The reputed toxic and destructive action of certain species of Chara led to the preparation of watery and alcoholic extracts of Chara foetida and C. hispida which were sent to me with the request that the larvicidal power of these extracts should be tested.

Antigens were extracted from the epicuticle/cuticle of intact female Onchocerca volvulus using 2% 2-β-mercaptoethanol and 1% SDS. In Western blot analysis a human infection serum selected for its high antibody titre against whole worm homogenates did not recognize any component solubilized by 1% SDS. However, the same serum did bind at least 7 antigens among the material extracted with 2-β-mercaptoethanol. These antigens have apparent molecular weights (Mr) of: 15 000, 18 000, 28 000, 78 000, 98 000, 120 000 and 200 000. In ELISA using this preparation as target antigen, 151 out of 153 human infection sera gave positive results. An Onchocerca-specific IgG1 monoclonal antibody, designated Cam1, recognized the 28 000 Mr antigen, which is the most prominent antigen detected by Western blot analysis using human infection sera. In ELISA, using material affinity-purified with Cam1 as target antigen, 149 out of 153 human infection sera gave a positive IgG response. From a cDNA library three expressing clones were isolated with a rabbit serum raised against 2-β-mercaptoethanol solubilized material. One of these clones was recognized by the monoclonal antibody Cam1.

Six new species of cestodes from birds have been described. These are: Ophryocotyle indicus from the Rufous Babbler, Turdoides subrufus; Biuterina dicruri from the Grey Drongo, Dicrurus leucophaeus longicaudatus; Choanotaenia tandani from the Himalayan Whistling Thrush, Myiophoneus caeruleus temminckii; Choanotaenia picusi from the Scalybellied Green Woodpecker, Picus squamatus; Panuwa stylicirrosa from the Little Scalybellied Green Woodpecker, Picus xanthopygaeus; and Anoncotaenia indica from the Rufous-bellied Niltava, Muscicapa sundara.

The following is supplementary to the previous lists (Leigh-Sharpe, 1926 and 1933), and consists of records of parasitic Copepoda taken by workers in that group who have visited the Laboratory of the Marine Biological Association, Plymouth, during 1933.

Two species of the genus Stephanochasmus have been found in the fishes examined for parasites at the station of the Carnegie Institution of Washington, situated on the island of Tortugas in the Gulf of Mexico. These are S. casus Linton and S. sentus Linton. The anatomy of these worms contains several novel and interesting features, and that of the first named will be described here in detail.

The parasite herein described was found in the intestinal contents of Blatta americana at Calcutta. The species seems to be comparatively rare and was observed twice only. It may be named B. blattarum sp. nov.

Female sex pheromone reception was inhibited in a bioassay by treating males of the beet cyst nematode, Heterodera schachtii, with the sulphydryl reagent, mersalyl acid. This effect was blocked by the sulphydryl group protectant, dithiothreitol, indicating the occurrence of sulphydryl groups in the receptor molecules and a role for sulphydryl groups in pheromone reception.

As a major morphological feature in establishing the form of the nervous system, it is recognized that neurons are initially overproduced, then naturally occurring cell death reduces the neuron number to the functional requirement. However, the mechanisms controlling the selective elimination of certain neurons during a general phase of cell death are not fully understood. One event that seems to be pivotal is the establishment of neural connections, the degree of which may be influential regarding the fate of specific neurons. However, little quantitative evidence is available to either support or refute this theory. In this current study, a Stereological measurement of gap junction per neuron was carried out within the invertebrate model system of the tapeworm metacestode Mesocestoides corti, which has previously been shown to overproduce neurons during the asexual reproduction stage of its life-cycle. Novel Stereological estimation methods with ‘ vertical sections’ indicated that prior to asexual division the cerebral ganglion possessed approximately 268 neurons, each with a gap junction surface area of 250 μm2. As division progressed, the neuron number increased to approximately 700, while the total surface area of gap junction remained statistically unchanged. As a result the surface area of gap junction per neuron decreased to 106 μm2, less than half that in the undividing stage. These results provide the first non-biased quantitative data regarding changes in the mean surface area of gap junction per neuron in a developing cerebral ganglion.

Endotoxaemia has been described in cases of Human African trypanosomiasis (HAT), but it is unclear if this phenomenon influences inflammatory pathology either in the periphery or central nervous system (CNS). We studied endotoxin concentrations in the plasma and cerebrospinal fluid (CSF) of Trypanosoma brucei rhodesiense patients using the chromogenic Limulus Amoebocyte lysate assay. The relationship of endotoxin concentration to the presentation of gross signs of inflammation and the inflammatory/counter-inflammatory cytokine profile of the relevant compartments were analysed. We demonstrate that HAT patients exhibit parasitaemia-independent plasma endotoxaemia, and that this is associated with splenomegaly and lymphadenopathy. Endotoxin concentrations normalize rapidly after treatment. There was no evidence of endotoxin release in the CNS. A rapid normalization of endotoxin levels after treatment and lack of association with parasitaemia suggest that gut leakage is the main source of endotoxin in the circulation. Low CSF endotoxin concentrations and a lack of any association with neuroinflammatory markers or neurological sequelae suggest that endotoxin does not play a role in the pathogenesis of the disease in the CNS.

Vaccination remains the best hope for control of all forms of leishmaniasis, and the development of a safe and effective vaccine is a critical global public-health priority. Our previous work showed that immunization with non-persistent phosphomannomutase-deficient (ΔPMM) Leishmania major parasites confers significant protection in susceptible BALB/c mice due to increased T-cell numbers and suppression of IL-10 and IL-13 early during infection. Here, we complemented the ΔPMM L. major parasites with human PMM2 to determine whether we could further improve the protection. Complemented ΔPMM parasites have restored glycoconjugate biosynthesis, while retaining avirulence of the parental knockout strain. Immunization with hPMM2 add-back parasites showed similar Th1/Th2 cytokine profiles to that observed in ΔPMM-vaccinated mice. However, the numbers of the activated CD4+CD44hi and CD8+CD44hi T cells recruited to the draining lymph nodes early after Leishmania infection were reduced, leading to decreased protection following hPMM2-immunization. Thus, the magnitude of T-cell responses early in the infection and the absence of mannose-rich glycoconjugates determine the protective outcome of anti-leishmanial immunity.

Entamoeba histolytica is an intestinal parasite and the causative agent of amoebiasis, which is a significant source of morbidity and mortality in developing countries. Although anti-amoebic drugs such as metronidazole, emetine, chloroquine and nitazoxanide are generally effective, there is always potential for development of drug resistance. In order to find novel targets to control E. histolytica proliferation we cloned, expressed and purified thymidine kinase (Eh-TK) and uridine-cytidine kinase (Eh-UCK) from E. histolytica. Eh-TK phosphorylates thymidine with a Km of 0·27 μm, whereas Eh-UCK phosphorylates uridine and cytidine with Km of 0·74 and 0·22 mm, respectively. For both enzymes, ATP acts as specific phosphate donor. In order to find alternative treatments of E. histolytica infection we tested numerous nucleoside analogues and related compounds as inhibitors and/or substrates of Eh-TK and Eh-UCK, and active compounds against E. histolytica in cell culture. Our results indicate that inhibitors or alternative substrates of the enzymes, although partially reducing protozoan proliferation, are reversible and not likely to become drugs against E. histolytica infections.

A flagellate of the genus Bodo is described, which was found in the faeces of a man on 4 occasions during a period of 12 days, sources of extraneous contamination being excluded from the last 3 specimens. Although morphologically it is identical with Bodo, it differs from other known members of this genus in that it multiplies more readily at 37°C. than at lower temperatures.