are extended to the assessment of these parameters and they are tested afterwards in the TDCR-Geant4 model for activity measurements of (3)H.

A pan-Canadian practice guideline and algorithm: screening, assessment, and supportive care of adults with cancer-related fatigue

PURPOSE

The purpose of the present systematic review was to develop a practice guideline to inform health care providers about screening, assessment, and effective management of cancer-related fatigue (crf) in adults.

METHODS

The internationally endorsed adapte methodology was used to develop a practice guideline for pan-Canadian use. A systematic search of the literature identified a broad range of evidence: clinical practice guidelines, systematic reviews, and other guidance documents on the screening, assessment, and management of crf. The search included medline, embase, cinahl, the Cochrane Library, and other guideline and data sources to December 2009.

RESULTS

Two clinical practice guidelines were identified for adaptation. Seven guidance documents and four systematic reviews also provided supplementary evidence to inform guideline recommendations. Health professionals across Canada provided expert feedback on the adapted recommendations in the practice guideline and algorithm through a participatory external review process.

CONCLUSIONS

Practice guidelines can facilitate the adoption of evidence-based assessment and interventions for adult cancer patients experiencing fatigue. Development of an algorithm to guide decision-making in practice may also foster the uptake of a guideline into routine care.

Mortality trends from 2003 to 2009 among adolescents and young adults in rural Western Kenya using a health and demographic surveillance system

BACKGROUND

Targeted global efforts to improve survival of young adults need information on mortality trends; contributions from health and demographic surveillance system (HDSS) are required.

METHODS AND FINDINGS

This study aimed to explore changing trends in deaths among adolescents (15-19 years) and young adults (20-24 years), using census and verbal autopsy data in rural western Kenya using a HDSS. Mid-year population estimates were used to generate all-cause mortality rates per 100,000 population by age and gender, by communicable (CD) and non-communicable disease (NCD) causes. Linear trends from 2003 to 2009 were examined. In 2003, all-cause mortality rates of adolescents and young adults were 403 and 1,613 per 100,000 population, respectively, among females; and 217 and 716 per 100,000, respectively, among males. CD mortality rates among females and males 15-24 years were 500 and 191 per 100,000 (relative risk [RR] 2.6; 95% confidence intervals [CI] 1.7-4.0; p<0.001). NCD mortality rates in same aged females and males were similar (141 and 128 per 100,000, respectively; p = 0.76). By 2009, young adult female all-cause mortality rates fell 53% (χ(2) for linear trend 30.4; p<0.001) and 61.5% among adolescent females (χ(2) for linear trend 11.9; p<0.001). No significant CD mortality reductions occurred among males or for NCD mortality in either gender. By 2009, all-cause, CD, and NCD mortality rates were not significantly different between males and females, and among males, injuries equalled HIV as the top cause of death.

CONCLUSIONS

This study found significant reductions in adolescent and young adult female mortality rates, evidencing the effects of targeted public health programmes, however, all-cause and CD mortality rates among females remain alarmingly high. These data underscore the need to strengthen programmes and target strategies to reach both males and females, and to promote NCD as well as CD initiatives to reduce the mortality burden amongst both gender.

Spatial and temporal dynamics of malaria transmission in rural Western Kenya

Background

Understanding the relationship between Plasmodium falciparum malaria transmission and health outcomes requires accurate estimates of exposure to infectious mosquitoes. However, measures of exposure such as mosquito density and entomological inoculation rate (EIR) are generally aggregated over large areas and time periods, biasing the outcome-exposure relationship. There are few studies examining the extent and drivers of local variation in malaria exposure in endemic areas.

Methods

We describe the spatio-temporal dynamics of malaria transmission intensity measured by mosquito density and EIR in the KEMRI/CDC health and demographic surveillance system using entomological data collected during 2002–2004. Geostatistical zero inflated binomial and negative binomial models were applied to obtain location specific (house) estimates of sporozoite rates and mosquito densities respectively. Model-based predictions were multiplied to estimate the spatial pattern of annual entomological inoculation rate, a measure of the number of infective bites a person receive per unit of time. The models included environmental and climatic predictors extracted from satellite data, harmonic seasonal trends and parameters describing space-time correlation.

Results

Anopheles gambiae s.l was the main vector species accounting for 86 % (n = 2309) of the total mosquitoes collected with the remainder being Anopheles funestus. Sixty eight percent (757/1110) of the surveyed houses had no mosquitoes. Distance to water bodies, vegetation and day temperature were strongly associated with mosquito density. Overall annual point estimates of EIR were 6.7, 9.3 and 9.6 infectious bites per annum for 2002, 2003 and 2004 respectively. Monthly mosquito density and EIR varied over the study period peaking in May during the wet season each year. The predicted and observed densities of mosquitoes and EIR showed a strong seasonal and spatial pattern over the study area.

Conclusions

Spatio-temporal maps of malaria transmission intensity obtained in this study are not only useful in understanding variability in malaria epidemiology over small areas but also provide a high resolution exposure surface that can be used to analyse the impact of transmission on malaria related and all-cause morbidity and mortality.

The influence of primary health care organizational models on patients’ experience of care in different chronic disease situations

Objectives

To examine the extent to which experience of care varies across chronic diseases, and to analyze the relationship of primary health care (PHC) organizational models with the experience of care reported by patients in different chronic disease situations.

Methods

We linked a population survey and a PHC organizational survey conducted in two regions of Quebec. We identified five groups of chronic diseases and contrasted these with a no–chronic-disease group.

