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Acquisition of Helicobacter pylori occurs mainly in childhood. However, the mode of transmission remains unclear. To help elucidate this, 100 children attending for upper gastrointestinal endoscopy were investigated for the presence of H. pylori at various sites. H. pylori was detected in antral gastric biopsies by the rapid urease test (13 patients), culture (13 patients), histology (15 patients) and PCR (20 patients). Gastric juice was positive for H. pylori in 3 patients by culture and 11 patients by PCR. The dental plaque from 68% of gastric biopsy-positive patients (as determined by culture or PCR) and 24% of gastric biopsy-negative patients was positive for H. pylori by PCR. The presence of H. pylori in dental plaque was significantly associated with the presence of this organism in the stomach. H. pylori was detected by PCR in the faeces of 25% of gastric biopsy-positive children sampled. H. pylori was not cultured on any occasion from the oral cavity or faeces. The evidence from this study suggests that oral-to-oral transmission may be a possible mode of spread of H. pylori in children.

The randomly amplified polymorphic DNA (RAPD) assay was used to generate DNA fingerprints from clinical isolates of Staphylococcus haemolyticus isolated from patients treated with continuous ambulatory peritoneal dialysis and previously subjected to a combination of typing methods. The RAPD profiles generated with one of six randomly designed 10-mer primers allowed visual discrimination of strains. Good correlation with the original typing scheme was achieved but RAPD typing allowed discrimination of strains previously indistinguishable.

An experiment has been conducted to measure differences in cavity Q caused by various cavity surface treatments. A requirement of the experiment was that it show little sensitivity to the reassembly of the apparatus with various test pieces. We chose a coaxial half-wave resonator, with an outer conductor extending significantly beyond the length of the inner conductor. At 700 MHz the outer conductor acts as a cut-off tube, eliminating the need for electric termination and thus any RF-contacts that can influence the accuracy of the Q-measurements. The experiment is aimed at qualifying the performance of cyanide-copper plated GlidCop Al-15 LO-OX in comparison with that of a machined GlidCop Al-15 LO- OX surface. To maximize the sensitivity of the measurement we use a fixed outer conductor made of oxygen free electronic (OFE) copper and only replaced the inner conductor, which is mounted on a low-loss Teflon pedestal located in the low electric field region of the half-wave TEM mode. The Q-values of machined GlidCop Al-15 and cyanide-copper plated GlidCop Al-15 inner conductors are measured against the reference Q of the annealed OFE co-axial cavity. This extremely simple configuration allows a statistically significant number of repetitions of measurements and should provide accurate comparative measurements. The results will be useful for the community in deciding the surface treatments for high-Q copper accelerators. While outside of the scope of the qualification of the cyanide copper plating, two UBAC plated OFE copper pieces have been added to the comparison.

The transmission of Helicobacter pylori may occur by spread of organisms from gastric juice which has been introduced into the mouth by gastro-oesophageal reflux. The aim of this study was to quantify the load of H. pylori present in gastric juice available for transmission. Gastric antral biopsy and gastric juice samples were collected from 108 adult dyspeptic patients undergoing routine upper gastroscopy and the presence of H. pylori was determined. In all, 54 (50%) of 108 patients gave positive results in the gastric antral biopsy rapid urease test and for H. pylori histology. The gastric juice of 40 (37%) of patients gave positive results for the urease A gene by PCR assay; 34 (31%) of patients were positive by these three tests and H. pylori was cultured from the gastric juice of 13 (38%) of these patients. The median count of H. pylori in gastric juice was 1.75 x 10(1) cfu/ml. Viable organisms in gastric juice may lead to transmission of H. pylori when refluxed or vomited into the mouth.

