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A comprehensive understanding of the spatial distribution and correlates of infection are key for the planning of disease control programs and assessing the feasibility of elimination and/or eradication. In this work, we used species distribution modeling to predict the environmental suitability of the Guinea worm (Dracunculus medinensis) and identify important climatic and sociodemographic risk factors. Using Guinea worm surveillance data collected by the Chad Guinea Worm Eradication Program (CGWEP) from 2010 to 2022 in combination with remotely sensed climate and sociodemographic correlates of infection within an ensemble machine learning framework, we mapped the environmental suitability of Guinea worm infection in Chad. The same analytical framework was also used to ascertain the contribution and influence of the identified climatic risk factors. Spatial distribution maps showed predominant clustering around the southern regions and along the Chari River. We also identified areas predicted to be environmentally suitable for infection. Of note are districts near the western border with Cameroon and southeastern border with Central African Republic. Key environmental correlates of infection as identified by the model were proximity to permanent rivers and inland lakes, farmlands, land surface temperature, and precipitation. This work provides a comprehensive model of the spatial distribution of Guinea worm infections in Chad 2010-2022 and sheds light on potential environmental correlates of infection. As the CGWEP moves toward elimination, the methods and results in this study will inform surveillance activities and help optimize the allocation of intervention resources.

Disease ecologists now recognize the limitation behind examining host-parasite interactions in isolation: community members-especially predators-dramatically affect host-parasite dynamics. Although the initial paradigm was that predation should reduce disease in prey populations ("healthy herds hypothesis"), researchers have realized that predators sometimes increase disease in their prey. These "predator-spreaders" are now recognized as critical to disease dynamics, but empirical research on the topic remains fragmented. In a narrow sense, a "predator-spreader" would be defined as a predator that mechanically spreads parasites via feeding. However, predators affect their prey and, subsequently, disease transmission in many other ways such as altering prey population structure, behavior, and physiology. We review the existing evidence for these mechanisms and provide heuristics that incorporate features of the host, predator, parasite, and environment to understand whether or not a predator is likely to be a predator-spreader. We also provide guidance for targeted study of each mechanism and quantifying the effects of predators on parasitism in a way that yields more general insights into the factors that promote predator spreading. We aim to offer a better understanding of this important and underappreciated interaction and a path toward being able to predict how changes in predation will influence parasite dynamics., (© 2023 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.)

The healthy herds hypothesis (HHH) suggests that predators decrease parasitism in their prey. Repeated tests of this hypothesis across a range of taxa and ecosystems have revealed significant variation in the effect of predators on parasites in prey. Differences in the response to predators (1) between prey taxa, (2) between seasons, and (3) before and after catastrophic disturbance are common in natural systems, but typically ignored in empirical tests of the HHH. We used a predator exclusion experiment to measure the effect of these heterogeneities on the tri-trophic interaction among predators, parasites and prey. We experimentally excluded mammalian predators from the habitats of hispid cotton rats (Sigmodon hispidus) and cotton mice (Peromyscus gossypinus) and measured the effect of exclusion on gastrointestinal parasites in these rodents. Our experiment spanned multiple seasons and before and after a prescribed burn. We found that the exclusion of the same predators had opposite effects on the parasites of small mammal prey species. Additionally, we found that the effect of mammal exclusion on parasitism differed before versus after fire disturbance. Finally, we saw that the effect of predator exclusion was highly dependent on prey capture season. Significant effects of exclusion emerged primarily in the fall and winter months. The presence of so many different effects in one relatively simple system suggests that predator effects on parasites in prey are highly context dependent., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective: More similar locations may have similar infectious disease dynamics. There is clear overlap in putative causes for epidemic similarity, such as geographic distance, age structure, and population size. We compare the effects of these potential drivers on epidemic similarity compared to a baseline assumption that differences in the basic reproductive number ( R 0 ) will translate to differences in epidemic trajectories., Methods: Using COVID-19 case counts from United States counties, we explore the importance of geographic distance, population size differences, and age structure dissimilarity on resulting epidemic similarity., Results: We find clear effects of geographic space, age structure, population size, and R 0 on epidemic similarity, but notably the effect of age structure was stronger than the baseline assumption that differences in R 0 would be most related to epidemic similarity., Conclusions: Together, this highlights the role of spatial and demographic processes on SARS-CoV2 epidemics in the United States., Competing Interests: The authors have no conflicts of interest to declare., (© 2022 The Authors.)

The large spatial scale, geographical overlap, and similarities in transmission mode between the 1918 H1N1 influenza and 2020 SARS-CoV-2 pandemics together provide a novel opportunity to investigate relationships between transmission of two different diseases in the same location. To this end, we use initial exponential growth rates in a Bayesian hierarchical framework to estimate the basic reproductive number, R 0 , of both disease outbreaks in a common set of 43 cities in the United States. By leveraging multiple epidemic time series across a large spatial area, we are able to better characterize the variation in R 0 across the United States. Additionally, we provide one of the first city-level comparisons of R 0 between these two pandemics and explore how demography and outbreak timing are related to R 0 . Despite similarities in transmission modes and a common set of locations, R 0 estimates for COVID-19 were uncorrelated with estimates of pandemic influenza R 0 in the same cities. Also, the relationships between R 0 and key population or epidemic traits differed between diseases. For example, epidemics that started later tended to be less severe for COVID-19, while influenza epidemics exhibited an opposite pattern. Our results suggest that despite similarities between diseases, epidemics starting in the same location may differ markedly in their initial progression., (© The Author(s) 2022. Published by Oxford University Press on behalf of National Academy of Sciences.)

