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The upland water supply from Loch Katrine to Glasgow was unfiltered at the time of investigations reported here. Continuous monitoring of Cryptosporidium oocysts in water treatment works final water entering supply was a regulatory requirement from 2000, using a sampling and analysis protocol for low turbidity water that filtered 1,000 litre samples at site. Cryptosporidium surveillance was extended across the supply by developing a continuous monitoring programme for operational surveillance of raw waters, using the same sampling and analysis protocol. During 2001–2004 six final water samples exceeded 0.1 oocysts per 10 litres, but none exceeded 1 oocyst per 10 litres. Cryptosporidium 90th and 95th percentiles for source waters from three catchments were significantly lower for April–June than each of the other quarters ( p

Sordaria brevicollis is a filamentous ascomycete previously considered to be exclusively heterothallic. Here we show that S. brevicollis can exhibit homothallism, and describe the genetic and environmental factors favouring the process. Both mating types can produce perithecia in unmated cultures, but only in the uncrossed perithecia of mtA are ascospores formed (in

The anthelmintic pyrantel is believed to act as an agonist at acetylcholine receptors on somatic muscle from the parasite Ascaris suum. This study aimed to confirm this mode of action of pyrantel. Single-channel recordings from muscle vesicles formed from the extrasynaptic region of the bag of somatic muscle cells of Ascaris suum were made using the patch-clamp technique. Pyrantel (0.03-100 microM) activated cation-selective channels with at least 2 conductance levels: main conductance 41 +/- 2.04 pS (mean +/- S.E., n = 28), smaller conductance 22.4 +/- 0.34 pS (mean +/- S.E., n = 8). The current/voltage plots showed a linear relationship. Detailed kinetic analysis revealed that activation of the receptor by pyrantel resulted in at least 2 distinct open and burst states and at least 3 distinct closed states. The mean open time of the channel, with 0.1 microM pyrantel, was 1.53 +/- 0.22 ms (mean +/- S.E., n = 7) at -75 mV. We have previously shown that acetylcholine activated channels with similar properties to the pyrantel-activated channels (Pennington, A.J. and R.J. Martin, 1990, J. Exp. Biol. 154, 201) confirming that pyrantel is an acetylcholine agonist. With high concentrations (100 microM) of pyrantel a sequence of rapid openings and closings of the channel was observed, indicating the presence of an open channel block. Previous experiments have shown that the anthelmintic levamisole, which also acts as an acetylcholine agonist on this preparation, induced channel block at hyperpolarised potentials with high concentrations (Robertson, S.J. and R.J. Martin, 1993, Br. J. Pharmacol. 108, 170). A comparison is made of the actions of the 3 agonists pyrantel, levamisole and acetylcholine at the nicotinic receptor in Ascaris muscle, and implications for the therapeutic use of the compounds are discussed.

The patch-clamp technique was used to examine activation by levamisole of nicotinic acetylcholine receptors in muscle vesicle preparations from Ascaris suum. Previous experiments have shown that levamisole, when applied at concentrations greater than 30 μM to the extracellular surface of the membrane, activated channels which showed characteristics of a voltage-sensitive open channel-block and desensitisation. In this study initial experiments were performed where channels were activated with levamisole (2 μM) applied in the patch-pipette. Isolated inside-out patches were used. In addition, levamisole (30-926 μM) was added to the cytoplasmic membrane surface via the bath solution. In eight out of nine experiments, addition of levamisole to the bath solution resulted in an increase in channel activity, a voltage-sensitive open channel-block and desensitisation. The open channel-block occurred at hyperpolarised potentials, an observation consistent with levamisole (a cationic substance) blocking the channel from the extracellular surface. Thus it was concluded that levamisole crossed from the cytoplasmic side of the membrane, via the lipid phase, to the extracellular surface of the patch. In the presence of high cytoplasmic concentrations of levamisole, open channel-block was not observed at depolarised potentials, suggesting channel asymmetry.

The specific activity of NAD(+)-dependent 15-hydroxyprostaglandin dehydrogenase (PGDH) was found to increase in the ovaries of pregnant and pseudopregnant rabbits. The mean specific activity of cytosolic ovarian PGDH in 14- to 28-day pregnant rabbits was 24.3 +/- 8.1 nmol NADH formed/min/mg protein (n = 16) using PGE1 as substrate whereas in nonpregnant rabbits the specific activity was 1.5 +/- 0.8 nmol NADH formed/min/mg protein (n = 8). The reaction was dependent on NAD+; NADP+ did not support the reaction. In grouping the PGDH activities from pregnant rabbits into second (14-18 days) and third (2-28 days) trimester periods, no significant difference between values was found (26.1 +/- 8.9 vs 23.4 +/- 8.1 nmol NADH formed/min/mg protein, respectively). Western blot analysis of the ovarian cytosol using an antibody which was made to the purified lung PGDH of pregnant rabbits recognized an ovarian protein of identical molecular mass (30 kDa). Ovarian PGDH activities were also examined in rabbits treated with pregnant mare's serum gonadotrophin (PMSG) and human chorionic gonadotrophin (hCG) to induce a state of superovulatory/pseudopregnancy and only on day 11 following hCG treatment was an increase in PGDH specific activity observed. On day 11, the specific activity was 14.8 +/- 4.3 nmol NADH formed/min/mg protein whereas values on days 10 and 12 were only 1.1 +/- 1.1 and 1.0 +/- 0.8, respectively. PGDH activities on days 3, 7 and 16 were also low.(ABSTRACT TRUNCATED AT 250 WORDS)