Results

Accessibility of care is low for all chronic conditions and shows little variation across diseases. The contact and the coordination-integrated models are the most accessible, whereas the single-provider model is the least. Process and outcome indices of care experience are much higher than accessibility for all conditions and vary across diseases, with the highest being for cardiovascular-risk-factors and the lowest for respiratory diseases (for people aged 44 and under). However, as we move from risk factors to more severe chronic conditions, the coordination-integrated and community models are more likely to generate better process of care, highlighting the greater potential of these two models to meet the needs of more severely chronically ill individuals within the Canadian health care system.

The influence of primary health care organizational models on patients' experience of care in different chronic disease situations

OBJECTIVES

To examine the extent to which experience of care varies across chronic diseases, and to analyze the relationship of primary health care (PHC) organizational models with the experience of care reported by patients in different chronic disease situations.

METHODS

We linked a population survey and a PHC organizational survey conducted in two regions of Quebec. We identified five groups of chronic diseases and contrasted these with a no-chronic-disease group.

RESULTS

Accessibility of care is low for all chronic conditions and shows little variation across diseases. The contact and the coordination-integrated models are the most accessible, whereas the single-provider model is the least. Process and outcome indices of care experience are much higher than accessibility for all conditions and vary across diseases, with the highest being for cardiovascular-risk-factors and the lowest for respiratory diseases (for people aged 44 and under). However, as we move from risk factors to more severe chronic conditions, the coordination-integrated and community models are more likely to generate better process of care, highlighting the greater potential of these two models to meet the needs of more severely chronically ill individuals within the Canadian health care system.

Associations between peripheral Plasmodium falciparum malaria parasitemia, human immunodeficiency virus, and concurrent helminthic infection among pregnant women in Malawi

Approximately 2 billion persons worldwide are infected with schistosomiasis and soil-transmitted helminths (STH), many in areas where endemic malaria transmission coexists. Few data exist on associations between these infections. Nested within a larger clinical trial, primigravid and secundigravid women provided blood samples for human immunodeficiency virus (HIV) testing and peripheral malaria films and stool and urine for evaluation of STH and Schistosoma spp. during their initial antenatal clinic visit. The most common parasitic infections were malaria (37.6%), S. haematobium (32.3%), and hookworm (14.4%); 14.2% of women were HIV-infected. S. haematobium infection was associated with lower malarial parasite densities (344 versus 557 parasites/μL blood; P < 0.05). In multivariate analysis, HIV and hookworm infection were independently associated with malaria infection (adjusted odds ratio = 1.9 and 95% confidence interval = 1.2-3.0 for HIV; adjusted odds ratio = 1.9 and 95% confidence interval = 1.03-3.5 for hookworm). Concurrent helminthic infection had both positive and negative effects on malaria parasitemia among pregnant women in Malawi.

Effects of transmission reduction by insecticide-treated bed nets (ITNs) on parasite genetics population structure: I. The genetic diversity of Plasmodium falciparum parasites by microsatellite markers in western Kenya

Background

Insecticide-treated bed nets (ITNs) reduce malaria transmission and are an important prevention tool. However, there are still information gaps on how the reduction in malaria transmission by ITNs affects parasite genetics population structure. This study examined the relationship between transmission reduction from ITN use and the population genetic diversity of Plasmodium falciparum in an area of high ITN coverage in western Kenya.

Methods

Parasite genetic diversity was assessed by scoring eight single copy neutral multilocus microsatellite (MS) markers in samples collected from P. falciparum-infected children (< five years) before introduction of ITNs (1996, baseline, n = 69) and five years after intervention (2001, follow-up, n = 74).

Results

There were no significant changes in overall high mixed infections and unbiased expected heterozygosity between baseline (%M_A = 94% and H_e = 0.75) and follow up (%M_A = 95% and H_e = 0.79) years. However, locus specific analysis detected significant differences for some individual loci between the two time points. Pfg377 loci, a gametocyte-specific MS marker showed significant increase in mixed infections and H_e in the follow up survey (%M_A = 53% and H_e = 0.57) compared to the baseline (%M_A = 30% and H_e = 0.29). An opposite trend was observed in the erythrocyte binding protein (EBP) MS marker. There was moderate genetic differentiation at the Pfg377 and TAA60 loci (F_ST = 0.117 and 0.137 respectively) between the baseline and post-ITN parasite populations. Further analysis revealed linkage disequilibrium (LD) of the microsatellites in the baseline (14 significant pair-wise tests and I^S_A = 0.016) that was broken in the follow up parasite population (6 significant pairs and I^S_A = 0.0003). The locus specific change in H_e, the moderate population differentiation and break in LD between the baseline and follow up years suggest an underlying change in population sub-structure despite the stability in the overall genetic diversity and multiple infection levels.

Conclusions

The results from this study suggest that although P. falciparum population maintained an overall stability in genetic diversity after five years of high ITN coverage, there was significant locus specific change associated with gametocytes, marking these for further investigation.

Development of an x-ray imaging system for the Laser Megajoule (LMJ)

This imaging system aims at recording images of the core size and shape of an imploding deuterium-tritium (DT) microballoon on LMJ inertial confinement fusion (ICF) experiments. Image acquisition is difficult due to the harsh surrounding created by the fusion reaction, which affects system specifications. This one is made of a scintillator, an optical relay, and a CCD camera shielded from the surrounding. The system was tested on different facilities at CEA/DIF, where a spatial resolution of 120 μm was achieved and gamma dose up to 20 rad effects were measured. Setup and performed test are described.