Background: Finding effective ways to increase physical activity immediately following high-dose chemotherapy and autologous hematopoietic cell transplantation (HCT) for treatment of multiple myeloma (MM) is challenging., Objective: This pilot randomized clinical trial tested the acceptability, feasibility, and preliminary effects of a free-living physical activity intervention (STEPS) compared with usual care (UC) on physical activity, fatigue, muscle strength, functional ability, sleep, and quality of life following treatment for MM with HCT., Methods: Using a 2-group pretest/posttest design (N = 32), this study compared the 6-week STEPS intervention to UC. Data were collected using self-report questionnaires, functional performance tests, and wrist actigraphy before HCT and 7 weeks following hospital discharge., Results: The STEPS group achieved their physical activity goals on 53% of intervention days. The STEPS group experienced greater appetite loss, more diarrhea, and slept more than UC regardless of time point. Both groups reported improvements in mental fatigue, emotional functioning, pain, sleep disturbance, anger, anxiety, and depression but climbed stairs slower and had weaker hand grips after intervention. Both groups subjectively reported fewer sleep disturbances but objectively experienced more wakefulness after sleep onset and an increased number of awakenings postintervention., Conclusions: The STEPS intervention is acceptable and feasible for people with MM treated with HCT. Both groups reported some improved symptoms but experienced some declines in physical performance postintervention., Implications for Practice: Nurses strive to optimize health and promote well-being. Helping people increase their physical activity after treatment for MM with HCT may improve symptoms, but additional studies are needed., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Domestic dogs have an important role in the ecology of transmission of the Guinea worm, a debilitating human parasite. A new study documents how fish content in dogs' diets can predict Guinea worm infection status, suggesting additional avenues for control., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Dracunculus medinensis (Guinea worm [GW]), a zoonotic nematode targeted for eradication, has been managed using interventions aimed at humans; however, increases in domestic dog GW infections highlight the need for novel approaches. We conducted two clinical trials evaluating the efficacy of subcutaneously injected flubendazole (FBZ) as a treatment of GW infection. The first trial was conducted administering FBZ to experimentally infected ferrets; the second trial involved administering FBZ or a placebo to domestic dogs in the Republic of Tchad (Chad). We found contrasting results between the two trials. When adult gravid female GW were recovered from ferrets treated with FBZ, larvae presented in poor condition, with low to no motility, and an inability to infect copepods. Histopathology results indicated a disruption to morulae development within uteri of worms from treated animals. Results from the trial in Chadian dogs failed to indicate significant treatment of or prevention against GW infection. However, the difference in treatment intervals (1 month for ferrets and 6 months for dogs) or the timing of treatment (ferrets were treated later in the GW life-cycle than dogs) could explain different responses to the subcutaneous FBZ injections. Both trials provided valuable data guiding the use of FBZ in future trials (such as decreasing treatment intervals or increasing the dose of FBZ in dogs to increase exposure), and highlighted important lessons learned during the implementation of a field-based, double-blinded randomized control trial in Chadian dogs.

Few human infectious diseases have been driven as close to eradication as dracunculiasis, caused by the Guinea worm parasite (Dracunculus medinensis). The number of human cases of Guinea worm decreased from an estimated 3.5 million in 1986 to mere hundreds by the 2010s. In Chad, domestic dogs were diagnosed with Guinea worm for the first time in 2012, and the numbers of infected dogs have increased annually. The presence of the parasite in a non-human host now challenges efforts to eradicate D. medinensis, making it critical to understand the factors that correlate with infection in dogs. In this study, we evaluated anthropogenic and environmental factors most predictive of detection of D. medinensis infection in domestic dog populations in Chad. Using boosted regression tree models to identify covariates of importance for predicting D. medinensis infection at the village and spatial hotspot levels, while controlling for surveillance intensity, we found that the presence of infection in a village was predicted by a combination of demographic (e.g. fishing village identity, dog population size), geographic (e.g. local variation in elevation), and climatic (e.g. precipitation and temperature) factors, which differed between northern and southern villages. In contrast, the presence of a village in a spatial infection hotspot, was primarily predicted by geography and climate. Our findings suggest that factors intrinsic to individual villages are highly predictive of the detection of Guinea worm parasite presence, whereas village membership in a spatial infection hotspot is largely determined by location and climate. This study provides new insight into the landscape-scale epidemiology of a debilitating parasite and can be used to more effectively target ongoing research and possibly eradication and control efforts., Competing Interests: The authors have declared that no competing interests exist.

