Aspects of bovine herpesvirus 1 and bovine viral diarrhoea virus herd-level seroprevalence and vaccination in dairy and beef herds in Northern Ireland.

BACKGROUND: Infections with bovine herpesvirus 1 (BoHV-1) and bovine viral diarrhoea (BVD) virus cause diseases of cattle with a worldwide distribution. The primary objective of the present study was to describe aspects of herd-level BoHV-1 and BVDV seroprevalence (based on testing of pooled sera) and control on farms in Northern Ireland, including vaccine usage. An indirect antibody ELISA test (SVANOVA, Biotech AB, Uppsala, Sweden) was applied to serum pools which were constructed from serum samples taken for a cross-sectional study of a convenience sample of 500 Northern Irish dairy and beef cow herds in 2010, for which vaccination status was determined by telephone survey. The herd-level seroprevalence of BoHV-1 and BVDV in Northern Ireland was estimated in non-vaccinating herds and associations between possible risk factors (herd type and herd size (quartiles)) and herd-level prevalence were determined using chi-squared analysis. RESULTS: The herd-level seroprevalence (of BoHV-1 and BVDV) in non-vaccinating herds was 77.3% (95% CI: 73.6-80.9%) and 98.4% (95% CI: 97.3-99.5%) respectively in the cross-sectional study. A significant difference existed in BoHV-1 herd-level seroprevalence between dairy and beef herds (74.7% vs 86.5% respectively; p < 0.02) though not for BVDV seroprevalence (98.5% vs 98.3% respectively; p > 0.91). A significant association was found between herd size (quartiles) and herd-level classification for BoHV-1 herd-level seroprevalence based on cut-off percentage positivity (COPP) (p < 0.01) while no such association was found for BVDV (p = 0.22). 15.5% and 23.8% of farmers used BoHV-1 and BVDV vaccines, respectively. BoHV-1 vaccine was used in 30% of dairy herds and in 11% of beef herds, while BVDV vaccine was used in 46% and 16% of dairy and beef herds, respectively. CONCLUSIONS: The results from this study indicate that the true herd-level seroprevalences to bovine herpesvirus 1 and bovine virus diarrhoea virus in non-vaccinating herds in Northern Northern Ireland are 77.3% (95% CI: 73.6-80.9%) and 98.4% (95% CI: 97.3-99.5%), respectively. The present study will assist in guiding regional policy development and establish a baseline against which the progress of current and future control and eradication programmes can be measured.

Bovine viral diarrhoea virus seroprevalence and vaccination usage in dairy and beef herds in the Republic of Ireland.