Bed net ownership in Kenya: the impact of 3.4 million free bed nets

Background

In July and September 2006, 3.4 million long-lasting insecticide-treated bed nets (LLINs) were distributed free in a campaign targeting children 0-59 months old (CU5s) in the 46 districts with malaria in Kenya. A survey was conducted one month after the distribution to evaluate who received campaign LLINs, who owned insecticide-treated bed nets and other bed nets received through other channels, and how these nets were being used. The feasibility of a distribution strategy aimed at a high-risk target group to meet bed net ownership and usage targets is evaluated.

Methods

A stratified, two-stage cluster survey sampled districts and enumeration areas with probability proportional to size. Handheld computers (PDAs) with attached global positioning systems (GPS) were used to develop the sampling frame, guide interviewers back to chosen households, and collect survey data.

Results

In targeted areas, 67.5% (95% CI: 64.6, 70.3%) of all households with CU5s received campaign LLINs. Including previously owned nets, 74.4% (95% CI: 71.8, 77.0%) of all households with CU5s had an ITN. Over half of CU5s (51.7%, 95% CI: 48.8, 54.7%) slept under an ITN during the previous evening. Nearly forty percent (39.1%) of all households received a campaign net, elevating overall household ownership of ITNs to 50.7% (95% CI: 48.4, 52.9%).

Conclusions

The campaign was successful in reaching the target population, families with CU5s, the risk group most vulnerable to malaria. Targeted distribution strategies will help Kenya approach indicator targets, but will need to be combined with other strategies to achieve desired population coverage levels.

The cost-effectiveness of intermittent preventive treatment for malaria in infants in Sub-Saharan Africa

BACKGROUND

Intermittent preventive treatment in infants (IPTi) has been shown to decrease clinical malaria by approximately 30% in the first year of life and is a promising malaria control strategy for Sub-Saharan Africa which can be delivered alongside the Expanded Programme on Immunisation (EPI). To date, there have been limited data on the cost-effectiveness of this strategy using sulfadoxine pyrimethamine (SP) and no published data on cost-effectiveness using other antimalarials.

METHODS

We analysed data from 5 countries in sub-Saharan Africa using a total of 5 different IPTi drug regimens; SP, mefloquine (MQ), 3 days of chlorproguanil-dapsone (CD), SP plus 3 days of artesunate (SP-AS3) and 3 days of amodiaquine-artesunate (AQ3-AS3).The cost per malaria episode averted and cost per Disability-Adjusted Life-Year (DALY) averted were modeled using both trial specific protective efficacy (PE) for all IPTi drugs and a pooled PE for IPTi with SP, malaria incidence, an estimated malaria case fatality rate of 1.57%, IPTi delivery costs and country specific provider and household malaria treatment costs.

FINDINGS

In sites where IPTi had a significant effect on reducing malaria, the cost per episode averted for IPTi-SP was very low, USD 1.36-4.03 based on trial specific data and USD 0.68-2.27 based on the pooled analysis. For IPTi using alternative antimalarials, the lowest cost per case averted was for AQ3-AS3 in western Kenya (USD 4.62) and the highest was for MQ in Korowge, Tanzania (USD 18.56). Where efficacious, based only on intervention costs, IPTi was shown to be cost effective in all the sites and highly cost-effective in all but one of the sites, ranging from USD 2.90 (Ifakara, Tanzania with SP) to USD 39.63 (Korogwe, Tanzania with MQ) per DALY averted. In addition, IPTi reduced health system costs and showed significant savings to households from malaria cases averted. A threshold analysis showed that there is room for the IPTi-efficacy to fall and still remain highly cost effective in all sites where IPTi had a statistically significant effect on clinical malaria.

CONCLUSIONS

IPTi delivered alongside the EPI is a highly cost effective intervention against clinical malaria with a range of drugs in a range of malaria transmission settings. Where IPTi did not have a statistically significant impact on malaria, generally in low transmission sites, it was not cost effective.

Rotavirus disease burden and impact and cost-effectiveness of a rotavirus vaccination program in kenya

BACKGROUND

The projected impact and cost-effectiveness of rotavirus vaccination are important for supporting rotavirus vaccine introduction in Africa, where limited health intervention funds are available.

METHODS

Hospital records, health utilization surveys, verbal autopsy data, and surveillance data on diarrheal disease were used to determine rotavirus-specific rates of hospitalization, clinic visits, and deaths due to diarrhea among children <5 years of age in Nyanza Province, Kenya. Rates were extrapolated nationally with use of province-specific data on diarrheal illness. Direct medical costs were estimated using record review and World Health Organization estimates. Household costs were collected through parental interviews. The impact of vaccination on health burden and on the cost-effectiveness per disability-adjusted life-year and lives saved were calculated.

RESULTS

Annually in Kenya, rotavirus infection causes 19% of hospitalizations and 16% of clinic visits for diarrhea among children <5 years of age and causes 4471 deaths, 8781 hospitalizations, and 1,443,883 clinic visits. Nationally, rotavirus disease costs the health care system $10.8 million annually. Routine vaccination with a 2-dose rotavirus vaccination series would avert 2467 deaths (55%), 5724 hospitalizations (65%), and 852,589 clinic visits (59%) and would save 58 disability-adjusted life-years per 1000 children annually. At $3 per series, a program would cost $2.1 million in medical costs annually; the break-even price is $2.07 per series.

CONCLUSIONS

A rotavirus vaccination program would reduce the substantial burden of rotavirus disease and the economic burden in Kenya.