Study Question: Can reduced representation genome sequencing offer an alternative to single nucleotide polymorphism (SNP) arrays as a generic and genome-wide approach for comprehensive preimplantation genetic testing for monogenic disorders (PGT-M), aneuploidy (PGT-A) and structural rearrangements (PGT-SR) in human embryo biopsy samples?, Summary Answer: Reduced representation genome sequencing, with OnePGT, offers a generic, next-generation sequencing-based approach for automated haplotyping and copy-number assessment, both combined or independently, in human single blastomere and trophectoderm samples., What Is Known Already: Genome-wide haplotyping strategies, such as karyomapping and haplarithmisis, have paved the way for comprehensive PGT, i.e. leveraging PGT-M, PGT-A and PGT-SR in a single workflow. These methods are based upon SNP array technology., Study Design, Size, Duration: This multi-centre verification study evaluated the concordance of PGT results for a total of 225 embryos, including 189 originally tested for a monogenic disorder and 36 tested for a translocation. Concordance for whole chromosome aneuploidies was also evaluated where whole genome copy-number reference data were available. Data analysts were kept blind to the results from the reference PGT method., Participants/materials, Setting, Methods: Leftover blastomere/trophectoderm whole genome amplified (WGA) material was used, or secondary trophectoderm biopsies were WGA. A reduced representation library from WGA DNA together with bulk DNA from phasing references was processed across two study sites with the Agilent OnePGT solution. Libraries were sequenced on an Illumina NextSeq500 system, and data were analysed with Agilent Alissa OnePGT software. The embedded PGT-M pipeline utilises the principles of haplarithmisis to deduce haplotype inheritance whereas both the PGT-A and PGT-SR pipelines are based upon read-count analysis in order to evaluate embryonic ploidy. Concordance analysis was performed for both analysis strategies against the reference PGT method., Main Results and the Role of Chance: PGT-M analysis was performed on 189 samples. For nine samples, the data quality was too poor to analyse further, and for 20 samples, no result could be obtained mainly due to biological limitations of the haplotyping approach, such as co-localisation of meiotic crossover events and nullisomy for the chromosome of interest. For the remaining 160 samples, 100% concordance was obtained between OnePGT and the reference PGT-M method. Equally for PGT-SR, 100% concordance for all 36 embryos tested was demonstrated. Moreover, with embryos originally analysed for PGT-M or PGT-SR for which genome-wide copy-number reference data were available, 100% concordance was shown for whole chromosome copy-number calls (PGT-A)., Limitations, Reasons for Caution: Inherent to haplotyping methodologies, processing of additional family members is still required. Biological limitations caused inconclusive results in 10% of cases., Wider Implications of the Findings: Employment of OnePGT for PGT-M, PGT-SR, PGT-A or combined as comprehensive PGT offers a scalable platform, which is inherently generic and thereby, eliminates the need for family-specific design and optimisation. It can be considered as both an improvement and complement to the current methodologies for PGT., Study Funding/competing Interest(s): Agilent Technologies, the KU Leuven (C1/018 to J.R.V. and T.V.) and the Horizon 2020 WIDENLIFE (692065 to J.R.V. and T.V). H.M. is supported by the Research Foundation Flanders (FWO, 11A7119N). M.Z.E, J.R.V. and T.V. are co-inventors on patent applications: ZL910050-PCT/EP2011/060211- WO/2011/157846 'Methods for haplotyping single cells' and ZL913096-PCT/EP2014/068315 'Haplotyping and copy-number typing using polymorphic variant allelic frequencies'. T.V. and J.R.V. are co-inventors on patent application: ZL912076-PCT/EP2013/070858 'High-throughput genotyping by sequencing'. Haplarithmisis ('Haplotyping and copy-number typing using polymorphic variant allelic frequencies') has been licensed to Agilent Technologies. The following patents are pending for OnePGT: US2016275239, AU2014345516, CA2928013, CN105874081, EP3066213 and WO2015067796. OnePGT is a registered trademark. D.L., J.T. and R.L.R. report personal fees during the conduct of the study and outside the submitted work from Agilent Technologies. S.H. and K.O.F. report personal fees and other during the conduct of the study and outside the submitted work from Agilent Technologies. J.A. reports personal fees and other during the conduct of the study from Agilent Technologies and personal fees from Agilent Technologies and UZ Leuven outside the submitted work. B.D. reports grants from IWT/VLAIO, personal fees during the conduct of the study from Agilent Technologies and personal fees and other outside the submitted work from Agilent Technologies. In addition, B.D. has a patent 20160275239 - Genetic Analysis Method pending. The remaining authors have no conflicts of interest., (© The Author(s) 2019. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Canonical Notch signaling involves Notch receptor activation via interaction with cell surface bound Notch ligand. Recent findings also indicate that Notch signaling may be modulated by cross-talk with other signaling mechanisms. The ECM protein MAGP2 was previously shown to regulate Notch in a cell type dependent manner, although the molecular details of this interaction have not been dissected. Here, we report that MAGP2 cell type specific control of Notch is independent of individual Notch receptor-ligand combinations but dependent on interaction with RGD binding integrins. Overexpressed MAGP2 was found to suppress transcriptional activity from the Notch responsive Hes1 promoter activity in endothelial cells, while overexpression of a RGD→RGE MAGP2 mutant increased Notch signaling in the same cell type. This effect was not unique to MAGP2 since the RGD domain of the ECM protein EGFL7 was also found to be an important modulator of Hes1 promoter activity. Independently of MAGP2 or EGFL7, inhibition of RGD-binding integrins with soluble RGD peptides also increased accumulation of active N1ICD fragments and Notch responsive promoter activity independently of changes in Notch1, Jag1, or Dll4 expression. Finally, β1 or β3 integrin blocking antibodies also enhanced Notch signaling. Collectively, these results answer the question of how MAGP2 controls cell type dependent Notch signaling, but more importantly uncover a new mechanism to understand how extracellular matrices and cellular environments impact Notch signaling., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Staphylococcus aureus bacteremia cases are complicated by bacterial persistence and treatment failure despite the confirmed in vitro susceptibility of the infecting strain to administered antibiotics. A high incidence of methicillin-resistant S. aureus (MRSA) bacteremia cases are classified as persistent and are associated with poorer patient outcomes. It is still unclear how S. aureus evades the host immune system and resists antibiotic treatment for the prolonged duration of a persistent infection. In this study, the genetic changes and associated phenotypic traits specific to S. aureus persistent bacteremia were identified by comparing temporally dispersed isolates from persistent infections (persistent isolates) originating from two independent persistent S. aureus bacteremia cases with the initial infection isolates and with three resolved S. aureus bacteremia isolates from the same genetic background. Several novel traits were associated specifically with both independent sets of persistent S. aureus isolates compared to both the initial isolates and the isolates from resolved infections (resolved isolates). These traits included (i) increased growth under nutrient-poor conditions; (ii) increased tolerance of iron toxicity; (iii) higher expression of cell surface proteins involved in immune evasion and stress responses; and (iv) attenuated virulence in a Galleria mellonella larva infection model that was not associated with small-colony variation or metabolic dormancy such as had been seen previously. Whole-genome sequence analysis identified different single nucleotide mutations within the mprF genes of all the isolates with the adaptive persistence traits from both independent cases. Overall, our data indicate a novel role for MprF function during development of S. aureus persistence by increasing bacterial fitness and immune evasion., (Copyright © 2015 Richards et al.)

Phase variation of surface structures occurs in diverse bacterial species due to stochastic, high frequency, reversible mutations. Multiple genes of Campylobacter jejuni are subject to phase variable gene expression due to mutations in polyC/G tracts. A modal length of nine repeats was detected for polyC/G tracts within C. jejuni genomes. Switching rates for these tracts were measured using chromosomally-located reporter constructs and high rates were observed for cj1139 (G8) and cj0031 (G9). Alteration of the cj1139 tract from G8 to G11 increased mutability 10-fold and changed the mutational pattern from predominantly insertions to mainly deletions. Using a multiplex PCR, major changes were detected in 'on/off' status for some phase variable genes during passage of C. jejuni in chickens. Utilization of observed switching rates in a stochastic, theoretical model of phase variation demonstrated links between mutability and genetic diversity but could not replicate observed population diversity. We propose that modal repeat numbers have evolved in C. jejuni genomes due to molecular drivers associated with the mutational patterns of these polyC/G repeats, rather than by selection for particular switching rates, and that factors other than mutational drift are responsible for generating genetic diversity during host colonization by this bacterial pathogen.

Major depressive disorder (MDD) is a common, clinically heterogeneous disorder often found comorbid with other disorders. We studied recurrent, early-onset MDD (MDD-RE) and anxiety disorders in combination to define powerful phenotypes for genetic study. We used 87 large, extended Utah pedigrees to investigate linkage to 3 phenotypes: "MDD-RE;" "MDD-RE or anxiety;" and "MDD-RE and anxiety;" where in the latter definition the disorders must appear comorbid within an individual. Pedigrees ranged in size from 2 to 6 generations and contained 3 to 42 individuals affected with MDD or anxiety (718 total). In primary analyses, we identified three regions with at least suggestive genome-wide evidence for linkage on chromosomes 3centr, 7p, and 18q. Both 7p and 18q are replication findings for related phenotypes. The best linkage evidence was for a novel locus at 3p12.3-q12.3 (LOD = 3.88, "MDD-RE or anxiety") and 18q21.33-q22.2 (LOD = 3.75, "MDD-RE and anxiety"), a well-established susceptibility locus for bipolar disorder. In our secondary sex-specific analyses, we identified two further regions of interest on chromosomes 4q and 15q. Using linked pedigrees, we localized 3centr and 18q to 9.8 and 12.2 cM, respectively, with potential for further localization with the addition of markers in specific pedigrees. Our success in replication and novel locus identification illustrates the utility of large extended pedigrees for common disorders, such as MDD. Further, it supports the hypothesis that MDD and anxiety disorders have over-lapping genetic etiologies and suggests that comorbid diagnoses may be useful in defining more genetically homogeneous forms of MDD for linkage mapping., (Copyright 2005 Wiley-Liss, Inc.)