BACKGROUND: Bovine viral diarrhoea (BVD) is an infectious disease of cattle with a worldwide distribution. Herd-level prevalence varies among European Union (EU) member states, and prevalence information facilitates decision-making and monitoring of progress in control and eradication programmes. The primary objective of the present study was to address significant knowledge gaps regarding herd BVD seroprevalence (based on pooled sera) and control on Irish farms, including vaccine usage. METHODS: Preliminary validation of an indirect BVD antibody ELISA test (Svanova, Biotech AB, Uppsala, Sweden) using pooled sera was a novel and important aspect of the present study. Serum pools were constructed from serum samples of known seropositivity and pools were analysed using the same test in laboratory replicates. The output from this indirect ELISA was expressed as a percentage positivity (PP) value. Results were used to guide selection of a proposed cut-off (PCO) PP. This indirect ELISA was applied to randomly constructed within-herd serum pools, in a cross-sectional study of a stratified random sample of 1,171 Irish dairy and beef cow herds in 2009, for which vaccination status was determined by telephone survey. The herd-level prevalence of BVD in Ireland (percentage positive herds) was estimated in non-vaccinating herds, where herds were classified positive when herd pool result exceeded PCO PP. Vaccinated herds were excluded because of the potential impact of vaccination on herd classification status. Comparison of herd-level classification was conducted in a subset of 111 non-vaccinating dairy herds using the same ELISA on bulk milk tank (BMT) samples. Associations between possible risk factors (herd size (quartiles)) and herd-level prevalence were determined using chi-squared analysis. RESULTS: Receiver Operating Characteristics Analysis of replicate results in the preliminary validation study yielded an optimal cut-off PP (Proposed Cut-off percentage positivity - PCO PP) of 7.58%. This PCO PP gave a relative sensitivity (Se) and specificity (Sp) of 98.57% and 100% respectively, relative to the use of the ELISA on individual sera, and was chosen as the optimal cut-off since it resulted in maximization of the prevalence independent Youden's Index.The herd-level BVD prevalence in non-vaccinating herds was 98.7% (95% CI - 98.3-99.5%) in the cross-sectional study with no significant difference between dairy and beef herds (98.3% vs 98.8%, respectively, p = 0.595).An agreement of 95.4% was found on Kappa analysis of herd serological classification when bulk milk and serum pool results were compared in non-vaccinating herds. 19.2 percent of farmers used BVDV vaccine; 81% of vaccinated herds were dairy. A significant association was found between seroprevalence (quartiles) and herd size (quartiles) (p < 0.01), though no association was found between herd size (quartiles) and herd-level classification based on PCO (p = 0.548). CONCLUSIONS: The results from this study indicate that the true herd-level seroprevalence to Bovine Virus Diarrhoea (BVD) virus in Ireland is approaching 100%. The results of the present study will assist with national policy development, particularly with respect to the national BVD eradication programme which commenced recently.

Aspects of bovine herpesvirus-1 infection in dairy and beef herds in the Republic of Ireland.

BACKGROUND: Infection with bovine herpesvirus-1 (BHV-1) causes a wide range of disease manifestations, including respiratory disease and abortion, with world-wide distribution. The primary objective of the present study was to describe aspects of BHV-1 infection and control on Irish farms, including herd-level seroprevalence (based on pooled sera) and vaccine usage. METHODS: The characteristics of a diagnostic indirect BHV-1 antibody ELISA test when used on serum pools were evaluated using laboratory replicates for use in the seroprevalence study. The output from this indirect ELISA was expressed as a percentage positivity (PP) value. A proposed cut off (PCO) PP was applied in a cross-sectional study of a stratified random sample of 1,175 Irish dairy and beef cattle herds in 2009, using serum pools, to estimate herd seroprevalence. The study was observational, based primarily on the analysis of existing samples, and only aggregated results were reported. For these reasons, ethical approval was not required. Bulk milk samples from a subset of 111 dairy herds were analysed using the same ELISA. Information regarding vaccine usage was determined in a telephone survey. RESULTS: A PCO PP of 7.88% was determined to give 97.1% sensitivity and 100% specificity relative to the use of the ELISA on individual sera giving maximization of the prevalence independent Youden's index, on receiver operating characteristics analysis of replicate results. The herd-level BHV-1 seroprevalence was 74.9% (95% CI - 69.9%-79.8%), with no significant difference between dairy and beef herds. 95.5% agreement in herd classification was found between bulk milk and serum pools. Only 1.8 percent of farmers used BHV-1 marker vaccine, 80% of which was live while 75% of vaccinated herds were dairy.A significant association was found between herd size (quartiles) and seroprevalence (quartiles). CONCLUSIONS: The results from this study indicate BHV-1 infection is endemic, although BHV-1 vaccines are rarely used, in the cattle population in Ireland.

Comparative sorting of neuroendocrine secretory proteins: a search for common ground in a mosaic of sorting models and mechanisms.