Daily Trimethoprim-Sulfamethoxazole Prophylaxis Rapidly Induces Corresponding Resistance Among IntestinalEscherichia coliof HIV-Infected Adults in Kenya

Background. Trimethoprim-sulfamethoxazole (TMP-SMZ) has been recommended by World Health Organization (WHO) as daily prophylaxis for Africans with AIDS to prevent opportunistic infections. Daily TMP-SMZ may reduce its susceptibility to commensal intestinal Escherichia coli (E coli), increasing the burden of TMP-SMZ-resistant pathogens. Methods. Participants received either daily TMP-SMZ (CD4 <350 cells/mm3) or daily multivitamins (MVIs; CD4 ≥350 cells/mm3) for 6 months. Stool was collected at baseline, 2 weeks, 2 months, and 6 months. A random E coli was tested for susceptibility. Results. Baseline prevalence of TMP-SMZ resistance ranged from 71% to 81% and was not different across CD4 strata. At 2 weeks, prevalence of TMP-SMZ-resistant E coli increased significantly from 78% to 98% (P < .001) among persons taking daily TMP-SMZ and did not change among persons taking MVIs. Conclusions. Daily prophylaxis with TMP-SMZ induced in vivo resistance to the drug after 2 weeks. Empiric therapy for diarrhea with agents other than TMP-SMZ should be considered for HIV-infected persons receiving daily TMP-SMZ prophylaxis.

Performance of malaria rapid diagnostic tests as part of routine malaria case management in Kenya

Data on malaria rapid diagnostic test (RDT) performance under routine program conditions are limited. We assessed the attributes of RDTs performed by study and health facility (HF) staffs as part of routine malaria case management of patients > or = 5 years of age in Kenya. Expert microscopy was used as our gold standard. A total of 1,827 patients were enrolled; 191 (11.6%) were parasitemic by expert microscopy. Sensitivity and specificity of RDTs performed by study staff were 86.6% (95% confidence interval [CI]: 79.8-93.5%) and 95.4% (95% CI: 93.9-96.9%), respectively. Among tests performed by HF staff, RDTs were 91.7% (95% CI: 80.8-100.0%) sensitive and 96.7% (95% CI: 92.8-100.0%) specific, whereas microscopy was 52.5% (95% CI: 33.2-71.9%) sensitive and 77.0% (95% CI: 67.9-86.2%) specific. Our findings suggest that RDTs perform better than microscopy under routine conditions. Further efforts are needed to maintain this high RDT performance over time.

Efficacy and safety of artemether-lumefantrine dispersible tablets compared with crushed commercial tablets in African infants and children with uncomplicated malaria: a randomised, single-blind, multicentre trial

BACKGROUND

Combination treatments, preferably containing an artemisinin derivative, are recommended to improve efficacy and prevent Plasmodium falciparum drug resistance. Our aim was to show non-inferiority of a new dispersible formulation of artemether-lumefantrine to the conventional crushed tablet in the treatment of young children with uncomplicated malaria.

METHODS

We did a randomised non-inferiority study on children weighing 5-35 kg with uncomplicated P falciparum malaria in Benin, Kenya, Mali, Mozambique, and Tanzania. The primary outcome measure was PCR-corrected 28-day parasitological cure rate. We aimed to show non-inferiority (with a margin of -5%) of dispersible versus crushed tablet. We constructed an asymptotic one-sided 97.5% CI on the difference in cure rates. A computer-generated randomisation list was kept centrally and investigators were unaware of the study medication administered. We used a modified intention-to-treat analysis. This trial is registered with ClinicalTrials.gov, number NCT00386763.

FINDINGS

899 children aged 12 years or younger were randomly assigned to either dispersible (n=447) or crushed tablets (n=452). More than 85% of patients in each treatment group completed the study. 812 children qualified for the modified intention-to-treat analysis (n=403 vs n=409). The PCR-corrected day-28 cure rate was 97.8% (95% CI 96.3-99.2) in the group on dispersible formulation and 98.5% (97.4-99.7) in the group on crushed formulation. The lower bound of the one-sided 97.5% CI was -2.7%. The most common drug-related adverse event was vomiting (n=33 [7%] and n=42 [9%], respectively). No signs of ototoxicity or relevant cardiotoxicity were seen.

INTERPRETATION

A six-dose regimen of artemether-lumefantrine with the new dispersible formulation is as efficacious as the currently used crushed tablet in infants and children, and has a similar safety profile.

Control of oestradiol secretion and of cytochrome P450 aromatase messenger ribonucleic acid accumulation by FSH involves different intracellular pathways in oestrogenic bovine granulosa cells in vitro

The objective of this study was to determine the major intracellular signalling pathways used by FSH and insulin to stimulate cytochrome P450 aromatase (Cyp19) mRNA and oestradiol accumulation in oestrogenic bovine granulosa cells in vitro. Bovine granulosa cells from small follicles (2-4 mm diameter) were cultured for 6 days under non-luteinizing conditions in the presence of insulin at 100 ng/ml, or insulin (10 ng/ml) and FSH (1 ng/ml). On day 4 of culture, specific inhibitors of phosphatidylinositol 3-kinase (PI3K; LY-294002), protein kinase C (PKC; GF-109203X), protein kinase A (PKA; H-89) or mitogen-activated protein (MAP) kinase activation (PD-98059) were added. The addition of PI3K and PKC inhibitors, but not of PKA inhibitor, significantly decreased insulin-stimulated Cyp19 mRNA levels and oestradiol accumulation (P < 0.001). The PKA inhibitor significantly decreased FSH-stimulated Cyp19 mRNA abundance and oestradiol secretion, whereas PI3K and PKC inhibitors decreased oestradiol secretion without affecting Cyp19 mRNA accumulation. Inhibition of MAP kinase pathway significantly increased Cyp19 mRNA abundance in insulin- and FSH-stimulated cells. P450scc mRNA levels and progesterone secretion were not affected by any inhibitor in either experiment. Although FSH stimulates Cyp19 expression predominantly through PKA, oestradiol secretion is altered by PI3K and PKC pathways independently of Cyp19 mRNA levels. In addition, we suggest that Cyp19 is under tonic inhibition mediated through a MAP kinase pathway.

