Despite extensive research and a vast literature, the diagnosis of schizophrenia remains primarily a clinical decision based upon the presence of some agreed-upon symptom complex. Laboratory studies and special testing procedures have not yet demonstrated their utility in establishing diagnosis in this syndrome. While it is easy to cite studies of diagnostic difficulty (Beck, 1962), it is also apparent that when clinicians state they are ‘certain of the diagnosis' or agree to utilize pre-established diagnostic stereotypes, the diagnostic agreement frequently achieves an 80 per cent reliability (Beck, 1962; Hordern et al., 1968). Clinicians the world over tend to identify gross symptoms in similar ways. However, they may ascribe varying significance to similar symptom complexes and may even use similar symptom constellations to arrive at different diagnoses (Saenger, 1968; Sandifer et al., 1968). There seems to be general agreement on the major symptoms found in schizophrenia (Cooper, 1967; Beck et al., 1962; Hordem et al., 1968); however, diagnostic agreement on subtypes, and on admixtures of paranoid symptoms and depression is much more difficult to achieve (Cooper, 1967; Morgan et al., 1968; Lorr and Klett, 1968; Hordem et al., 1968). The present study attempts to formalize the apparent commonality of clinical features which together establish a diagnosis of schizophrenia through the development of a valid and reliable checklist of symptoms.

Although host immunity offers the obvious benefit of reducing parasite infection, it is often traded‐off with other fitness components. We investigated whether the cost of an immune response in the yellow fever mosquito, Aedes aegypti, is modulated by the antigen that activates the melanization immune response. Thus, one of three different novel antigens were injected into the mosquito's thorax – either a glass bead, a negatively charged (C‐25) Sephadex bead, or a neutral (G‐25) Sephadex bead – and fecundity and bead melanization were observed. Glass beads are immunologically inert and were therefore used as an inoculation control. The fecundity of mosquitoes inoculated with these beads did not differ from the fecundity of mosquitoes that did not melanize negatively charged or neutral beads. The ability of A. aegypti to melanize negatively charged Sephadex beads was associated with reduced fecundity, showing a clear cost of immunity. In contrast, melanization of the neutral beads was quite strong but had no effect on fecundity. Thus, the cost of what appeared to be the same immune response – melanization of a bead – depended on the type of bead that stimulated the immune system. Such differences might help to explain variation of immune efficacy against different parasites in natural populations.

The melanization responses of field-captured Anopheles gambiae s.l. toward oocysts of the malaria parasite Plasmodium falciparum or negatively charged (C-25) Sephadex beads were determined. Only two of 431 infected mosquitoes harboured melanized oocysts. However, 90% of field-captured mosquitoes melanized C-25 Sephadex beads. The effects of age, glucose concentration and blood meal on the melanization response of an An gambiae s.s. laboratory colony toward C-25 beads were also assayed. All newly emerged females (which did not blood-feed) melanized the beads. By 4 d postemergence, there was a marked reduction in melanization response, particularly among those mosquitoes that had not blood fed. A blood meal, however, taken by 4-d-old mosquitoes increased their immune response as did high glucose concentrations in the nonblood-fed group. These data indicate that C-25 Sephadex beads can estimate the general strength of An. gambiae's immune response. However, C-25 beads do not accurately model An. gambiae's susceptibility to P falciparum oocysts in natural populations. To the best of our knowledge, this is the first report of field refractoriness in An. gambiae s.l.

Despite increasing evidence of behavioural manipulation of their vectors by pathogens, the underlying mechanisms causing infected vectors to act in ways that benefit pathogen transmission remain enigmatic in most cases. Here, 2-D DIGE coupled with MS were employed to analyse and compare the head proteome of mosquitoes (Anopheles gambiae sensu stricto (Giles)) infected with the malarial parasite (Plasmodium berghei) with that of uninfected mosquitoes. This approach detected altered levels of 12 protein spots in the head of mosquitoes infected with sporozoites. These proteins were subsequently identified using MS and functionally classified as belonging to metabolic, synaptic, molecular chaperone, signalling, and cytoskeletal groups. Our results indicate an altered energy metabolism in the head of sporozoite-infected mosquitoes. Some of the up-/down-regulated proteins identified, such as synapse-associated protein, 14-3-3 protein and calmodulin, have previously been shown to play critical roles in the CNS of both invertebrates and vertebrates. Furthermore, a heat shock response (HSP 20) and a variation of cytoarchitecture (tropomyosins) have been shown. Discovery of these proteins sheds light on potential molecular mechanisms that underlie behavioural modifications and offers new insights into the study of intimate interactions between Plasmodium and its Anopheles vector.