Endocrine, neuroendocrine and exocrine cells store regulated secretory proteins in secretory granules, while constitutive and constitutive-like secretory proteins are secreted directly without storage. Sorting of secretory proteins takes place in the trans-Golgi network (sorting for entry) or immature secretory granules (sorting by retention). The relative contribution of these sorting steps and the sorting signals and mechanisms involved in each step has been the subject of intense studies and debate in recent years. New evidence now suggests that: (1) two proteins with structurally similar sorting signals can use different sorting mechanisms; (2) one protein with multiple sorting signals can be sorted differently in different cell types; and (3) one cell type can recognize different sorting signals and use different sorting mechanisms. The latter finding suggests that sorting must be a regulated event. While the current image of sorting is complex, recent findings are pointing to common features that form a mosaic of related sorting mechanisms.

Solution structure of a neurotrophic ligand bound to FKBP12 and its effects on protein dynamics.

The structure of a recently reported neurotrophic ligand, 3-(3-pyridyl)-1-propyl(2S)-1-(3,3-dimethyl-1, 2-dioxopentyl)-2-pyrrolidinecarboxylate, in complex with FKBP12 was determined using heteronuclear NMR spectroscopy. The inhibitor exhibits a binding mode analogous to that observed for the macrocycle FK506, used widely as an immunosuppressant, with the prolyl ring replacing the pipecolyl moiety and the amide bond in a trans conformation. However, fewer favourable protein-ligand interactions are detected in the structure of the complex, suggesting weaker binding compared with the immunosuppressant drug. Indeed, a micromolar dissociation constant was estimated from the NMR ligand titration profile, in contrast to the previously published nanomolar inhibition activity. Although the inhibitor possesses a remarkable structural simplicity with respect to FK506, 15N relaxation studies show that it induces similar effects on the protein dynamics, stabilizing the conformation of solvent-exposed residues which are important for mediating the interaction of immunophilin/ligand complexes with molecular targets and potentially for the transmission of the neurotrophic action of FKBP12 inhibitors.

N- and C-terminal domains direct cell type-specific sorting of chromogranin A to secretory granules.

Chromogranins are a family of regulated secretory proteins that are stored in secretory granules in endocrine and neuroendocrine cells and released in response to extracellular stimulation (regulated secretion). A conserved N-terminal disulfide bond is necessary for sorting of chromogranins in neuroendocrine PC12 cells. Surprisingly, this disulfide bond is not necessary for sorting of chromogranins in endocrine GH4C1 cells. To investigate the sorting mechanism in GH4C1 cells, we made several mutant forms removing highly conserved N- and C-terminal regions of bovine chromogranin A. Removing the conserved N-terminal disulfide bond and the conserved C-terminal dimerization and tetramerization domain did not affect the sorting of chromogranin A to the regulated secretory pathway. In contrast, removing the C-terminal 90 amino acids of chromogranin A caused rerouting to the constitutive secretory pathway and impaired aggregation properties as compared with wild-type chromogranin A. Since this mutant was sorted to the regulated secretory pathway in PC12 cells, these results demonstrate that chromogranins contain independent N- and C-terminal sorting domains that function in a cell type-specific manner. Moreover, this is the first evidence that low pH/calcium-induced aggregation is necessary for sorting of a chromogranin to the regulated secretory pathway of endocrine cells.

Disruption of disulfide bonds exhibits differential effects on trafficking of regulated secretory proteins.

For several secretory proteins, it has been hypothesized that disulfide-bonded loop structures are required for sorting to secretory granules. To explore this hypothesis, we employed dithiothreitol (DTT) treatment in live pancreatic islets, as well as in PC-12 and GH(4)C(1) cells. In islets, disulfide reduction in the distal secretory pathway did not increase constitutive or constitutive-like secretion of proinsulin (or insulin). In PC-12 cells, DTT treatment caused a dramatic increase in unstimulated secretion of newly synthesized chromogranin B (CgB), presumably as a consequence of reducing the single conserved chromogranin disulfide bond (E. Chanat, U. Weiss, W. B. Huttner, and S. A. Tooze. EMBO J. 12: 2159-2168, 1993). However, in GH(4)C(1) cells that also synthesize CgB endogenously, DTT treatment reduced newly synthesized prolactin and blocked its export, whereas newly synthesized CgB was routed normally to secretory granules. Moreover, on transient expression in GH(4)C(1) cells, CgA and a CgA mutant lacking the conserved disulfide bond showed comparable multimeric aggregation properties and targeting to secretory granules, as measured by stimulated secretion assays. Thus the conformational perturbation of regulated secretory proteins caused by disulfide disruption leads to consequences in protein trafficking that are both protein and cell type dependent.