The role of the canonical NF-kappaB pathway in mammary tumorigenesis was investigated using a transgenic (TG) mouse expressing a dominant-negative inhibitor of kappaB (IkappaBalpha(SR (S32A/S36A))) in the mammary gland under the control of the mouse mammary tumor virus promoter (MMTV). TG and control mice were subjected to a chemical carcinogenesis protocol. Hyperkeratinized squamous metaplasias (cytokeratin-6+/p63+) sometimes with a basaloid island component, were found in both TG and control mice whereas luminal (cytokeratin-19+/MUC1+) ErbB2+ papillary and adenomatous lesions developed almost exclusively in control mice. p65/RelA- and NF-kappaB DNA-binding activity were detected in mammary luminal lesions, but rarely in squamous metaplasias. Analysis of NF-kappaB family proteins and target genes using microarray data from a cohort of human mammary tumors revealed the expression of a canonical NF-kappaB pathway, but not non-canonical pathway proteins in HER2+ luminal cancers. HER2+ tumors also showed differential regulation of specific NF-kappaB target genes relative to basal and ER+ luminal cancers. Isolation of mammary cell populations enriched for stem and progenitor cell characteristics from an NF-kappaB-EGFP reporter mouse by fluorescence-activated cell sorting demonstrated that luminal progenitors contain activated NF-kappaB whereas the mammary stem cell-enriched population, does not. Together these data suggest that the canonical NF-kappaB pathway is active in normal luminal progenitor cells before transformation and is required for the formation of mammary luminal-type epithelial neoplasias.

The organization ofAscarismotoneurones and nervous system is summarized. There is an anterior nerve ring and associated ganglia, main dorsal and ventral nerve cords which run longitudinally, and a small set of posterior ganglia. Cell bodies of motoneurones are found in the ventral nerve cord and occur in 5 repeating ‘segments’; each contains 11 motoneurones. Seven morphological types of excitatory or inhibitory motoneurone are recognized.EachAscarissomatic muscle cell is composed of the contractile spindle; the bag region, containing the nucleus; the arm; and the syncytial region, the location of neuromuscular junctions. The resting membrane potential of muscle is approximately — 30 mV and shows regular depolarizing, Ca-dependent ‘spike potentials’ superimposed on smaller Na+- and Ca2+-dependent ‘slow waves’ and even slower ‘modulation waves’. The membrane shows high Cl-permeability. Adjacent cells are electrically coupled so that electrical activity in the cells is synchronized. Acetylcholine (ACh) and γ-aminobutyric acid (GABA) affect the electrical activity. Bath-applied ACh increases membrane cation conductance, depolarizes the cells, alters the frequency and amplitude of spike potentials and produces contraction. Bath-applied GABA increases Cl-conductance, decreases spike activity and causes hyperpolarization and muscle relaxation.The extra-synaptic ACh receptors on the bag region ofAscarismuscle can be regarded as a separate subtype of nicotinic receptor. ACh and anthelmintic agonists (pyrantel, morantel, levamisole) produce a dose-dependent increase in cation conductance and membrane depolarization which is blocked by tubocurarine, mecamylamine but not by hexamethonium. The potency, of GABA agonists, with the exception of sulphonic acid derivatives, correlates with the vertebrate GABAareceptor. The potency of antagonists does not. Thus, bicuculline, securinine, pitrazepine, SR95531 and RU5135 are potent vertebrate GABAaantagonists but have little effect on GABA receptors. The potency order of the arylaminopyridazine GABA antagonists: SR95103, SR95132, SR42666, SR95133, SR95531, SR42627 and SR42640 at theAscarisGABA receptors contrasts with that at vertebrate GABAareceptors. It has been suggested that the receptor is referred to as a GABAnreceptor.Patch-clamp studies show that ACh activates a non-selective cation channel which has a main conductance of 40–50pS and apparent mean open time of 1·3 ms; a smaller channel of 20–30 pS with a similar open-time is also activated. Pyrantel and levamisole also produce openings with similar conductances and open-times. GABA activates a Cl-channel with a main state conductance of 22 pS and an apparent mean open duration of 32 ms; conductance states of 10 and 15 pS are also seen. Piperazine similarly activates this channel but the mean open-time is shorter (14 ms). Ivermectin in high doses, is an antagonist which reduces the GABA channel conductance and Popen; it does, however, open ‘small’ Cl-channels when applied to the outside surface of membrane. These channels have a conductance of 9–15 pS and very long open times (> 100 mS). 5-HT does not have a direct effect on membrane potential or conductance but acts on cAMP levels and glycogen metabolism. Dopamine, octopamine and AF1 may act as neurotransmitters or neuromodulators.