Protective or therapeutic immunity against HIV infection is currently believed to require both antibody and CTL responses against the envelope protein. In the present study, the adjuvant activity of a unique oil-in-water emulsion, in which liposomes containing lipid A (LA) and encapsulated antigen served as the emulsifying agent, was examined in mice using oligomeric gp140 (ogp140) derived from the HIV-1 envelope as the antigen. Emulsions rendered either highly stable or unstable by altering the ratio of liposomes to oil were used to examine the effect of stability of the emulsion on adjuvant activity. Stable and unstable emulsions had similar potencies for inducing both IgG antibodies to ogp140 and antigen-specific T-lymphocyte proliferation. Stable emulsions, but not unstable emulsions, induced antigen-specific CTL responses, possibly because of the depot effect of the stable emulsions. Furthermore, stable emulsions induced lower IgG2a/IgG1 ratios than the unstable emulsions. We conclude that stable liposomal oil-in-water emulsions provide an effective means of obtaining both antibody and CTL responses against an HIV envelope antigen., (Copyright 2004 Australasian Society for Immunology Inc.)

Major depression disorder is a common psychiatric disease with a major economic impact on society. In many cases, no effective treatment is available. The etiology of major depression is complex, but it is clear that the disease is, to a large extent, determined genetically, especially among individuals with a familial history of major depression, presumably through the involvement of multiple predisposition genes in addition to an environmental component. As a first step toward identification of chromosomal loci contributing to genetic predisposition to major depression, we have conducted a genomewide scan by using 628 microsatellite markers on 1,890 individuals from 110 Utah pedigrees with a strong family history of major depression. We identified significant linkage to major depression in males at marker D12S1300 (multipoint heterogeneity LOD score 4.6; P=.00003 after adjustment for multiple testing). With additional markers, the linkage evidence became highly significant, with the multipoint heterogeneity LOD score at marker D12S1706 increasing to 6.1 (P=.0000007 after adjustment for multiple testing). This study confirms the presence of one or more genes involved in psychiatric diseases on the q arm of chromosome 12 and provides strong evidence for the existence of a sex-specific predisposition gene to major depression at 12q22-q23.2.

1. Prolonged exposure of the extremities to cold insufficient to cause tissue freezing produces a well-defined syndrome. 'Immersion foot' is one of the descriptive but inaccurate terms applied to this syndrome. The clinical features, aetiology, pathology, prevention, and treatment of immersion foot are considered in detail. A discussion on pathogenesis is also included. 2. In the natural history of a typical case of immersion foot there are four stages: the period of exposure and the pre-hyperaemic, hyperaemic, and post-hyperaemic stages. 3. During exposure and immediately after rescue the feet are cold, numb, swollen, and pulseless. Intense vasoconstriction sufficient to arrest blood-flow is believed to be the predominant factor during this phase. 4. This is followed by a period of intense hyperaemia, increased swelling, and severe pain. Hyperaemia is due to the release in chilled and ischaemic tissues of relatively stable vasodilator metabolites; pain may be the result of relative anoxia of sensory nerve-endings. 5. Within 7-10 days of rescue the intense hyperaemia and swelling subside and pain diminishes in intensity. A lesser degree of hyperaemia may persist for several weeks. Objective disturbances of sensation and sweating and muscular atrophy and paralysis now become apparent. These findings are correlated with damage to the peripheral nerves. 6. After several weeks the feet become cold-sensitive; when exposed to low temperature they cool abnormally and may remain cold for several hours. Hyperhidrosis frequently accompanies this cold-sensitivity. The factors responsible for these phenomena are incompletely understood; several possible explanations are considered. 7. Severe cases may develop blisters and gangrene. The latter is usually superficial and massive loss of tissue is rare. 8. The hands may be affected but seldom as severely as the feet. The essential features of immersion hand are the same as those of immersion foot. 9. Prognosis depends upon severity. The extent of anaesthesia at 7-10 days has been found a useful guide to the latter, and has formed a basis of a method of classification. 10. Rapid warming of chilled tissues is condemned. Cold therapy is of value for the relief of pain in the hyperaemic stage, but should not be used in the pre-hyperaemic stage. Sympathectomy and other measures designed to increase the peripheral circulation should not be employed immediately after rescue, but may have a place in the treatment of the later cold-sensitive state. This paper records the results of observations made during 1941 and 1942. Delay in publication has been necessary because of war-time difficulties of maintaining contact between authors. In this respect we have received much help from Surgeon Rear-Admiral J. W. McNee. We wish to thank Professors R. S. Aitken and J. R. Learmonth for much helpful advice during the preparation of the paper. The charts have been prepared by the technical staff of the Wilkie Surgical Research Laboratory, University of Edinburgh. During the period of the study, one of us (R. L. R.) was in receipt of a personal grant from the Medical Research Council.

The bis-molybdopterin enzyme dimethylsulfoxide reductase (DMSOR) from Rhodobacter capsulatus catalyzes the conversion of dimethyl sulfoxide (DMSO) to dimethyl sulfide (DMS), reversibly, in the presence of suitable e(-)-donors or e(-)-acceptors. The catalytically significant intermediate formed by reaction of DMSOR with DMS ('the DMS species') and a damaged enzyme form derived by reaction of the latter with O(2) (DMS-modified enzyme, DMSOR(mod)D) have been investigated. Evidence is presented that Mo in the DMS species is not, as widely assumed, Mo(IV). Formation of the DMS species is reversed on removing DMS or by addition of an excess of DMSO. Equilibrium constants for the competing reactions of DMS and DMSO with the oxidized enzyme (K(d) = 0.07 +/- 0.01 and 21 +/- 5 mM, respectively) that control these processes indicate formation of the DMS species occurs at a redox potential that is 80 mV higher than that required, according to the literature, for reduction of Mo(VI) to Mo(IV) in the free enzyme. Specificity studies show that with dimethyl selenide, DMSOR yields a species analogous to the DMS species but with the 550 nm peak blue-shifted by 27 nm. It is concluded from published redox potential data that this band is due to metal-to-ligand charge transfer from Mo(V) to the chalcogenide. Since the DMS species gives no EPR signal in the normal or parallel mode, a free radical is presumed to be in close proximity to the metal, most likely on the S. The species is thus formulated as Mo(V)-O-S(*)Me(2). Existing X-ray crystallographic and Raman data are consistent with this structure. Furthermore, 1e(-) oxidation of the DMS species with phenazine ethosulfate yields a Mo(V) form without an -OH ligand, since its EPR signal shows no proton splittings. This form presumably arises via dissociation of DMSO. The structure of DMSOR(mod)D has been determined by X-ray crystallography. All four thiolate ligands and Ogamma of serine-147 remain coordinated to Mo, but there are no terminal oxygen ligands and Mo is Mo(VI). Thus, it is a dead-end species, neither oxo group acceptance nor e(-)-donation being possible. O(2)-dependent formation of DMSOR(mod)D represents noncatalytic breakdown of the DMS species by a pathway alternative to that in turnover, with oxidation to Mo(VI) presumably preceding product release. Steps in the forward and backward catalytic cycles are discussed in relation to earlier stopped-flow data. The finding that in the back-assay the Mo(IV) state may at least in part be by-passed via two successive 1e(-) reactions of the DMS species with the e(-)-acceptor, may have implications in relation to the existence of separate molybdopterin enzymes catalyzing DMSO reduction and DMS oxidation, respectively.