Inhibition of calmodulin-activated smooth-muscle myosin light-chain kinase by calmodulin-binding peptides and fluorescent (phosphodiesterase-activating) calmodulin derivatives.

Aspects of the biochemistry of calmodulin have been addressed that bear on its cell biological role as a mediator of Ca2+ regulation. Calmodulin-binding peptides derived from the amino acid sequence of smooth-muscle myosin light-chain kinase (MLCK) were characterized as inhibitors of calmodulin activation of MLCK-catalyzed phosphorylation of the smooth-muscle regulatory light chain (MLC). MLCK activity was determined by measuring the rate of formation of one of the reaction products, ADP, in a coupled enzymatic assay by continuous fluorimetric monitoring of NADH removal in 100 microM CaCl2 at ionic strength 0.15 M, pH 7.0 and 21 degreesC. The Km value of calmodulin was 3.5 nM, a value 16-35-fold greater than the Kd value of calmodulin for MLCK [Török, K., and Trentham D. R. (1994) Biochemistry 33, 12807-12820]. The different Km and Kd values are most likely associated with the rate-limiting step in MLC phosphorylation being associated with product release from MLCK. The values of the inhibition constants, Ki, were the following: Ac-R-R-K-W-Q-K-T-G-H-A-V-R-A-I-G-R-L-CONH2 (Trp peptide), 8.6 (+/-1. 4 sd) pM; Y4-analogue of Trp peptide (Tyr peptide), 7.3 (+/-0.1) nM; and A-R-R-K-W-Q-K-T-G-H-A-V-R-A-I-G-R-L-S-S (RS20-like peptide), 0. 11-0.39 nM. The Ki values were consistent with kinetically determined Kd values of the peptides to calmodulin. Kinetic determination of Kd values required the use of a fluorescently labeled calmodulin, 2-chloro-(epsilon-amino-Lys75)-[6-(4-N, N-diethylamino-phenyl)-1,3,5-triazin-4-yl]-calmodulin (TA-calmodulin).1 Since, as here, Lys75 is a convenient labeling site on calmodulin for the introduction of fluorescent probes, the biological activity of the Lys-modified calmodulins was evaluated. TA-calmodulin and calmodulin selectively modified by 1-N, N-dimethylaminonaphthalene-5-sulfonyl chloride (dansyl-C1) at Lys75 (dansyl-calmodulin) were characterized as activators of cyclic AMP phosphodiesterase (PDE) and inhibitors of MLCK. The Km value for dansyl-calmodulin was equal to that of calmodulin, and that of TA-calmodulin was 3.5-fold greater. TA-calmodulin and Lys75-labeled dansyl-calmodulin thus distinguish between PDE and MLCK being agonists to the former and antagonists to the latter.

Conformational dynamics and kinetics of peptide antagonist interactions with interleukin-1 receptor. Fluorescence studies using the NBD-labelled peptide AF12415.

