Definition. Oxyurinae—mouth with three small lips; cuticle with or without lateral flanges; vestibule absent; oesophagus with a posterior globular bulb containing a valvular apparatus and separated from the rest of the oesophagus by a slight constriction; excretory pore behind the oesophageal bulb; posterior extremity of the body in both sexes obliquely truncate ventrally at the level of the anus, rounded and prolonged as a long subulate tail which is provided with spines or smooth.

The trematodes described in this paper were collected by Miss Reynolds and myself from Corvus insolens, a Burmese house-crow, specimens of which contained many parasites of different species, all being minute except in two cases. They were obtained by washing the intestines after opening them in luke-warm water in a large glass basin, whence they were removed by means of a pipette, being readily identified owing to their slight movements. Those occurring in the liver were obtained by teasing that organ in luke-warm water. Table I records the results of the examination of five crows for parasites. I am indebted to Miss Reynolds for the help she gave me in placing the material she collected at my disposal.

Dans un travail publié précédemment dans cette revue, nous avons montré que la concentration moléculaire du liquids cœlomique d'Ascaris megalocephala était voisine de Δ = − 0°, 63 avec de petites variations; d'après nos expériences, l'Ascaris était susceptible d'une régulation osmotique; il augmente de poids dans une solution hypotonique par rapport à son liquide; il y a pénétration d'eau; dans une solution hypertonique il diminue de poids (départ d'eau).

Circulating antigen levels and antibody responses in Schistosoma bovis-infected West African Dwarf goats were evaluated during infection and following treatment with praziquantel (60 mg/kg) 13 weeks post-infection. One day, 1 week and 4 weeks post-treatment, subgroups of goats were sacrificed and perfused for worm recovery. For comparison, parasite-free control animals were included. Blood and faecal samples were collected biweekly. Two gut-associated schistosome antigens, circulating cathodic and circulating anodic antigen (CCA and CAA) and 3 specific antibody responses (total Ig, IgG and IgM) were measured. For specific antibody detection, crude S. bovis adult worm and egg homogenates were used. The level of CCA in the infected groups was significantly elevated from the time of onset of egg excretion onwards. However, following treatment, the CCA litres dropped to control levels within 1 week post-treatment. Strong positive correlations were found between CCA levels and worm counts and faecal egg counts during peak egg excretion. The correlations of CAA and specific antibody litres to egg and worm counts were poor. The antibody responses were all significantly elevated in the infected goats during patency, but only marginally affected by the treatment. Hence, CCA proved to be superior by correlating strongly to the level of infection and by being a sensitive indicator of the effect of treatment.

Groups of R. appendiculatus ticks infected with T. parva were irradiated at doses varying from 0 to 32 krad and then applied to rabbits; 3 and 4 days later their salivary glands were removed, processed and examined. Increasing doses of irradiation resulted both in a decreased infection rate of ticks and a decrease in the number of parasite masses observed in infected ticks. No normal parasite masses were seen after doses of 4 krad or above.

Immunoactivation depends upon the antigen potential to modulate T-cell repertoires. The present study has enumerated the effect of 61 kDa recombinant Leishmania donovani co-factor-independent phosphoglycerate mutase (rLd-iPGAM) on mononuclear cells of healthy and treated visceral leishmaniasis subjects as well as on THP-1 cell line. rLd-iPGAM stimulation induced higher expression of interleukin-1β (IL-1β) in the phagocytic cell, its receptor and CD69 on T-cell subsets. These cellular activations resulted in upregulation of host-protective cytokines IL-2, IL-12, IL-17, tumour necrosis factor-α and interferon-γ, and downregulation of IL-4, IL-10 and tumour growth factor-β. This immune polarization was also evidenced by upregulation of nuclear factor-κ light-chain enhancer of activated B cells p50 and regulated expression of suppressor of mother against decapentaplegic protein-4. rLd-iPGAM stimulation also promoted lymphocyte proliferation and boosted the leishmaniacidal activity of macrophages by upregulating reactive oxygen species. It also induced 1·8-fold higher release of nitric oxide (NO) by promoting the transcription of inducible nitric oxide synthase gene. Besides, in silico analysis suggested the presence of major histocompatibility complex class I and II restricted epitopes, which can proficiently trigger CD8+ and CD4+ cells, respectively. This study reports rLd-iPGAM as an effective immunoprophylactic agent, which can be used in future vaccine design.