Vanadium(III) and vanadium(V) complexes derived from the tris(2-thiolatoethyl)amine ligand [(NS3)3-] and the bis(2-thiolatoethyl)ether ligand [(OS2)2-] have been synthesized with the aim of investigating the potential of these vanadium sites to bind dinitrogen and activate its reduction. Evidence is presented for the transient existence of (V(NS3)(N2)V(NS3), and a series of mononuclear complexes containing hydrazine, hydrazide, imide, ammine, organic cyanide, and isocyanide ligands has been prepared and the chemistry of these complexes investigated. [V(NS3)O] (1) reacts with an excess of N2H4 to give, probably via the intermediates (V(NS3)(NNH2) (2a) and (V(NS3)(N2)V(NS3) (3), the V(III) adduct [V(NS3)(N2H4)] (4). If 1 is treated with 0.5 mol of N2H4, 0.5 mol of N2 is evolved and green, insoluble [(V(NS3))n] (5) results. Compound 4 is converted by disproportionation to [V(NS3)(NH3)] (6), but 4 does not act as a catalyst for disproportionation of N2H4 nor does it act as a catalyst for its reduction by Zn/HOC6H3Pri2-2,6. Compound 1 reacts with NR1(2)NR2(2) (R1 = H or SiMe3; R2(2) = Me2, MePh, or HPh) to give the hydrazide complexes [V(NS3)(NNR2(2)] (R2(2) = Me2, 2b; R2(2) = MePh, 2c; R2(2) = HPh, 2d), which are not protonated by anhydrous HBr nor are they reduced by Zn/HOC6H3Pri2-2,6. Compound 2b can also be prepared by reaction of [V(NNMe2)(dipp)3] (dipp = OC6H3Pri2-2,6) with NS3H3. N2H4 is displaced quantitatively from 4 by anions to give the salts [NR3(4)][V(NS3)X] (X = Cl, R3 = Et, 7a; X = Cl, R3 = Ph, 7b; X = Br, R3 = Et, 7c; X = N3, R3 = Bu(n), 7d; X = N3, R3 = Et, 7e; X = CN, R3 = Et, 7f). Compound 6 loses NH3 thermally to give 5, which can also be prepared from [VCl3(THF)3] and NS3H3/LiBun. Displacement of NH3 from 6 by ligands L gives the adducts [V(NS3)(L)] (L = MeCN, nu CN 2264 cm-1, 8a; L = ButNC, nu NC 2173 cm-1, 8b; L = C6H11NC, nu NC 2173 cm-1, 8c). Reaction of 4 with N3SiMe3 gives [V(NS3)(NSiMe3)] (9), which is converted to [V(NS3)(NH)] (10) by hydrolysis and to [V(NS3)(NCPh3)] (11) by reaction with ClCPh3. Compound 10 is converted into 1 by [NMe4]OH and to [V(NS3)NLi(THF)2] (12) by LiNPri in THF. A further range of imido complexes [V(NS3)(NR4)] (R4 = C6H4Y-4 where Y = H (13a), OMe (13b), Me (13c), Cl (13d), Br (13e), NO2 (13f); R4 = C6H4Y-3, where Y = OMe (13g); Cl (13h); R4 = C6H3Y2-3,4, where Y = Me (13i); Cl (13j); R4 = C6H11 (13k)) has been prepared by reaction of 1 with R4NCO. The precursor complex [V(OS2)O(dipp)] (14) [OS2(2-) = O(CH2CH2S)2(2-)] has been prepared from [VO(OPri)3], Hdipp, and OS2H2. It reacts with NH2NMe2 to give [V(OS2)(NNMe2)(dipp)] (15) and with N3SiMe3 to give [V(OS2)(NSiMe3)(dipp)] (16). A second oxide precursor, formulated as [V(OS2)1.5O] (17), has also been obtained, and it reacts with SiMe3NHNMe2 to give [V(OS2)(NNMe2)(OSiMe3)] (18). The X-ray crystal structures of the complexes 2b, 2c, 4, 6, 7a, 8a, 9, 10, 13d, 14, 15, 16, and 18 have been determined, and the 51V NMR and other spectroscopic parameters of the complexes are discussed in terms of electronic effects.

Encapsulation of soluble protein antigens in liposomes was previously shown to result in processing of antigen via the major histocompatibility complex class I pathway, as evidenced by costaining of the trans-Golgi region of murine bone marrow-derived macrophages (BMs) by fluorophore-labeled liposomal antigen and by a trans-Golgi-specific fluorescent lipid. Evidence is presented here that free or liposome-encapsulated RTS,S, a particulate malaria antigen consisting of hepatitis B particles coexpressed with epitopes from the Plasmodium falciparum circumsporozoite protein, also was localized in the trans-Golgi after incubation with BMs, suggesting processing by the class I pathway. An in vivo cytotoxic T-lymphocyte (CTL) response was detected, however, only after immunization with RTS,S encapsulated in liposomes containing lipid A and not after immunization with free RTS,S or with RTS,S encapsulated in liposomes lacking lipid A. Therefore, intracellular delivery of antigen containing CTL epitopes to the Golgi of BMs does not necessarily result in a CTL response in vivo unless an additional adjuvant, such as liposomes containing lipid A, is utilized. Encapsulation of RTS,S in liposomes containing monophosphoryl lipid A (MPL) resulted in a dose-dependent enhancement of the NANP-specific immunoglobulin G (IgG) antibody response compared to that of free RTS,S. The IgG1 and IgG2a subclasses predominated after immunization with RTS,S encapsulated in liposomes containing MPL. These results demonstrate that encapsulation of a lipid-containing particulate antigen, such as RTS, S, in liposomes containing lipid A can enhance both humoral and cellular immune responses.