Interleukin-1 plays a key role in the inflammatory response provoked by various disease states and inhibition of its action can bring therapeutic benefits. Steady-state and time-resolved studies of the intrinsic tryptophan fluorescence of the free soluble Type I form of interleukin-1 receptor (IL-1R) reveal that the rotational motions of the three major domains are strongly associated. Bound peptide antagonists are buried in hydrophobic regions, but a flexible association permits access to species from the aqueous phase. Ligand binding does not lead to rigidification of the receptor structure. The kinetics and mechanism of complex formation and dissociation, involving IL-1R with receptor antagonist protein (IL-1ra) and with peptides AF11733 (15 aa) and AF10961 (21 aa) were determined with the aid of peptide AF12415 (15 aa) labeled at its N-terminus by the NBD fluorophore, which exhibits a five-fold increase in emission intensity at 540 nm on binding of the peptide to IL-1R. The magnitude of the ON rate constant, typically 1 x 10(6) M-1 s-1, implies the existence of an intermediate 'encounter complex' involving interactions of low specificity. Readjustments of the initial encounter complex leads to a final complex where very specific interactions dominate. The first-order rate constant for this latter process is the most sensitive indicator of the true peptide affinity for the receptor binding site, and thus provides a better criterion than the apparent OFF rate (typically 2 x 10(-3) s-1) for discrimination of peptide antagonists.

Expression, purification and characterization of recombinant human proinsulin.

We have recently developed a method to produce native human proinsulin using a bacterial expression system. A proinsulin fusion protein was recovered from inclusion bodies and cleaved using cyanogen bromide. The released proinsulin polypeptide was S-sulfonated and purified by anion exchange chromatography. Following refolding, proinsulin was purified by reversed-phase high-performance liquid chromatography. Combined peptide mapping and mass spectrometric analysis indicated that the proinsulin contained the correct disulfide bridging pattern. This proinsulin will be used to study the specificity of the furin/PC family of converting enzymes by using it as a substrate in a recently developed assay.

MDL 74,180 reduces cerebral infarction and free radical concentrations in rats subjected to ischaemia and reperfusion.

The protective effect of MDL 74,180 (2,3-dihydro-2,2,4,6, 7-pentamethyl-3-(4-methylpiperazino)-methyl-1-benzofuran-5-ol dihydrochloride) and alpha-tocopherol analogue free radical scavenger, against cerebral ischaemia and reperfusion in conscious rats has been demonstrated. Tissue damage following middle cerebral artery occlusion (2 h) and reperfusion (8 days) was decreased by MDL 74,180 (0.1 and 1.0 mg/kg per h) infusion beginning 15 min before the onset of reperfusion and continuing for 2 h into the reperfusion period, in a dose-related manner. Nitroxide radical adducts, characterized and quantified by electron spin resonance spectroscopy, were formed on the addition of spin traps to homogenized rat brain tissue previously subjected to global ischaemia and reperfusion. The primary oxidative chain free radicals form diamagnetic intermediates whose slow homolytic decomposition subsequently yields the observed stable spin adducts. Infusion of MDL 74,180 (1-10 mg/kg per h) beginning 15 min before the induction of global cerebral ischaemia (20 min) until the end of reperfusion (5 min), led to a dose-dependent reduction in the final concentration of spin adducts.

Solution conformational dynamics of the C-terminal residues in endothelin-1 and some analogues: a time-resolved fluorescence study.

The rotational relaxation times of the single tryptophan residues in endothelin-1, [Ala1,3,11,15]endothelin-1, human pro-endothelin-1, the linear hexapeptide Ac-His-Leu-Asp-Ile-Ile-Trp which corresponds to the C-terminal residues 16-21 in endothelin-1, the cyclic pentapeptide BQ123, and several di- and tri-peptides possessing C-terminal tryptophan residues have been determined from time-resolved fluorescence anisotropy decays obtained by phase/modulation techniques. Fluorescence lifetime distribution widths have also been examined as predictors of conformational heterogeneity/restriction. A significant contribution from a slow rotational component supports either the persistence, on the nano-second timescale at least, of a non-flexible alpha-helical structure for the C-terminal tail residues of endothelin-1 in water as solvent, as seen in the X-ray crystallographic structure, or the interaction of the C-terminal tail residues 16-21 with the constrained disulfide-bridged core residues 1-15. This slow rotational contribution is less evident in the linear, acyclic tetraalanine analogue but greatly increased in pro-endothelin-1. In BQ123 the fluorescence characteristics support the occurrence of a dominant rotameric form involving the indole sidechain of the D-tryptophan residue (C alpha-C beta torsion angle chi 1 of 60 degrees, as previously determined by NMR.