Randomized trial of 2-dose versus monthly sulfadoxine-pyrimethamine intermittent preventive treatment for malaria in HIV-positive and HIV-negative pregnant women in Malawi

BACKGROUND

Intermittent preventive treatment during pregnancy (IPTp) with sulfadoxine-pyrimethamine (SP) decreases placental malaria parasitemia and associated maternal anemia, premature delivery, and low birth weight. However, the optimal regimen in the setting of a high prevalence of human immunodeficiency virus (HIV) infection remains unclear.

METHODS

In Malawi, where the efficacy of SP for the treatment of malaria in children is decreasing, we conducted a randomized, nonblinded study to compare the efficacy of monthly SP IPTp with a 2-dose regimen for the prevention of placental parasitemia in HIV-positive and -negative primigravid and secundigravid women.

RESULTS

Of HIV-positive women, 7.8% who received monthly SP had placental malaria, compared with 21.5% of those who received 2-dose SP (relative risk [RR], 0.36 [95% confidence interval {CI}, 0.17-0.79]). Of HIV-negative women, 2.3% who received monthly SP and 6.3% who received 2-dose SP had placental malaria (RR, 0.37 [95% CI, 0.11-1.19]). Less than 1% of women reported adverse drug reactions, with no increase in HIV-positive women or those who received monthly SP.

CONCLUSIONS

In HIV-positive pregnant women, monthly SP IPTp is more efficacious than a 2-dose regimen in preventing placental malaria. The study also demonstrates the continued efficacy of SP for the prevention of placental malaria, even in the face of its decreasing efficacy for the treatment of malaria in children. In areas with intense transmission of falciparum malaria and a high prevalence of HIV infection, monthly SP IPTp should be adopted.

Antifolate resistance in Plasmodium falciparum: multiple origins and identification of novel dhfr alleles

BACKGROUND

Sulfadoxine-pyrimethamine has been widely used as first-line therapy for uncomplicated malaria throughout sub-Saharan Africa. Recent studies conducted in Asia and Africa suggest the triple-mutant dhfr genotype (51I/59R/108N) may have been generated as a single event in Southeast Asia, with subsequent spread of the single lineage to the African continent, but this hypothesis needs further validation.

METHODS

Direct sequencing of polymerase chain reaction (PCR) products, pyrosequencing, and cloning of PCR products were utilized to identify mutations in dhfr. To investigate the evolutionary history of dhfr alleles, we assayed microsatellite loci flanking dhfr along chromosome 4.

RESULTS

A total of 15 of 479 samples from western Kenya showed the presence of I164L, in 5 different genotypes. We document C50R in 2 of our samples. Using microsatellite markers, we show 2 haplotypes for both the 51I/108N/164L and 51I/59R/108N/164L genotypes. Our results also show multiple lineages for the triple-mutant dhfr genotype in Africa.

CONCLUSIONS

These findings highlight the importance of local characterization of alleles before molecular surveillance of drug-resistant alleles is considered in different endemic settings and populations.

Novel Antibiotic-Resistant Pneumococcal Strains Recovered from the Upper Respiratory Tracts of HIV-Infected Adults and Their Children in Kisumu, Kenya

In a survey of genetic diversity within penicillin-nonsusceptible pneumococcal isolates in Kenya, we examined 162 upper respiratory isolates from 104 human immunodeficiency virus (HIV)-infected adults and 46 children in a cotrimoxazole prophylaxis study. Antibiotic resistance levels were high; 152 (94.4%) were cotrimoxazole nonsusceptible (134 fully resistant) and 124 (77%) were intermediately penicillin resistant. Isolates nonsusceptible to penicillin and cotrimoxazole (PNCNP) were found among 24 of the 29 serotypes encountered, 15 of which have rarely or never had documented nonsusceptibility to penicillin. These included serotypes 3, 4, 7C, 7F, 10A, 11A, 13, 15A, 15B, 16F, 17F, 19B, 21, 35A, and 35B. Segments of pbp2b genes from 9 PNCNP (serotypes 3, 13, 15A, 16F, 20, and 35A) were typical of resistance-conferring alleles in that they were highly divergent and contained two substitutions thought to be critical for resistance. Similarly, the dhfr genes from 3 PNCNP were divergent and contained a substitution required for cotrimoxazole resistance. Multilocus sequence typing (MLST) of 48 PNCNP revealed 33 sequence types (STs), none of which were previously recorded at http://www.mlst.net. Comparisons with all known STs revealed that 23 of these STs were unrelated to other known STs, whereas 10 STs were highly related to STs from internationally disseminated strains, including 2 of the 26 antibiotic-resistant clones recognized by the Pneumococcal Molecular Epidemiology Network. Based upon differing serotypes expressed by strains of identical or closely similar genotypes, there has been an extensive history of capsular switching within seven genetic clusters represented by these 10 STs and related STs described at http://www.mlst.net.