Only low antibody levels were obtained from vaccinating human volunteers with single-chain peptide from the Plasmodium falciparum circumsporozoite protein (PfCSP). This resulted in modest protection against sporozoite challenge. In addition, HLA restriction limits the probability of synthesis of a vaccine effective for a diverse population. We report immunization studies with a multiple antigen peptide (MAP) system consisting of multiple copies of a B-cell epitope from the central repeat region of the PfCSP in combination with a universal T-cell epitope, the P2P30 portion of tetanus toxin. This MAP4(NANP)6P2P30 vaccine was highly immunogenic in four different strains of mice when used with various safe and nontoxic adjuvants. When this MAP vaccine was encapsulated in liposomes with lipid A and adsorbed to aluminium hydroxide and given three times at 4-week intervals, the resultant antibody prevented 100% of sporozoites from invading and developing into liver stage infection. This high degree of immunogenicity of MAP4(NANP)6P2P30 vaccine formulated in liposomes, lipid A and aluminum hydroxide provides the foundation for consideration of human trials with this formulation.

Mice vaccinated with a recombinant protein containing the two EGF-like modules of Plasmodium yoelii merozoite surface protein-1 in liposomes or combined with the formulations SBAS2.1 and SBAS2, were protected against a lethal malaria infection. The protection achieved with these adjuvants developed for clinical use was as good as or better than that achieved with Freund's adjuvant. A parasite-specific response was needed for protection. Analysis of the immunoglobulin sub-class response showed that MSP-1-specific IgG1, and to a lesser extent IgG2a and IgG2b, were induced, suggesting that these antibodies were important for protection. Mice passively immunized with serum or purified IgG from vaccinated mice had delayed onset of parasitemia and were able to control the infection.

Various formulations of the Plasmodium falciparum merozoite surface antigen, MSA-2, were made and tested in animals in order to select one for use in human vaccine trials. Recombinant constructs representing both major allelic forms of MSA-2 were formulated with a range of adjuvants and used to immunize rabbits, mice and sheep. After immunization, antibody responses obtained with the most potent adjuvants were at least tenfold greater than responses obtained with the least potent adjuvant Alhydrogel, which was used as the reference standard, although its lower potency indicated against its further use in clinical trials. Based on broadly similar results obtained with the three animal species, several adjuvants, including the water-in-oil adjuvant Montanide ISA 720, the oil-in-water adjuvant SAF-1, and liposomes containing lipid A formulated with Alhydrogel were demonstrated to be potent and potentially suitable for the clinical evaluation of MSA-2 as a candidate malaria vaccine antigen. Of these, ISA 720 was selected for further trial.

Protein and peptide antigens frequently are only slightly immunogenic when utilized alone in vaccines. Formulation of these antigens in a carrier vehicle, particularly when an adjuvant is included, often results in markedly enhanced immune responses. Encapsulation of peptide and protein antigens in liposomes generally results in a relatively slight enhancement of antibody production compared with that observed with the antigen alone. However, when lipid A is included in the liposomes, immunogenicity is markedly increased compared both with antigen alone and with antigen encapsulated in liposomes lacking lipid A. The enhancement of the immune response caused by lipid A is dependent on the liposomal lipid A dose. Aluminum salts, such as aluminum hydroxide and aluminum phosphate, act as adjuvants for some antigens and are used in a variety of human vaccines. When liposomes containing encapsulated protein or peptide antigens were adsorbed with aluminum hydroxide, an enhancement of the antibody response was observed with some antigens, whereas with other antigens the presence of aluminum hydroxide either had no effect or resulted in a diminished antibody response. Immunogenicity of protein and peptide antigens can be enhanced by formulation in liposomes containing lipid A and, depending on the antigen, can be enhanced further by adsorption of the liposomal antigen formulation with aluminum salts.

Merozoite surface protein 1 (MSP-1) of Plasmodium falciparum is an antimalarial vaccine candidate. The highly conserved 19-kDa C-terminal processing fragment of MSP-1 (MSP-1(19)) is of particular interest since it contains epitopes recognized by monoclonal antibodies which inhibit the invasion of erythrocytes in vitro. The presence of naturally acquired anti-MSP-1(19) antibodies in individuals exposed to malaria has been correlated with reduced morbidity, and immunization with an equivalent recombinant P. yoelii antigen induces substantial protection against this parasite in mice. We have expressed P. falciparum MSP-1(19) in Escherichia coli as a correctly folded protein and immunized Aotus nancymai monkeys by using the protein incorporated into liposomes and adsorbed to alum. After vaccination, the sera from these animals contained anti-MSP-1(19) antibodies, some of which competed for binding to MSP-1(19) with monoclonal antibodies that inhibit parasite invasion of erythrocytes in vitro. However, after challenge with either a homologous or a heterologous strain of parasite, all animals became parasitemic and required treatment. The immunization did not induce protection in this animal model.

Seventeen malaria-naive volunteers received a recombinant Plasmodium falciparum vaccine (RLF) containing the carboxy- and the amino-terminal of the circumsporozoite protein (CSP) antigen without the central tetrapeptide repeats. The vaccine was formulated in liposomes with either a low or high dose of 3-deacylated monophosphoryl lipid A (MPL) and administered with alum by intramuscular injection. Both formulations were well tolerated and immunogenic. MPL increased sporozoite antibody titers measured by ELISA, Western blot, and immunofluorescence assay. One high-dose MPL vaccine formulation recipient developed a CSP-specific cytotoxic T lymphocyte response. After homologous sporozoite challenge, immunized volunteers developed patent malaria. There was no correlation between prepatent period and antibody titers to the amino- or carboxy-terminal. The absence of delay in patency argues against inclusion of the amino-terminal in future vaccines. A significant cytotoxic T lymphocyte response may have been suppressed by the inclusion of alum as an adjuvant.

The reaction mechanism of the molybdoenzyme xanthine oxidase has been further investigated by 13C and 17O ENDOR of molybdenum(V) species and by kinetic studies of exchange of oxygen isotopes. Three EPR signal-giving species were studied: (i) Very Rapid, a transient intermediate in substrate turnover, (ii) Inhibited, the product of an inhibitory side reaction with aldehyde substrates, and (iii) Alloxanthine, a species formed by reaction of reduced enzyme with the inhibitor, alloxanthine. The Very Rapid signal was developed either with [8-13C]xanthine or with 2-oxo-6-methylpurine using enzyme equilibrated with [17O]H2O. The Inhibited signal was developed with 2H13C2HO and the Alloxanthine signal by using [17O]H2O. Estimates of Mo-C distances were made, from the anisotropic components of the 13C-couplings, by corrected dipolar coupling calculations and by back-calculation from assumed possible structures. Estimated distances in the Inhibited and Very Rapid species were about 1.9 and less than 2.4 A, respectively. A Mo-C bond in the Inhibited species is very strongly suggested, presumably associated with side-on bonding to molybdenum of the carbonyl of the aldehyde substrate. For the Very Rapid species, a Mo-C bond is highly likely. Coupling from a strongly coupled 17O, not in the form of an oxo group, and no coupling from other oxygens was detected in the Very Rapid species. No coupled oxygens were detected in the Alloxanthine species. That the coupled oxygen of the Very Rapid species is the one that appears in the product uric acid molecule was confirmed by new kinetic data. It is concluded that this oxygen of the Very Rapid species does not, as frequently assumed, originate from the oxo group of the oxidized enzyme. A new turnover mechanism is proposed, not involving direct participation of the oxo ligand group, and based on that of Coucouvanis et al. [Coucouvanis, D., Toupadakis, A., Lane, J. D., Koo, S. M., Kim, C. G., Hadjikyriacou, A. (1991) J. Am. Chem. Soc. 113, 5271-5282]. It involves formal addition of the elements of the substrate (e.g., xanthine) across the Mo = S double bond, to give a Mo(VI) species. This is followed by attack of a "buried" water molecule (in the vicinity of molybdenum and perhaps a ligand of it) on the bound substrate carbon, to give an intermediate that on intramolecular one-electron oxidation gives the Very Rapid species. The latter, in keeping with the 13C, 17O, and 33S couplings, is presumed to have the 8-CO group of the uric acid product molecule bonded side-on to molybdenum, with the sulfido molybdenum ligand retained, as in the oxidized enzyme.