To assess the influence of incubation conditions on the resistance of Helicobacter pylori this study compared the effect of micro-aerophilic and anaerobic incubation followed by micro-aerophilic incubation on the measurement of metronidazole resistance of 102 H. pylori isolates, by both disk diffusion and Epsilometer (E)-tests. Anaerobic incubation for 24 h before micro-aerophilic incubation for 48 h consistently increased metronidazole activity in both assay methods. Although statistically significant, this was microbiologically less significant, as only 4 of 102 isolates gave discrepant readings (all four were resistant in micro-aerophilic conditions but susceptible in anaerobic/micro-aerophilic conditions). In all four cases variation was by a few millimeters in zone size (i.e., all were close to the cut-off point). There was 100% agreement between disk diffusion and E-test results. Of 104 observations (52 duplicate assays: 13 strains, two atmospheric conditions, two methods of determining resistance) there was 100% intra-observer and inter-observer agreement with regard to susceptibility and resistance status for both E-test and disk diffusion methods. Anaerobic incubation followed by micro-aerophilic incubation had little effect on the estimation of prevalence of metronidazole resistance and seemed to add little, if any, significant advantage over micro-aerophilic incubation alone.

A species of epiphytic Prorocentrum (Dinophyta, Prorocentrales), collected from the macroalga Dictyota dichotoma, was brought into culture. Based on morphological characteristics, this isolate was identified as Prorocentrum belizeanum. Analysis of the culture extract using high-performance liquid chromatography and liquid chromatography–mass spectrometry indicated the production of okadaic acid, a toxic polyether linked with the human diseases, diarrhetic shellfish poisoning and ciguatera fish poisoning.

The 6450 A ammonia absorption band in the atmosphere of Jupiter was observed during the summers of 1973 and 1974. High-dispersion spectra of this band were obtained and analyzed on a line-by-line basis to derive ammonia abundances in the Jovian atmosphere. The abundances determined this way show strikingly large fluctuations.

Four weed species (Bromus mollis, Vulpia sp., Poa annua, Steltaria media) occur in 30% or more of all perennial ryegrass seed samples. Of the listed undesirable species, Avena fatua (wild oat) and Hordeum murinum occurred respectively in 5.3 and 3.5% of ryegrass seedlots. Only 6 herbicides are registered for use in grass seed crops in New Zealand, 2 for wild oat, and 4 for broadleaved weeds. The results of research on weed control in seedling and established seed crops (ryegrass, cocksfoot, tall fescue, phalaris, prairie grass) are presented. Fertilisers for grass seed crops discussed are nitrogen (N), phosphorus (P), potassium (K), lime and zinc. Autumn N is commonly used and will increase seed yields in early flowering species (Pestuca rubra, F. arundinacea), but in ryegrass variable results have occurred. Spring N should be applied at stem elongation. No responses to P have been reported for ryegrass, while in established cocksfoot responses to P and K have been reported. Overliming can induce Zn deficiencies, and of the grass species only prairie grass may require lime. Keywords: Lolium, ryegrass, seed production, weed occurrence, Bromus mollis, herbicides, fertilisers, nitrogen, phosphorus, potassium, lime, zinc

Keywords: seedlots, Lolium spp, germination, blind seed disease, heating damage, physical purity, weed seed contamination, seed certification.

A Program Research and Development Announcement (PRDA) was initiated by DOE to solicit from industry new and novel ideas for improvements in the nuclear waste management system. GA Technologies Inc. was contracted to study a system utilizing a universal canister which could be loaded at the reactor and used throughout the waste management system. The proposed canister was developed with the objective of meeting the mission requirements with maximum flexibility and at minimum cost. Canister criteria were selected from a thorough analysis of the spent fuel inventory, and canister concepts were evaluated along with the shipping and storage casks to determine the maximum payload. Engineering analyses were performed on various cask/canister combinations. One important criterion was the interchangeability of the canisters between truck and rail cask systems. A canister was selected which could hold three PWR intact fuel elements or up to eight consolidated PWR fuel elements. One canister could be shipped in an overweight truck cask or six in a rail cask. Economic analysis showed a cost savings of the reference system under consideration at that time.