Objective: To assess the relation between tap water lead and maternal blood lead concentrations and assess the exposure of infants to lead in tap water in a water supply area subjected to maximal water treatment to reduce plumbosolvency. Design: Postal questionnaire survey and collection of kettle water from a representative sample of mothers; blood and further water samples were collected in a random sample of households and households with raised water lead concentrations. Setting: Loch Katrine water supply area, Glasgow. Subjects: 1812 mothers with a live infant born between October 1991 and September 1992. Blood lead concentrations were measured in 342 mothers. Main outcome measures: Mean geometric blood lead concentrations and the prevalence of raised tap water lead concentrations. Results: 17% of households had water lead concentrations of 10 μg/l (48.3 nmol/l) or more in 1993 compared with 49% of households in 1981. Tap water lead remained the main correlate of raised maternal blood lead concentrations and accounted for 62% and 76% of cases of maternal blood lead concentrations above 5 and 10 μg/dl (0.24 and 0.48 μmol/l) respectively. The geometric mean maternal blood lead concentration was 3.65 μg/dl (0.18 μmol/l) in a random sample of mothers and 3.16 μg/dl (0.15 μmol/l) in mothers whose tap water lead concentrations were consistently below 2 μg/l (9.7 nmol/l). No mother in the study had a blood lead concentration above 25 μg/dl (1.21 μmol/l). An estimated 13% of infants were exposed via bottle feeds to tap water lead concentrations exceeding the World Health Organisation9s guideline of 10 μg/l (48.3 nmol/l). Conclusions: Tap water lead and maternal blood lead concentrations in the Loch Katrine water supply area have fallen substantially since the early 1980s. Maternal blood lead concentrations are well within limits currently considered safe for human health. Tap water lead is still a public health problem in relation to the lead exposure of bottle fed infants. Key messages For a given tap water lead concentration mater- nal blood lead concentrations are much lower than they were in 1981 Tap water lead remains the main correlate of raised maternal blood lead concentrations An estimated 13% of infants are exposed via bottle feeds to tap water lead concentrations of 10 μg/l (48.3 nmol/l) or more Maternal blood lead concentrations are generally within limits considered safe for human health

1. The patch-clamp technique was used to examine levamisole-activated channels in muscle vesicles from Ascaris suum. Cell-attached and isolated inside-out patches were used. 2. Levamisole (1-90 microM), applied to the extracellular surface, activated channels which had apparent mean open-times in the range 0.80-2.85 ms and linear I/V relationships with conductances in the range 19-46 pS. Ion-replacement experiments showed the channels to be cation selective. 3. The kinetics of the channels were analysed. Generally open- and closed-time distributions were best fitted by two, and three exponentials respectively, indicating the presence of at least two open states and at least three closed states. The distributions of burst-times were best-fitted by two exponentials. 4. Channel open- and burst-times were voltage-sensitive: at low levamisole concentrations (1-10 microM), they increased with hyperpolarization. At higher concentrations of levamisole (30 microM and 90 microM) flickering channel-block was observed at hyperpolarized potentials. Using a simple channel-block model, values for the blocking dissociation constant, KB were determined as 123 microM at -50 mV, 46 microM at -75 mV and 9.4 microM at -100 mV. 5. At the higher concentration of levamisole (30 microM and 90 microM) long closed-times separating 'clusters' of bursts were observed, at both hyperpolarized and depolarized membrane potentials and this was interpreted as desensitization.

A fluorescent derivative of the anthelmintic ivermectin (4''-5,7-dimethyl bodipy proprionylivermectin, referred to hereafter as bodipy ivermectin) was synthesized for an investigation of the distribution of avermectins. Injected into adult Ascaris suum at doses greater than 0.1 micron per worm, it produced a dose-dependent immobilization. Fluorescent microscopy of frozen sections revealed the distribution of the probe in the whole nematode. Staining of collagenase-isolated muscle cells was studied using bath application of bodipy ivermectin. The trypan-blue quenching technique showed that the ivermectin probe was located in the outer monolayer of the muscle membrane. The cytoplasm was not stained. The interpretation of these observations is discussed in view of the known lipophilic nature of avermectins. Staining of the muscle membrane and nerve cord is consistent with the view that avermectins act at these sites. The significance of the hypodermal and lateral line staining is also discussed.