The IgG subclass responses to antigens incorporated in liposomes containing lipid A were investigated using a synthetic malarial antigen (SPf66) and cholera toxin (CT). The antigen-specific IgG subclass response was determined in BALB/c mice immunized with either: (a) SPf66 encapsulated in liposomes containing lipid A, (b) CT bound to the surface of liposomes containing lipid A, or (c) both encapsulated SPf66 and surface-bound CT in the same liposomes. In each case the antibodies to SPf66, CT and lipid A demonstrated an IgG2a predominance. Liposomes containing lipid A not only increased the magnitude of the antibody response to liposomal antigens but elicited predominantly IgG2a subclass antibodies as well.

A liposome vaccine formulation that has been successfully used in both animal immunization studies and clinical trials is described. Issues concerning the choice of components for the liposomal vaccine formulation are discussed, especially with respect to the lipid components and the adjuvant. A procedure is described for manufacturing liposomal vaccines using Good Manufacturing Practices as promulgated by the U.S. Food and Drug Administration. Quality control testing for clinical use is described, with particular emphasis on aspects relevant to liposomes. Utilization issues are discussed, including injection volumes, antigen and adjuvant doses, and routes of administration.

FeMoco, a low-M(r) metal cluster of probable composition Fe7MoS9 complexed with homocitrate, has been extracted with N-methylformamide from the MoFe protein of the nitrogenase enzyme from Klebsiella pneumoniae. The binding of cyanide and thiols to the FeMoco cluster in its paramagnetic S = 3/2 oxidation level has been studied by low-temperature e.p.r. and magnetic-circular-dichroism (m.c.d.) spectroscopies. Cyanide binds to isolated FeMoco at more than one site, and causes changes in the g values form g = 4.6, 3.2, 2.0 to g = 4.29, 3.82, 2.02 E.p.r. competition studies indicate that one cyanide can be displaced by thiolate from one type of site. The form of the low-temperature m.c.d. spectrum is little changed by ligand binding, thus the basic cluster structure remains intact. However, when benzenethiol is bound, a new intense band (lambda 387 nm) is observed, indicating the generation of an increased ligand-to-cluster charge-transfer interaction.

Plasmodium circumsporozoite (CS) protein-induced antibody and T-cell responses are considered to be important in protective immunity. Since the key repeat determinant of the CS protein may actually restrict the recognition of other potential T- and B-cell sites, a modified Plasmodium falciparum CS protein lacking the central repeat region, RLF, was expressed in Escherichia coli. On purification, RLF was encapsulated into liposomes [L(RLF)] and used for the in vivo induction of cytolytic T lymphocytes (CTL) and antibodies. Immunization of B10.Br (H-2k) mice with L(RLF), but not with RLF, induced CD8+ CTL specific for the P. falciparum CS protein CTL epitope, amino acid residues 368-390. Anti-L(RLF) serum reacted with antigens on intact sporozoites and inhibited sporozoite invasion of hepatoma cells. Antibody specificity studies in New Zealand White rabbits revealed new B-cell sites localized in amino acid residues 84-94, 91-99, 97-106 and 367-375. Although the mechanisms by which liposomes enhance cellular and humoral immune responses remain unknown, liposome-formulated vaccines have been well tolerated in humans; hence, their use in vaccines, when efficacy depends on antibody and CTL responses, may be broadly applicable.

Adjuvant research has improved the ability of biotechnology to generate novel vaccines. Numerous strategies for enhancing the immunogenicity of synthetic peptides and proteins have been identified. This overview focuses on adjuvant development and vaccine delivery systems that provide new tools for amplifying the effectiveness of ongoing malaria and AIDS vaccine development programs. In addition, some of the complex challenges and issues that have become associated with the delivery of modern vaccines in man are outlined. As adjuvant research continues to open new opportunities in vaccine development, there is renewed expectation that further generations of safe and potent vaccines will be possible against a broad spectrum of infectious agents and cancer.

This study describes the safety and immunogenicity of a liposome-based vaccine injected into human subjects. Thirty healthy adult male volunteers were immunized with a liposome-encapsulated recombinant protein (R32NS181) containing epitopes from the repeat region of the circumsporozoite protein of Plasmodium falciparum. This antigen had previously been found to be poorly immunogenic in humans when it was adsorbed with Al(OH)3. In the present study, R32NS181 was encapsulated in liposomes containing monophosphoryl lipid A that were subsequently adsorbed to Al(OH)3. Increasing doses of liposomes containing antigen and monophosphoryl lipid A were used, but the liposomes were always adsorbed to the same dose of Al(OH)3. R32-specific serum IgG antibody responses to liposome-encapsulated R32NS181 were much higher than levels attained previously in humans with R32NS181 adsorbed to Al(OH)3. Geometric mean specific IgG levels after three doses ranged from 14 to 33 micrograms/ml. Sera from volunteers receiving the two highest doses inhibited P. falciparum sporozoite invasion of cultured hepatoma cells by an average of 92%, a result that was again superior to previously reported vaccines. Moderate but acceptable transient local reactogenicity was noted at high doses of the vaccine formulation, but little or no systemic toxicity was seen despite liposomal monophosphoryl lipid A doses up to 2200 micrograms. We conclude that encapsulation of poorly immunogenic circumsporozoite protein repeat peptides in monophosphoryl lipid A-containing liposomes is a successful adjuvant strategy in humans for inducing high levels of specific antibody production.