Insulin stimulates hepatic lipogenesis in rainbow trout, Oncorhynchus mykiss.

The effects of the pancreatic hormones, insulin and glucagon, on rates of lipid biosynthesis in liver removed from rainbow trout, Oncorhynchus mykiss, were evaluated in vitro. Livers were removed from animals fasted for 30-36h, cut into ca. 1 mm(3) pieces, and incubated in the presence of various concentrations of salmon insulin (sINS), bovine insulin (bINS), or a combination of BINS and bovine/porcine glucagon (GLU). Lipid synthesis was evaluated by total lipid concentration, (3)H2O incorporation into total lipid, and by fatty acid synthetase activity. Both mammalian and sINS tended to increase tissue total lipid concentration in hepatic tissue incubated for 5h. Insulin also stimulated (3)H2O incorporation into total lipid in a dose-dependent manner. Bovine INS (2 × 10(-6) M) stimulated de novo synthesis nearly 6-fold over control rates; sINS (2 × 10(-6) M) stimulated label incorporation more than 7-fold over control rates. Glucagon inhibited INS-stimulated (3)H2O incorporation; whereas, GLU alone had no effect on lipid synthesis in liver pieces incubated 5h. Lipid class analysis indicated that bINS significantly stimulated (3)H2O incorporation into phospholipids, fatty acids, and triacylglycerols. The greatest accumulation of label was in the triacylglycerol fraction, where incorporation was stimulated 17-fold over control levels. Hepatic enzymatic analysis indicated that bINS also significantly stimulated lipogenic enzyme activity 9-fold above control levels. These results indicate that INS is an important regulator of lipid synthesis in the liver of trout.

Conformational studies of the 'RGD' containing peptide echistatin and close analogs by circular dichroism and fluorescence.

Echistatin, one of the smallest and most active natural disintegrins, and its [Trp13]echistatin, [Trp27]echistatin, [Phe13,Trp31]echistatin analogs have been investigated by far-UV circular dichroism spectroscopy and fluorescence spectroscopy. All analogs inhibited ADP-stimulated platelet aggregation with EC50 values between 30 and 50 nM. The analogs were related closely, both in the CD spectral properties, characteristic of turn conformations, and in the location of isodichroic points connected to conformational transitions upon temperature increase. The low fluorescence quantum yield for Trp13 of 0.018, which could be enhanced 2.7-fold by DTT reduction of the peptide, is ascribed to a close proximity of this Trp13 residue to a disulfide bond. Calculation of the efficiency of fluorescence resonance energy transfer (FRET) yielded distances of 11.5 +/- 0.8 A for Tyr31-Trp27 in [Trp27]echistatin, and more than 15 A for Tyr31-Trp13 in [Trp13]echistatin, in good agreement with the structure of echistatin deduced from earlier NMR-molecular modeling studies. Both Trp13 and Trp27 in the respective analogs were quenched effectively by acrylamide with bimolecular quenching constants of 3.36 x 10(9) M-1 s-1 and 3.72 x 10(9) M-1 s-1, respectively. Iodide anion had negligible quenching effect on Trp13, despite high exposure of this residue to water, but was only 2-fold less efficient than acrylamide in quenching Trp27 fluorescence. Steady-state fluorescence anisotropy data, together with mean fluorescence lifetimes of 1.25 ns for Trp13 and 3.84 ns for Trp27 derived from full fluorescence lifetime decay analyses, yielded long rotational relaxation times of 1.39 +/- 0.18 and 1.35 +/- 0.17 ns, respectively, for these residues comparable to the expected overall rotation time of the peptides. The 'RGD'-containing loop appears to be restricted in movement on the nanosecond timescale with respect to the compact core of the peptide.

Structure of neuropeptide Y dimer in solution.