[Lengthening temporalis myoplasty and transfacial nerve graft (VII-V). Technical note]

Authors report the first five cases of lengthening temporalis myoplasty associated with transfacial nerve grafting. After a follow-up period of 10 months and 8 months for the 2 first cases, temporalis reinnervation by the facial nerve could be observed. Nerve growth was documented by electromyography. Three other cases have been performed using this technique and are in the nerve growth phase. Operative technique is described in detail. Transfacial nerve grafting seems to help the transposed temporalis muscle obtain more facial function and therefore, improve the quality of the spontaneous smile. The temporalis muscle become double innervated (trigeminal and facial nerve). It should be indicated in children, young adults or in patients in whom physical therapy will be difficult.

[Effect of the imidazoline receptor agonist moxonidine on hemodynamics, coronary circulation, metabolic ischemia markers and the neurohumoral system in patients with essential hypertension. Effects of moxonidine on coronary circulation]

Moxonidine is a new centrally active imidazoline-receptor agonist being effectively applied in the treatment of arterial hypertension due to its sympathicolytic potency. This is the first investigation regarding the effects of moxonidine on coronary and systemic hemodynamics, metabolic markers of ischemia and neurohumoral parameters in patients with essential hypertension (WHO I-II). We studied moxonidine (single dose of 0.4 mg p.o.) in 22 patients with left ventricular (LV) hypertrophy, ST segment depressions during exercise, pectanginal complaints and negative coronarograms. Assessments included arterial blood pressure, cardiac output, pulmonary artery pressure mean (PAPm), pulmonary capillary wedge pressure (PCWP) and coronary sinus flow (CSF) by intravascular Doppler technique. The moxonidine-induced parameter changes 2 hours later were as follows: a decrease in systolic/diastolic pressure by 28/10 mmHg, and in heart rate by 5 bpm, associated with a decline of PAPm by 17% and of PCWP by 26%. LV work was reduced by 26%, MVO2 by 18% and CSF by 16%. Average peak velocity in CS fell by 18% and coronary flow reserve (with adenosine) increased by 12%. CS-O2 saturation rose by 4%, accompanied by an increase in lactate extraction by 17%, a decrease in norepinephrine spillover by 30% and in arterial endotheline by 20%. In conclusion, moxonidine produces clinically relevant sympathicolysis with beneficial effects on hemodynamics, coronary circulation and neurohumoral parameters.

[Actions of standardized extracts of Crataegus berries on exercise tolerance and quality of life in patients with congestive heart failure]

Standardized extracts of Crataegus leaves and blossoms are said to have positive inotropic, positive dromotropic and negative bathmotropic effects. Clinical trials produce evidence for an improvement of symptoms in patients with congestive heart failure (NYHA II). In this trial the efficacy of a standardized extract of fresh Crataegus berries (Rob 10) on exercise tolerance and quality of life was studied in 88 patients. In a three-month placebo-controlled, randomized, double-blind trial these patients were treated with Rob 10 (3 x 25 drops daily). Total exercise time in bicycle ergometry was defined as primary efficacy variable, while quality of life (Minnesota Questionnaire), Dyspnea-Fatigue Index and the assessment of dyspnea by the patient on a visual analogous scale were chosen as secondary parameters. Investigations were performed after a two week placebo run-in period as well as 6 and 12 weeks after the onset of the study. Treatment with Rob 10 led to a increase of exercise time of 38.9 s vs placebo (95% confidence interval 5.7-72.1 s). Quality of life improved accordingly in favour of Rob 10. In the Minnesota Questionnaire, the total score fell by 31% (30.6 vs 44.1) under Rob 10 vs 18% (34.6 vs 42.4) under placebo. The Dyspnea-Fatigue Index demonstrated an increase of the total score of 12% (9.41 vs 8.37) vs 8% (8.92 vs 8.26) under administration of placebo. According to findings of the assessment of dyspnea by the patient, dyspnea decreased by 11% (50.5 vs 56.6 mm) vs 4% (54.8 vs 57.3 mm) under placebo. The present study proves the efficacy and safety of a standardized extract of fresh Crataegus berries (Rob 10) in patients with congestive heart failure (NYHA II) regarding the parameters evaluated.

Deep sclerectomy with collagen implant in patients with glaucoma and high myopia

PURPOSE

To study prospectively the success rate and complications of deep sclerectomy with collagen implant (DSCI), a nonpenetrating filtration procedure, in patients with glaucoma and high myopia.

SETTING

Glaucoma Unit, Hôpital Ophtalmique Jules Gonin, Lausanne, Switzerland.

METHODS

This nonrandomized prospective trial comprised 21 eyes of 21 highly myopic patients with medically uncontrolled primary or secondary open-angle glaucoma. Visual acuity, intraocular pressure (IOP), and slitlamp examinations were performed before as well as 1 and 7 days and 1, 3, 6, 9, 12, 18, 24, 30, 36, 42, 48, 54, 60, and 66 months postoperatively. Visual field examinations were repeated every 6 months. Exclusion criteria were known allergy to collagen, advanced lens opacity, and eye surgery or laser trabeculoplasty fewer than 6 months before enrollment.

RESULTS

The mean follow-up was 44.0 months +/- 17.1 (SD). The mean preoperative IOP of 26.4 +/- 5.9 mm Hg dropped to 10.4 +/- 6.1 mm Hg at 48 months. Eighty-one percent of patients achieved an IOP below 21 mm Hg with or without medication at 48 months. Thirty-eight percent had an IOP below 21 mm Hg without medication. The mean number of medications per patient was reduced from 2.30 +/- 0.85 to 0.86 +/- 0.91.