The MMPI was administered during the patient-perceived best time of the menstrual cycle and during the patient-perceived worst time of the cycle in order to examine the stability of MMPI profile configurations. Subjects were 214 women who were referred to two metropolitan outpatient premenstrual syndrome (PMS) clinics for moderate to severe premenstrual complaints. This sample was selected from 1,849 intake files after screening by strict selection criteria for PMS. The results indicate that there are wide fluctuations in profile patterns between the best and worst times of the menstrual cycle for a large number of patients. Caution in using the MMPI is strongly advised.

An unmatched case control study of molar pregnancy was carried out at this hospital between 1978 and 1987 to investigate the influence of maternal age and ethnic group on the incidence of complete and partial hydatidiform mole. The age specific incidence of complete mole was minimal between the ages of 30 and 34 years (relative risk 1), showed a minor peak in teenagers (relative risk 3.1, 95% confidence interval 6.5-1.4), and a major peak in those of 35 years and over. Between 35 and 39 years the relative risk was 2.5 (95% CI 6.2-1.0) and at 40 years or more the relative risk was 9.8 (95% CI 28.9-3.3). No age group showed a significantly increased risk of partial mole. The women of Abu Dhabi had increased risks of both forms of molar pregnancy relative to women in Nottingham, England (relative risk 1): the risk of complete mole was increased threefold (95% CI 4.2-2.2) and that of partial mole twofold (95% CI 4.0-1.2). The increased risk of complete mole was greatest in Gulf Arabs (mainly Omanis and Yemenis) who had a sixfold increase in crude relative risk (95% CI 10.7-3.5). The increased risks of complete mole associated with maternal ethnic group remained after adjustment for maternal age distribution.

Liposomes containing lipid A have been developed as adjuvants for inducing humoral immunity to synthetic antigens containing repeat sequence epitopes from the circumsporozoite protein of Plasmodium falciparum. Preclinical studies demonstrated that liposomes containing lipid A and encapsulated antigen could overcome immunosuppression observed with antigen alone. When liposomes containing lipid A were adsorbed with aluminum hydroxide (alum), further stimulation of humoral immunity against encapsulated antigen was observed in animals. In the presence of huge doses of liposomal lipid A pyrogenicity was not observed and adjuvant activity was enhanced. A phase I human clinical trial has been initiated utilizing a vaccine containing a synthetic recombinant antigen and monophosphoryl lipid A in liposomes and nonliposomal alum as a further adjuvant. Preliminary results confirm that the vaccine lacks significant acute toxicity in humans and causes very strong specific humoral immunity against the appropriate epitopes of the target antigen.

Maximal release of trapped liposomal glucose, in the presence of saturating amounts of liposomal antigen (galactocerebroside), antiserum (anti-galactocerebroside), and complement, was dependent on temperature. At lower temperatures (20--25 degrees C), maximal glucose release was inversely related to liposomal phospholipid fatty acyl chain length (dimyristoyl phosphatidylcholine > dipalmitoyl phosphatidylcholine > distearoyl phosphatidylcholine > sphingomyelin). At higher temperatures (32--35 degrees C) a limiting plateau of glucose release, at approx. 60%, was reached, or approached, by all preparations. Sphingomyelin liposomes still released less glucose than those prepared from other phospholipids, even at 35 degrees C. The titers of antiserum and complement (ABL50/ml and CL50/ml) were dependent on temperature, and differences based on liposomal phospholipid fatty acyl chain length were observed. Analysis of antiserum and complement-dependence on temperature, and on phospholipid type, revealed that although antibody binding to galactocerebroside undoubtedly was subject to steric hindrance due to interference by surrounding phospholipids at 20--25 degrees C, steric hindrance did not play a major role in blocking antibody binding above 32 degrees C.

Hodgkin's disease is a rare cause of secondary amyloidosis. In Scotland in the period 1961 to 1974 four patients in whom these 2 conditions were associated have been identified. In one of these the presence of amyloidosis was an unexpected finding at a staging laparotomy for Hodgkin's disease. The clinical and pathological features are summarised. The development of amyloid disease is usually suspected by the finding of proteinuria, which is rarely present in uncomplicated Hodgkin's disease. A distinction is made between a nephrotic syndrome due to glomerulopathy, which is an early complication of Hodgkin's disease and improves with treatment of the primary condition, and the nephrotic syndrome due to amyloidosis which occurs late in the course of the illness and is irreversible and rapidly progressive.

The immunogenicity of a recombinant protein (R32tet32) containing sequences from the tetrapeptide repeat region of the circumsporozoite protein of Plasmodium falciparum was enhanced by encapsulation in liposomes containing lipid A and adsorption of the liposomes with alum. The toxicities and efficacies of preparations containing different types and doses of lipid A were assessed by studying pyrogenicity in rabbits and adjuvanticity in monkeys. In each case liposomal lipid A was 25-fold to 200-fold less pyrogenic than free lipid A. Monophosphoryl lipid A, whether free or in liposomes, was the least pyrogenic of the three lipid A preparations tested. High antibody levels were obtained after immunization of rhesus monkeys with a formulation consisting of alum-adsorbed liposomes in which the liposomes contained R32tet32 and a strongly pyrogenic dose of native lipid A. Excellent antibody levels were also observed in monkeys immunized with a combination of R32tet32 encapsulated in alum-adsorbed liposomes containing non-pyrogenic doses of monophosphoryl lipid A and alum. The adjuvant effect was related to the dose of the lipid A in the liposomes, and the adjuvant effect was still strongly expressed despite suppression of the pyrogenic effect of lipid A. Antibody levels were considerably lower in monkeys immunized with liposomes lacking lipid A. It was concluded that a non-pyrogenic formulation of alum-adsorbed liposomes, in which the liposomes contained both lipid A and an encapsulated synthetic sporozoite antigen, shows considerable promise for inducing high titres of antibodies to sporozoites.

An age-old belief links creativity with psychopathology. The present paper examines the degree of scientific support for this belief and proposes a scheme for interpretation of the evidence within a framework of multiple causation. First, three major theories are considered; these differ fundamentally regarding whether creative ability and/or motivation may be associated with psychopathology. Next, creativity research involving cognitive, personality, motivational, and environmental variables is examined in this theoretical context. Results do not emerge as definitive for any one type of position. It is suggested instead that the origins of creativity may be heterogeneous; separate explanations may be required for distinct S subgroups, to potentially include subgroups within traditional psychiatric diagnostic categories. Epidemiological research is then considered. Despite methodological shortcomings, this work as a whole appears to support elevated levels of psychopathology among recognized creators compared to the general population, and familial (and perhaps even genetic) patterns of creativity-psychopathology association. Affective psychosis is particularly prominent across studies although design features limit full consideration of other pathologies. Some etiological hypotheses are then indicated within the framework of a proposed, inclusive classification scheme. Finally, considerations for further research are discussed, and the potential importance of continued inquiry in this area is emphasized.