The structure of porcine neuropeptide Y in 0.05 M CD3COOD/D2O was determined by nuclear magnetic resonance spectroscopy. Nuclear Overhauser spectra yielded 377 distances which define a helical segment formed by residues 11-36. An additional set of 24 distances were interpreted as intermolecular distances within a dimer. A combination of distance geometry calculations, energy minimization and molecular dynamics yielded a model of the dimer having antiparallel packing of two curved helical units whose hydrophobic sides form a well defined core. The N-terminus (residues 1-9) appears as an unstructured mobile segment. Large changes in the intrinsic fluorescence intensity of neuropeptide Y tyrosine residues allowed the determination of the dimer dissociation constant as 1.6 +/- 0.6 microM at pH 2-8 in aqueous buffers and also indicated the enclosure of several tyrosine residues in the hydrophobic environment of the interface region in the dimeric species. Fluorescence anisotropy data reveals the slow rotation of such shielded residues.

BQ-123, cyclo(-D-Trp-D-Asp-Pro-D-Val-Leu), is a non-competitive antagonist of the actions of endothelin-1 in SK-N-MC human neuroblastoma cells.

SK-N-MC cells, derived from a human neuroblastoma, respond to endothelin (ET) peptides with an increase in the free intracellular calcium concentration. The response is biphasic, with the secondary plateau phase being abolished or reduced by removal of extracellular Ca2+ or by the presence of 100nM nitrendipine. Restoration of Ca2+ to the bathing solution in cells stimulated by ET-1 in the absence of Ca2+ caused the plateau to reappear. The order of potency of ET family peptides was ET-2 greater than or equal to sarafotoxin S6b greater than or equal to ET-1 much greater than ET-3, suggesting that ETA receptors mediate the response. Sarafotoxin S6c and the C-terminal hexapeptide endothelin (16-21) were inactive in these cells. [Ala1,3,11,15]ET-1, a linear analogue of ET-1 which has been suggested to be a selective ETB receptor agonist, was a weak competitive antagonist of the actions of ET-1 in these cells. However, BQ-123, recently introduced as a selective and competitive antagonist at ETA receptors, was a potent non-competitive antagonist of ET-1 giving a 50% reduction in the maximum response at 6nM.

A prospective randomized trial of vagotomy in chronic duodenal ulceration.

In a prospective, randomized trial, 76 patients with duodenal ulceration treated by truncal vagotomy and pyloroplasty were compared with 77 patients who underwent highly selective vagotomy. A total of 149 patients was followed up for from 1 to 4 years, the average follow-up period being 2.6 years. There was no operative mortality and no significant difference in postoperative morbidity between the two groups. The incidence of recurrent ulceration was greater after highly selective vagotomy, but this difference was not statistically significant. The clinical results were comparable in each group, and although the incidence of diarrhoea and dumping was greater after vagotomy and pyloroplasty, this difference was not statistically significant.

Gastro--oesophageal reflux in late pregnancy.

Lower oesophageal sphincter pressure and fasting plasma gastrin and progesterone were measured in 31 women in the last trimester of pregnancy and in 10 healthy female control subjects. Eighteen of the pregnant women suffered from heartburn but 13 did not. All of the control subjects and 10 women from each of the two pregnant groups were tested for gastro--oesophageal reflux by direct measurement of intraluminal pH. The mean barrier pressure of the lower oesophageal sphincter was lower in both groups of pregnant women than in the controls (P less than 0-05) and the mean barrier pressure of the women with heartburn was lower than that of the pregnant women without heartburn, though this difference did not reach statistical significance. Eight of 10 of the pregnant women with heartburn had moderate or severe reflux, and3 of 10 of the pregnant women without heartburn also had moderate or severe reflux. Most women who reflux have heartburn, nevertheless, some asymptomatic women also reflux, and therefore all pregnant women must be considerered at risk from Mendelson's syndrome if subjected to a general anaesthetic for an emergency obstetric procedure.