CONCLUSIONS

Deep sclerectomy with collagen implant provided reasonable control of IOP in patients with glaucoma and high myopia over a long-term follow-up. There were relatively few postoperative complications.

The hepatitis C virus NS5B RNA-dependent RNA polymerase activity and susceptibility to inhibitors is modulated by metal cations

OBJECTIVES

The aim of this study was to understand the effect of metal cations on the hepatitis C virus (HCV) NS5B in vitro RNA-dependent RNA polymerase (RdRp) activity and its susceptibility to various inhibitors.

METHODS

A recombinant full-length HCV NS5B protein was expressed in insect cells and purified to homogeneity. RdRp activity was assessed using standard filtration or polyacrylamide gel-based assays.

RESULTS

Efficient inhibition of the HCV NS5B RdRp activity by gliotoxin, as well as by various substrate analogs, occurs in the presence of Mn2+, but not of Mg2+. Assays performed in the presence of both cofactors suggest that, in vitro, the enzyme's affinity for Mn2+ is higher than that for Mg2+. In addition, the RdRp activity, displayed in the presence of heteropolymeric templates, is significantly increased when the metal cofactor consists of Mn2+. Finally, steady state kinetics showed that the velocity of the reaction, as well as the affinity of the enzyme for its substrate, could both be affected by the nature of the divalent metal cation used.

A study of nonpatient preadolescent Rorschach protocols

There is a paucity of peer-reviewed, nonpatient Rorschach studies in psychological journals, particularly for children. This study examined 100 preteenage children, using the Comprehensive System to code their Rorschach protocols. The participants were also evaluated with the Conners Parent Rating Scale-93 (Conners, 1989) and 5 exclusionary behavior criteria. The 100 participants demonstrated better than average behaviors. The results presented include all the ratios and indexes found in the nonpatient statistics for the Comprehensive System. We discuss interrater reliability issues and offer recommendations for further cross-validating research.

A novel high throughput screening assay for HCV NS3 helicase activity

A novel assay for measurement of Hepatitis C virus (HCV) NS3 helicase activity was developed using Flashplate technology. This assay involves the use of a DNA duplex substrate and recombinant HCV NS3 produced in Escherichia coli. The DNA duplex consisted of a pair of oligonucleotides, one biotinylated, the other radiolabeled at their respective 5' termini. This DNA duplex was immobilized, via the biotin molecule, on the surface of a neutravidin-coated SMP103 Flashplate (NEN Life Science Products). Helicase activity results in the release of the radiolabeled oligonucleotide, which translates in signal reduction with respect to control wells. Biochemical characterization of the HCV NS3 helicase activity was performed using this assay. We demonstrated that the NS3-mediated unwinding is proportional to both the amount of DNA substrate in the well, and to the NS3 concentration in the reaction. Most of the NS3-mediated unwinding was achieved in the initial 60 min of incubation. As expected the reactions were ATP-dependent and found to be affected by the concentration of MgCl(2), MnCl(2), KCl, EDTA, and by pH. We found this assay to be highly reproducible since only slight variation was observed when a total of 68 helicase reactions were performed on one plate. Therefore, this Flashplate helicase assay is fast, convenient and reproducible. These criteria make it suitable for high throughput screening of potential NS3 helicase inhibitors.

[Asthenopic symptoms in cervical vertebrae syndrome]

The vertebral cervical syndrome is a clinical entity defined as a dysfunction of the cranio-cervical junction of traumatic or non traumatic cause. The authors report on asthenopic disorders occurring in such a syndrome. The fusion amplitude and the accommodation power were reduced in all patients and were a cause of delayed job recurrence. The treatment of fusion was long, painful and, in some cases, not successful. A depressive status associated with a prolonged job interruption were bad prognosis factors. A differential diagnosis has to be made with the so-called insurance neurotic reaction.

The R1 subunit of herpes simplex virus ribonucleotide reductase is a good substrate for host cell protein kinases but is not itself a protein kinase

The N terminus of the R1 subunit of herpes simplex virus type 2 ribonucleotide reductase is believed to be a protein kinase domain mainly because the R1 protein was phosphorylated in a protein kinase assay on blot. Using Escherichia coli and adenovirus expression vectors to produce R1, we found that, whereas the reductase activity of both recombinant proteins was similar, efficient phosphorylation of R1 and casein in the presence of Mg2+ was obtained only with the R1 purified from eukaryotic cells. Phosphorylation of this R1, in solution or on blot, results mainly from the activity of casein kinase II (CKII), a co-purifying protein kinase. Labeling on blot occurs from CKII leakage off the membrane and its subsequent high affinity binding to in vivo CKII-phosphorylated R1. CKII target sites were mapped to an acidic serine-rich segment of the R1 N terminus. Improvement in purification of the R1 expressed in eukaryotic cells nearly completely abolished its phosphorylation potential. An extremely low level of phosphorylation observed in the presence of Mn2+ with the R1 produced in E. coli was probably due to an unidentified prokaryotic protein kinase. These results provide evidence that the herpes simplex virus type 2 R1 does not possess an intrinsic protein kinase activity.

Clinical and methodological factors related to reliability of the best-estimate diagnostic procedure

OBJECTIVE

The reliability and accuracy of the best-estimate diagnostic procedure were examined, and factors associated with reliability were determined.