The isolation and molecular characterization of the gene coding for L14 ribosomal protein from L. braziliensis is described. There are 2 copies of the gene per haploid genome, repeated in a head-to-tail tandem orientation and located in a single chromosome of approximately 950 kb. Northern blot analyses indicate the presence of a single transcript of 0·95 kb which is up-regulated when parasites reach the stationary growth phase. L. braziliensis L14 gene codes for a 175 amino acid long polypeptide showing 75–83% sequence identity with L14 proteins from trypanosomatids and approximately 25% with its counterparts from higher eukaryotic organisms. L14 ribosomal proteins from trypanosomatids and higher eukaryotes share along their molecules a similar distribution pattern of theoretically functional domains. L. braziliensis L14 recombinant protein is not recognized by sera from cutaneous leishmaniasis patients. Immunization of mice with one dose of L14 recombinant protein and a second dose of L14 protein covalently linked to the HSP70 from Trypanosoma cruzi induces a high antibody level against this L14 protein, which is mostly of the IgG2a subtype, as well as a strong increase in splenocyte proliferation index.

In August, 1920, Dr Andrew Balfour, C.B., C.M.G., Director of the Wellcome Bureau of Scientific Research, received from Mr A. Pomeroy, F.E.S., Official Entomologist in South Nigeria, a tube containing some parasites from the “fore-gut” of a Cobra (Naia nigricollis Reinh.) from Ilaro, South Nigeria. Dr Balfour kindly handed these specimens to me for examination. The specimens were few in number, comprising only ten Nematodes and the two examples of Porocephalus described in the present Note. One of these examples at once attracted my attention by reason of its remarkable external form (Text-figure 1, A). I have consulted most of the available literature dealing with Porocephalus and the figure which, so far as I have discovered, most nearly approaches that of the present specimen is that of P. annulatus Baird, supplied by Shipley (his Text-figure 5, p. 59) in his memoir on the Linguatulidae. From my reproduction of Shipley's figure (Text-figure 1, C) it will be seen that Porocephalus annulatus, like the new species nowto be described, has a very narrow “neck,” but whereas in P. annulatus this neck is very short, in the new species it is comparatively very long; moreover, whereas in P. annulatus the cephalo-thorax (prosoma) is not longer than broad (or only slightly so in some specimens) and the first annulus of the “abdomen” (opisthosoma) is certainly no larger than succeeding annuli, in the new species the prosoma is roughly three times longer than it is broad and the first annulus is at least twice the size of the third at any succeeding annulus.

Insect parasitic nematodes have acquired mechanisms to evade their host immune response for successful parasitism. Despite the importance of understanding of the evolution of evasion mechanisms from host immunity, insect immune response against non-parasitic nematodes has not been well studied. In our previous study, we demonstrated that a non-insect parasitic nematode Caenorhabditis elegans was not encapsulated by haemocytes in the larvae of the greater wax moth Galleria mellonella. To understand how nematodes influence insect haemocytes to escape encapsulation, we examined the effect of C. elegans on haemocytes in the haemocoel of G. mellonella larvae. Injection of nematodes resulted in the decrease of haemocyte density while mortality and spreading ability of haemocytes, the haematopoietic organs were not affected. In vitro co-incubation of haemocytes with nematodes resulted in a decrease of haemocyte density and we observed feeding on haemocytes by nematodes. Injection of C. elegans feeding-delay mutants into insects did not cause the decrease of haemocyte density. The decrease of haemocyte density was due to the nematode's ingestion of haemocytes. Furthermore, an entomopathogenic nematode and other bacterial feeding nematodes also showed similar feeding behaviour. The nematode's ability to feed on haemocytes may have played an important role in the evolution of nematode parasitism in bacterial-feeding nematodes.

Four specimens of this trematode were obtained from the small intestine of Kachuga smithii in December 1929. Two of the specimens were not sexually mature; for thought they possessed well-developed testes, ovary and a very small receptaculum seminis, they lacked the uterus and ova. In one of these immature specimens the vitellarian follicles were very feebly developed.

The object of this paper is the description of a dipterous larva based on the study of six specimens of larvae obtained by Mr R. A. Phillips from living specimens of the snail Vertigo genesii Gredler which he had caught at Cloanascragh Bog, near Taum, Co. Galway. Three larvae were received in October 1933 through Prof. Boycott, and three in September 1936 directly from Mr Phillips. In a letter accompanying the specimens Prof. Boycott makes the following remark:

“Considering that the whole snail shell is only about 2 mm. × 1 mm. the larvae seem very big.” In fact some of the shells are distinctly smaller than the adult larvae, which when mounted are 2·0–5·0 mm. long, and 0·3–1·5 mm. in diameter.