METHOD

The subjects were 134 members of large multigenerational pedigrees densely affected by bipolar disorders or schizophrenia. Three best-estimate diagnoses were derived: first, by a research psychiatrist and research assistant unblind to the relatives' diagnoses; second, by two blind independent psychiatrists; third, by a panel of four blind psychiatrists. The subjects were characterized on several clinical and methodological variables, which were used to compare the agreements of two types of best-estimate diagnoses with the disagreements.

RESULTS

There was satisfactory agreement between the unblind and blind consensus best-estimate diagnoses and between the two blind independent psychiatrists. Latent class analyses revealed that limited sensitivity was the main source of imperfect reliability. Confusability analyses revealed that the most problematic diagnostic distinctions involved schizoaffective disorder, which was confused with schizophrenia, bipolar I disorder, and schizophreniform disorder. Blindness significantly affected diagnostic outcome in latent class analyses. Moreover, for diagnostic disagreements, unblind diagnoses had greater continuity with the most predominant diagnosis in the pedigree than did blind diagnoses. Diagnostic disagreements were associated with the presence of mixed affective and psychotic symptoms, less diagnostic certainty, and shorter duration of illness.

CONCLUSIONS

These results suggest that it is possible to identify cases that are more likely to lead to diagnostic disagreements in family and epidemiological studies and that blind diagnoses may help to prevent false positive diagnoses, which may be particularly detrimental to genetic linkage analyses.

Long-term stability of diagnosis and symptom dimensions in a systematic sample of patients with onset of schizophrenia in childhood and early adolescence. II: Postnegative distinction and childhood predictors of adult outcome

BACKGROUND

The aim of this study was to verify the presence and stability across life of the positive/negative distinction in early-onset schizophrenia (EO-SZ) through a longitudinal factor analysis of the schizophrenic dimensions, and to identify the factors predicting several indices of long-term outcome for EO-SZ.

METHOD

Forty children consecutively referred for DSM-III-R schizophrenia (SZ) in a specific catchment area comprised the sample.

RESULTS

Across a 14.8-year follow-up, longitudinal factor analysis identified two separate factors corresponding to the positive and negative symptom dimensions. We also observed that: the GAS rated over the last three years of adult illness and the severity of negative symptoms during the stabilised interepisode intervals in adulthood were the indices of adult outcome that were most easily predicted; and the best childhood predictors of adult outcome were premorbid functioning and severity of positive and negative symptoms during acute episodes.

CONCLUSIONS

The presence of premorbid non-psychotic behaviour disturbances (NPBD) and premorbid developmental problems was not related to severity of outcome, in contrast to the former variables.

Long-term stability of diagnosis and symptom dimensions in a systematic sample of patients with onset of schizophrenia in childhood and early adolescence. I: nosology, sex and age of onset

BACKGROUND

Little is known about the long-term outcome of schizophrenia that has its onset during childhood and early adolescence (early-onset schizophrenia, or EO-SZ). Whether or not EO-SZ is an aetiologically separate form of schizophrenia (SZ) is unresolved.

METHOD

The study was a 14.8-year follow-up, using methods such as systematic sampling, evaluation of possible non-respondent bias, consensus best-estimate diagnoses (DSM-III-R) made independently in childhood and adulthood, measures of positive and negative dimensions, of non-psychotic behaviour disturbances (NPBD) and of developmental problems before the appearance of SZ.

RESULTS

There was high stability of EO-SZ (n = 40) diagnoses (mean onset at 14.0 years) until adulthood (mean age at follow-up 28.8 years) but a lower stability of positive and negative schizophrenic dimensions. There was a poor outcome of EO-SZ, a strong over-representation of males but few gender differences, and no effect of age of onset on clinical features and outcome.

CONCLUSIONS

EO-SZ taken as a whole shows no qualitative differences to adult-onset SZ. However, a distinction through the onset of preschizophrenic developmental problems or NPBD might be a way to investigate heterogeneity within EO-SZ.

Identification and functional analysis of Ly-6A/E as a thymic and bone marrow stromal antigen

We recently described an mAb (MTS23) reactive with a membrane Ag expressed on a subset of thymic medullary stromal cells. This Ag is also constitutively expressed at high levels on peripheral B cells, macrophages, and thymic and splenic dendritic cells of C57BL/6 mice. A number of stromal cell lines derived from thymus and bone marrow also stain with MTS23, but thymocytes and peripheral T cells only weakly express the Ag detected by MTS23. Here we show that the molecule detected by MTS23 is a member of the Ly-6 family of phosphatidylinositol-anchored membrane proteins. Treatment of stromal cells with phosphatidylinositol-phospholipase C before staining completely abolished expression. Using transient expression of 293T cells and a cDNA library of a stromal cell line cloned into the pEF-BOS vector, a cDNA encoding the MTS23-target Ag was isolated. Partial sequencing and restriction enzyme mapping revealed that it represents the Ly-6A/E protein. While the physiologic significance of the presence of Ly-6 molecules on stromal cells is not clear, it has been known for some time that, at least in lymphocytes, cellular activation events can be induced upon Ly-6 engagement. We now demonstrate that Ly-6 also functions as a signal transduction molecule on stromal cells, in that granulocyte-macrophage CSF can be produced by a variety of stromal cell lines upon mAb-mediated cross-linking of Ly-6. Together with the dramatic up-regulation of Ly-6 expression on stromal cells upon IFN-gamma treatment, this is the first indication of a biologic function of an Ly-6 gene product on nonhemopoietic cells. The results suggest that Ly-6 may play a role in the cross-talk between lymphocyte precursors and stromal cells.