The use of an electrically driven Sharples super-centrifuge for isolating viruses is described. The theory of sedimentation in such centrifuges is discussed and curves of the theoretical minimum sedimentation rates are given. The probability that convectionless sedimentation cannot take place in high-speed preparative centrifuges is discussed in relation to the theory of ‘differential centrifugation’.

Blastocystis spp. is the most frequent infectious unicellular, luminal parasite in all species of animals and humans. It has been linked to diarrhoea and irritable bowel syndrome. Saccharomyces boulardii (Sb) is a widely used probiotic that previously showed efficacy against several intestinal pathogens. The aim of this study was to investigate the therapeutic role of Sb on Blastocystis spp. Methods: Five groups of Blastocystis subtype-3 infected rats were treated with either live Sb alone, metronidazole (MTZ) alone, Sb extract, both Sb and MTZ, or placebo-treated besides the noninfected control group. Assessment of treatment effectiveness was done by study of parasitological cure rate, histopathological effect and analysis of the colonic mucosal level of mRNAs expressions for the proinflammatory cytokines interleukin-6 (IL-6), IL-8, tumour necrosis factor alpha (TNF-α) and Inducible nitric oxide synthase (iNOS) by real-time reverse transcription-polymerase chain reaction (real-time RT-PCR). Results showed that live Sb significantly improved the histological characteristics and decreased the cytokines and iNOS in the colonic mucosa. Co-administration of live Sb together with MTZ gave a better effect than other treatments and had early efficacy and revealed a 100% reduction of the parasite stages from both the stool and intestinal wash fluid.

In the course of studies of copepods parasitic on the market fishes of South India two of the most valued fishes, Scomberomorus commersoni and Stromateus niger, were found infested by large numbers of the blood-sucking parasites, Pseudocycnus armata Bas-sett-Smith and Lernanthropus konigii Steenstrup & Lutken. In the present paper the description of Pseudocycnus armata, which was first recorded by Bassett-Smith from Bombay and later by Kirtisinghe from Ceylon, is confined to a more accurate account of the appendages than has been given by these authors, while Lernanthropus konigii, which has not been recorded since it was established in 1861, is fully described.

Cyclin-dependent kinases (CDKs) have important roles in regulating key checkpoints between stages of the cell cycle. Their activity is tightly regulated through a variety of mechanisms, including through binding with cyclin proteins and the Cdc2/Cdc28 kinase subunit (CKS), and their phosphorylation at specific amino acids. Studies of the components involved in cell cycle control in parasitic protozoa are limited. Trichomonas vaginalis is the causative agent of trichomoniasis in humans and is therefore important in public health; however, some of the basic biological processes used by this organism have not been defined. Here, we characterized proteins potentially involved in cell cycle regulation in T. vaginalis. Three genes encoding protein kinases were identified in the T. vaginalis genome, and the corresponding recombinant proteins (TvCRK1, TvCRK2, TvCRK5) were studied. These proteins displayed similar sequence features to CDKs. Two genes encoding CKSs were also identified, and the corresponding recombinant proteins were found to interact with TvCRK1 and TvCRK2 by a yeast two-hybrid system. One putative cyclin B protein from T. vaginalis was found to bind to and activate the kinase activities of TvCRK1 and TvCRK5, but not TvCRK2. This work is the first characterization of proteins involved in cell cycle control in T. vaginalis.

Numbers of leucocytes in squirrels with gametocytes of Hepatozoon in their blood (infected) were compared with animals without gametocytes (uninfected). Typical values for leucocytes/mm3 blood in uninfected squirrels were: leucocytes 5·7×103, granulocytes 3·4×103, lymphocytes 2·0×103 and monocytes 0·3×103 cells. Infection caused an increase in monocytes, lymphocytes and granulocytes, and there was a significant positive association between parasitaemia level and numbers of both total leucocytes and monocytes. Infected animals had more uninfected monocytes/mm3 blood than did uninfected animals. The proportions of monocytes were more variable over time in infected animals, but no shift between infected and uninfected status was detected. Transfer of serum from infected squirrels to mice resulted in elevated counts of total blood leucocytes, monocytes and granulocytes, but not of lymphocytes, as compared with controls. Serum from squirrels with high parasitaemias had a more marked effect than serum from squirrels with low parasitaemias. Results indicate an infection-related monocytosis, possibly controlled by cytokines, that increases the number of cells available for invasion by gametocytes, thus enhancing the chances of parasite transmission.